Final Report
Transcription
Final Report
Final Report Texas Environmental Research Consortium Project H-3 Emissions Inventory Associated with Forest, Grassland, and Agricultural Burning during the Texas Air Quality Study Submitted by: David Allen Anil Katamreddy Victoria Junquera Jan Decabooter Center for Energy and Environmental Resources The University of Texas Austin, Texas Submitted to: Anne Brun Texas Environmental Research Consortium FINAL REPORT December 15, 2002 EXECUTIVE SUMMARY An inventory of emissions of total particulate matter (PM), particulate matter smaller than 10 microns in aerodynamic diameter (PM10), particulate matter smaller than 2.5 microns in aerodynamic diameter (PM2.5), nitrogen oxides (NOX), non-methane hydrocarbons (NMHC), carbon monoxide (CO), carbon dioxide (CO2), methane (CH4) and ammonia (NH3) from outdoor fires was performed for the period of August 1 to September 30, 2000. The domain over which fire emissions were estimated encompassed multiple states and was centered on the Houston/Galveston-Beaumont/Port Arthur (HGBPA) region. The methodology employed in this study was based on the work of Dennis (2002). Information on fire location and acreage burned was gathered from various state and federal agencies for each day of the study period. Fuel loadings (in tons/acre) were calculated for each fire, based on land use data specific for the state of Texas, as well as comprehensive national sources of data. Emission factors (in pollutant emission rate per ton of fuel burned) were based on literature data. Wildfires were the main source of emissions during the study period. Agricultural, slash and prescribed burns were found to contribute relatively little to emissions during the study period, due to severe drought conditions during the summer of 2000. The emissions exhibited considerable variability. On a day of moderate fire activity, such as August 31, emissions from wildfires were estimated to be 1300, 92, 120, and 11 short tons of CO, NMHC, PM2.5, and NOX, respectively. On one of the days with the highest fire activity, September 4, wildfire emissions were estimated to be 3709, 255, 334, and 48 short tons of CO, NMHC, PM2.5, and NOX, respectively. These emissions were significant compared to other emission sources in the region. For example, emissions of CO, NMHC from wildfires exceeded emissions from light duty gasoline vehicles in the 8county Houston/Galveston area on several days between August 31 and September 8, 2000. The ultimate goal of this study was to generate an emissions input file suitable for use in the photochemical model used by the State of Texas to evaluate regulatory policies (the Comprehensive Air Quality Model, with extensions, CAMx). For the model-ready input file, NMHC emissions were classified according to Carbon Bond IV (CB-IV) reaction classes, and the plume rises of the fires were based on calculations using the CALPUFF and FIREPLUME models. ii Table of Contents 1. Introduction..................................................................................................................... 1 2. Collection and Assembly of Fire History Data............................................................... 3 2.1 Overview of Approach.............................................................................................. 3 2.2 Wildfires ................................................................................................................... 3 2.3 Agricultural, Prescribed Range, and Slash Burning ................................................. 5 2.3.1 Agricultural Burns ............................................................................................. 5 2.3.2 Prescribed Range Burning ................................................................................. 6 2.3.3 Slash Burning..................................................................................................... 6 2.3.3.1 Logging debris ............................................................................................ 7 2.3.3.2 Land Clearing Debris.................................................................................. 7 3. Estimation of Fuel Loading and Consumption Factors for Wildfires............................. 7 3.1 Overview of Approach.............................................................................................. 7 3.2 State of Texas............................................................................................................ 8 3.3 Rest of the Modeling Domain................................................................................. 10 4. Estimation of Emission Factors and Composite Emission Factors for Wildfires......... 12 4.1 Overview of Approach............................................................................................ 12 4.2 Estimation of Emission Factors .............................................................................. 12 4.3 Calculation of Composite Emission Factors for the State of Texas ....................... 13 4.4 Calculation of Composite Emission Factors for the Rest of the Modeling Domain ....................................................................................................................................... 14 4.4.1 Use of FOFEM Emission Factors and NFDRS Fuel Loading Factors ............ 14 4.4.2 Spatial Correlation of NFDRS and FOFEM Fuel Models............................... 15 5. Results........................................................................................................................... 16 5.1 Overview................................................................................................................. 16 5.2 Total Acreage Burned in Texas in 2000 ................................................................. 17 5.3 Total Acreage Burned in Texas during August to September, 2000 ...................... 17 5.4 Total Wildfire Acreage Burned in HGBPA Subdomain......................................... 17 5.5 Wildfire Emissions in HGBPA Subdomain............................................................ 18 5.6 Observational Evidence: TEOM Results ................................................................ 21 6. Preparation of a CAMx-Ready Input File..................................................................... 24 6.1 Overview................................................................................................................. 24 6.2 AFS File .................................................................................................................. 24 6.3 Chemical Speciation of NMHCs ............................................................................ 24 6.4 Calculating fire plume rise...................................................................................... 27 6.4.1 Existing Plume Rise Models............................................................................ 28 6.4.1.1 FIREPLUME model ................................................................................. 28 6.4.1.2 CALPUFF Model ..................................................................................... 30 6.4.1.3 Obtaining Input Data................................................................................. 32 6.4.2 Using Models ................................................................................................... 35 6.4.2.1 FIREPLUME Results................................................................................ 36 6.4.2.2 CALPUFF Calculations ............................................................................ 40 6.4.2.3 Comparison between FIREPLUME and CALPUFF results..................... 43 6.4.2.4 Conclusions and Recommendations ......................................................... 44 7. References..................................................................................................................... 45 iii Appendix A: Land Cover Code Descriptions ................................................................... 47 Appendix B: Daily Plots of Fires and 32-Hour Wind Back-Trajectories........................ 49 Appendix B-1: Daily Plots of Fires onto the LULC Map............................................ 49 Appendix B-2: Daily Plots of Fires and 32-Hour Wind Back-Trajectories............... 112 Appendix C: Contact Summary ...................................................................................... 172 iv List of Tables Table 1: Fuel consumption values (ton/acre) assigned to fuel categories and wildland cover types. ................................................................................................................. 9 Table 2: Dead fuel categories as the time scale at which moisture content varies and by diameter (Dennis, 2000).............................................................................................. 9 Table 3: Fuel loading values (ton/acre) assigned to fuel categories and vegetation cover types in the NFDRS. ................................................................................................. 11 Table 4: Relationship between NFDRS and FOFEM fuel categories. ............................. 12 Table 5: Emission factors (EFs) (lb/ton) for wildfire burns. These factors were calculated under dry conditions for each fuel component using combustion efficiency information from FOFEM 4.0 and EF algorithms developed by Ward et al. (1993). EFs for NOX and NH3 were calculated with relations by Dignon and Penner (1991) and Yokelson et al. (1997). ....................................................................................... 13 Table 6: Composite emission factors (CEFs) (lb/acre) assigned to wildland cover types. CEFs were calculated from the dry conditions and emission efficiencies given by the FOFEM program and FOFEM fuel consumption values (Tables 1 and 5). ............. 14 Table 7: Calculated composite emission factors (lb/acre) assigned to wildland cover types for the domain excluding Texas. The emission factors were calculated from the dry conditions and emission efficiencies given by the FOFEM program and NFDRS fuel loading values (Table 3)............................................................................................ 15 Table 8: Mass Percents (%) of Total gaseous NMHC of different chemical species in Loblolly pine............................................................................................................. 25 Table 9: CB-IV Speciation Profile for NMHCs .............................................................. 27 Table 10: Input Data for FIREPLUME and CALPUFF Models ...................................... 32 Table 11: Access database of selected Forest Fires .......................................................... 35 Table A- 1: Description of FOFEM land cover codes..................................................... 47 Table A- 2: Description of NFDRS LULC codes............................................................. 48 Table B- 1: Description of land use categories and associated composite emission factors for PM2.5, NOX, and NMHC. .................................................................................... 50 Table C- 1: Contact Information..................................................................................... 172 v List of Figures Figure 1: Details of CAMx Modeling Domain for the Houston-Galveston modeling episode, August 25 – September 1, 2000. Regional Domain (dark blue), East Texas Subdomain (green) HGBPA Subdomain (red), and HG Subdomain (light blue)....... 2 Figure 2: Acreage burned in different types of fires in Texas in August – September 2000........................................................................................................................... 17 Figure 3: Acres burned in wildfires in the HGBPA subdomain. During August – September, 2000. ...................................................................................................... 18 Figure 4: Emissions of CO, NMHC, PM2.5, and NOX from fires in the HGBPA Subdomain during August – September, 2000. ........................................................ 20 Figure 5: Comparison of LDGV emissions of VOC and NOX in the 8-county HG area (first four columns) with wildfire emissions of NMHC and NOX in the HGBPA domain (last four columns). ...................................................................................... 20 Figure 6: Details of TEOM Domain (black line), TEOM monitors (colored points), and HGBPA Subdomain (red line). ................................................................................. 21 Figure 7: Time series of TEOM monitors PM2.5 measurements for August 22 September 7, 2000. ................................................................................................... 22 Figure 8: (a) Interpolated TEOM monitor data of PM2.5 concentrations for September 4, 2000 at 5:00 p.m. within the TEOM Domain. (b) Fires (red points) and 32-hour wind-back trajectories starting at 5:00 p.m. for September 4, 2000. The different back-trajectory colors represent the wind’s height above the ground at the starting point (La Porte): green: 10 meters above ground, brown: 500 m, blue: 1000 m. However, thorough wind mixing occurred on that day, so that, except at the starting point, the different wind trajectories cannot be allocated onto a vertical layer. ....... 23 Figure 9: Plume rise calculations with velocity data of different CAMx layers ............. 37 Figure 10: Plume rise with vertical CAMx structure (with wind velocity-layer 3)......... 38 Figure 11: Plume rise of fire ID 1033 and wind velocity on Aug 30, 2000 .................... 39 Figure 12: Plume rise calculations with different fire temperatures. Fire ID 1033, 1085, and 1094 are the fire events occurred in Aug 30, Aug 31, and Sep 1, respectively. 41 Figure 13: CALPUFF Plume rise calculations with CAMx vertical layers..................... 42 Figure 14 (a) Plume rise for low wind day showing a gradual change during the day; (b) Plume rise on a near neutral atmospheric stability in the afternoon. .................. 43 Figure B- 1: Legend. The red dots indicate the size of the fire. The colors correspond to vegetation cover codes. Table B-1 contains the description of the cover codes...... 49 Figure B- 2: Legend. The values in meters (green, brown, and blue dots) correspond to the height above the ground of the wind trajectory at the starting hour (La Porte site). The dots in red correspond to different fire sizes.......................................... 112 vi 1. Introduction Outdoor fires, including wildfires, prescribed rangeland burns, slash burns, and agricultural field burns, can emit substantial amounts of particulate matter, carbon monoxide, hydrocarbons, nitrogen oxides, and ammonia into the atmosphere. The purpose of this project is to calculate the magnitude of emissions and the spatial and temporal distribution of emissions from outdoor fires for the period of the Texas Air Quality Study (TexAQS), August 1 to September 30, 2000. Emissions were estimated over the Super-COAST (Coastal Oxidant Assessment for Southeast Texas) CAMx (Comprehensive Air Quality Model with Extensions) Regional Domain, as well as for the Houston/Galveston-Beaumont/Port Arthur (HGBPA) Subdomain, which is embedded in the Super-Coast domain. The modeling domain is shown in Figure 1. The data required to calculate emissions of CO, CO2, CH4, non-methane hydrocarbons (NMHC), particulate matter (PM), PM less than 2.5 micrometers in diameter (PM2.5), PM less than 10 micrometers in diameter (PM10), ammonia (NH3), and nitrogen oxides (NOX) are as follows: • The acreage burned (acres/day) • The location and duration of the fire • The fuel consumption factors of the burned vegetation (tons/acre) • The emission factors for each pollutant and fuel type (lbs/ton), and • The emission efficiency (unitless). The methods used to estimate acreage burned, fire location and duration, fuel loadings, and emission factors are described in the next three sections. The final sections of the report describe the results and methods used to develop CAMx input files. 1 The CAMx modeling domain is defined with the Lambert Conformal Conic map projection: First True Latitude (Alpha) 30°N Second True Latitude (Beta) 60°N Central Longitude (Gamma) 100°W Projection Origin (100°W, 40°N) Spheroid Perfect Sphere, Radius = 3670 km Domain Name Regional Domain East Texas Subdomain HGBPA Subdomain HG Subdomain Range (km) Easting (-108,1512) (-12,1056) (356,688) (431,505) Northing (-1584,72) (-1488,-420) (-1228,-968) (-1153,-1079) Number of Cells Cell Size (km) Easting Northing Easting Northing 45 89 83 74 46 89 65 74 36 12 4 1 36 12 4 1 Figure 1: Details of CAMx Modeling Domain for the Houston-Galveston modeling episode, August 25 – September 1, 2000. Regional Domain (dark blue), East Texas Subdomain (green) HGBPA Subdomain (red), and HG Subdomain (light blue). 2 2. Collection and Assembly of Fire History Data 2.1 Overview of Approach To create a spatially and temporally resolved inventory of outdoor fire emissions over the Super-COAST CAMx modeling domain, data on fire location and burned acreage were collected from several data sources for each fire, on a daily basis for the period of August 1, 2000-September 30, 2000. The data sources for wildfire activity data include the National Interagency Fire Management Integrated Database (NIFMID), the Texas Interagency Coordination Center (TICC), the Louisiana Interagency Coordination Center, the United States Department of Agriculture (USDA) Forest Service, and the Oklahoma Department of Agriculture, Food and Forestry. After contacting several agencies, it was found that there are no reliable data sources for prescribed rangeland, slash, and agricultural burns. Thus, data for this type of fire will be extracted from the work of Dennis (2000). 2.2 Wildfires Due to the number and extent of wildfires during the summer of 2000, the collection of wildfire data was the most difficult and important task in this inventory development. Wildfire activity data were collected for the period of August 1, 2000 – September 30, 2000 over the Super-COAST CAMx modeling domain from the following data sources: a) National Interagency Fire Management Integrated Database (NIFMID): This database is maintained by the National Interagency Coordination Center (NICC) and captures information pertaining to large wildfire incidents (i.e., more than 100 acres in timber or more than 300 acres in grass/shrub fuel types) occurring on federal and private ownership lands. Several state forest departments and federal agencies, including the United States Department of Agriculture (USDA) Forest Service, the Fish & Wildlife Service (FWS), the National Park Service (NPS), the Bureau of Land Management (BLM), the Bureau of Indian Affairs (BIA), and the Department of Defense (DOD), report fire incident information to the NICC. NIFMID information for the period of interest was downloaded in a MS Access format from http://famweb.nwcg.gov. Most of the wildfire records include information on fire location in latitude/longitude coordinates, the date on which the fire occurred, the burned area in acres, the fire incident name, and the type of vegetation burned. The fire records with missing latitude/longitude coordinates included information on the closest city to the fire location. b) Texas Interagency Coordination Center (TICC): In the TICC, a Texas Forest Service (TFS) representative maintains the wildfire records for state and private lands and a USDA Forest Service representative maintains the wildfire records for federal ownership lands. The records of wildfires that occurred on state, private and federal ownership lands were obtained in spreadsheet formats. Most of the wildfire records include information on the fire location, the date on which fire occurred, the burned area in acres, the fire incident name, the date on which the fire was controlled, and the name of the 3 county where the fire was located. In this database, the fire location was reported in the TFS Block & Grid format for wildfires in East Texas and the county in which the fire had occurred was reported for the fires in West Texas. The location of the fires in East Texas was converted to latitude/lomgitude coordinates using TFS conversion software and a TFS Block & Grid Map. c) Louisiana Interagency Coordination Center: The records of wildfires that occurred on Kisatchie National Forest lands (federal ownership) in Louisiana were obtained from this agency. Information on other federal lands was not available. The records include information on the fire location in Township/Range/Section format, the date on which fire occurred, the burned area in acres, and the district information. The fire location data were manually converted to latitude/longitude coordinates using hard copy maps of Louisiana with Township/Range and latitude/longitude coordinates. d) USDA Forest Service: The records of wildfires that occurred on federal ownership lands in the United States for the year 2000 were obtained from the USDA Forest Service. The records include information on the fire location in latitude/longitude coordinates, the date on which the fire occurred, the burned acreage in acres, the type of vegetation burned, and the state in which the fire occurred. e) Oklahoma Department of Agriculture, Food & Forestry: The records of wildfires that occurred on state and private lands in the state of Oklahoma were obtained. The records include information on the fire location in Township/Range/Section format, the date on which fire occurred, the burned area in acres, the type of vegetation burned, and the county in which the fire occurred. The fire location data in Township/Range/Section format were converted to latitude/longitude coordinates using TRS2LL version 11/26/2001. This program was downloaded from http://www.esg.montana.edu/gl/trsdata.html and converts between Township/Range/Section data and latitude/longitude coordinates. At present this program covers 17 states (AR, AZ, CA, CO, ID, KS, MT, ND, NE, NM, NV, OK, OR, SD, UT, WA and WY). All the fire records in the above data sources were integrated into a single database in spreadsheet format and duplicated fires were identified through common parameters, such as the fire incident name, the fire location, and the reporting agency. Most of the duplicate fire records in NIFMID and TFS databases were identified with the fire incident name. Only fires greater than 10 acres were analyzed for duplications in this study, since most of the smaller fires lacked complete information and common parameters in the databases. It was assumed that the duplicated fires under 10 acres would not add significantly to the error in the calculation of emissions. The databases used in this study have varying degrees of completeness. The most complete databases were the TFS database, the NIFMID, and USDA Forest Service database. In the TFS database, fire records include additional information on the duration of the burning. For the fires with this information, the burned acreage was uniformly distributed over the duration of burning. The USDA Forest Service database reports wildfire incidents occurring on federal ownership lands in all the states in the Super- 4 COAST CAMx modeling domain. The NIFMID database is a complete database for the large wildfire incidents occurring on federal and private ownership lands in all the states of the Regional Domain. The least complete database was collected from the Oklahoma Dept. of Agriculture, Food & Forestry. This database provides the records for wildfire incidents occurring in eastern Oklahoma private ownership lands only. 2.3 Agricultural, Prescribed Range, and Slash Burning Agricultural, prescribed range, and slash burns were found not to contribute substantially to emissions and thus they were not used in the final fire inventory and emissions calculations. Detailed below is a description of how the acreage burned was estimated for these types of fires. 2.3.1 Agricultural Burns County agricultural extension agents, TNRCC field investigators and the Texas Dept. of Agriculture were surveyed by phone to determine the extent to which crop residue burning is currently practiced in Texas. Questions about the extent and frequency of cropland burning were included in an email survey of 58 randomly selected Agricultural Extension Agents representative of the 12 Extension Districts of Texas. The response rate to the survey was only 14%; however, the responses were consistent. Responses indicated that very little (<5%) of cropland is commonly burned after harvest and that the practice was probably more rare in the August/September 2000 period due to drought conditions. Responses also indicated that, regardless of weather conditions, burning of crop residues is losing favor among farmers because crop residues aid moisture retention in soils. One agricultural extension agent noted that crop residue is only burned in his area when the residue is excessively dense; this is not a condition that occurs in drought season like summer 2000. No reporting of this type of burn is required and no records of such burns were found. Responses to surveys and phone calls were consistent with previous findings (Dennis, 2000) about the extent of cropland burning activities in 1996-1997. Some Agricultural Extension Agents indicated that the practice has become less common in the last decade, but all of these statements were anecdotal. No agents indicated that burning crop residue is becoming more common or favored among farmers. Dennis (2000) produced estimations of emissions from cropland burning by using reports from local officials, known crop distributions, and fuel loading factors. The results of these calculations are emissions values for each county on a monthly basis. Though the estimates are not point specific or date specific, they may represent the best resolution currently possible given the paucity of specific records and they were used this in this study to predict emissions from these types of fires. Though anecdotal reports suggest that cropland burning is gradually declining, there is not enough information to assign a value to this trend. 5 2.3.2 Prescribed Range Burning Researchers associated with Texas A&M University who study prescribed rangeland burns were contacted concerning the extent of the practice of burning rangelands. Dr. Butch Taylor, of the TAMU Agricultural Research Station Sonora, who leads the Edwards Plateau Prescribed Burning Association, reports that, though there is increasing interest in the practice, drought conditions have made it unfeasible for the past few years. He also indicated that much of the increased interest in prescribed burning has been in Central Texas, where fire is used to control Ashe Juniper (cedar) populations. Conversations with Dr. Taylor and Donnie Frels of the Kerr Wildlife Management Area (which researches prescribed burning of rangeland) indicate that hot summer burns that could have impact on the TexAQS data should not be performed in conditions like those in August and September of 2000. These statements are consistent with published rangeland burning practices found at http://www.rw.ttu.edu/fec/burnweather.htm and http://texnat.tamu.edu/ranchref/guide/rwabc.htm. Questions about the extent and frequency of rangeland burning were included in an email survey of 58 randomly selected Agricultural Extension Agents representative of the 12 Extension Districts of Texas. The response rate to the survey was only 14%; however, the responses about frequency and extent of rangeland burning were consistent with statements by Dr.Taylor and Mr. Frels. The only finding in this survey that was not included in Dennis (2000) is that coastal marsh grasses are sometimes burned to increase the palatable grasses for cattle. According to Kelly Boult, Agricultural Extension Agent for Jefferson Co., the marsh grasses that are burned this way grow within 15 miles of the coast. Local agricultural extension agents report that the practice usually takes place in winter and that the practice is uncommon; however, since ranchers are not required to report these fires, no records are available for burning of coastal marsh grasses. Dennis (2000) produced estimations of emissions from rangeland burning in the same way that she estimated cropland burning, by using reports from local officials, known land use patterns and fuel loading factors. The results of these calculations are emissions values for each county on a monthly basis. Though the estimates are not point specific or date specific, they may represent the best resolution currently possible given the paucity of specific records and they were used this in this study to predict emissions from these types of fires. Though anecdotal reports suggest that rangeland burning is becoming a more popular method the same reports indicate that, during TexAQS, prescribed rangeland burning would have been minimal due to unfavorable meteorological conditions. There was not enough information to support any modification of the emission values in Dennis (2000). 2.3.3 Slash Burning In Texas, two types of slash burning activities were identified by Dennis (2000) as sources of outdoor burning emissions: residue of logging operations burned as part of site preparation processes, and burning of debris from land clearing operations. Dennis’ 6 (2000) procedure to estimate the burned acreage was followed in this study and is outlined below. 2.3.3.1 Logging debris Dennis (2000) estimated the burned acreage of logging residues from information on the total industrial harvest volume (in cubic feet) in the year of interest (published by the Harvest Trends Report, an annual TFS publication). Dennis (2000) also assumed that all counties experienced the most intense harvesting reported by the Harvest Trends Report, 80 cubic feet per acre. The total harvest volume in 2000 was 728,500,000 cubic feet (Texas Forest Service, 2000), which implies that over 9.1 million acres were harvested. 2.3.3.2 Land Clearing Debris The state of Texas has no record keeping system for the burning of land clearing debris. Dennis (2000) calculated a first estimate of the acres cleared in land clearing operations by multiplying the fraction of population growth by the acres of urban area. Dennis (2000) used the composite database created by Wiedinmyer et al. (2000) to estimate the total urban area in each county, which totaled 2,677,124 acres distributed in 75 counties. Census data for 1999 (US Census Bureau, 2000) and 2000 populations (US Census Bureau, 2001) by county were assembled for this study. Applying the growth fractions to the urban area of each county, an estimated total of 231,230 acres were cleared in 2000 from the 75 counties. An estimated 10 percent of the cleared acres were burned (Dennis, 2000), totaling 23,123 acres burned in land clearing activities. This number is not listed in the results section, since slash burns were deemed negligible and there is a high uncertainty associated with the calculations. 3. Estimation of Fuel Loading and Consumption Factors for Wildfires Fuel loading values (ton/acre) refer to the tons of fuel available for combustion per acre, and the fuel consumption factors (ton/acre) represent the tons of fuel that are actually combusted in a fire. The vegetation comprising the total fuel available to a fire is made of several components, generally broken down into dead woody fuels, live fuels, duff, and litter, and dead fuel is subcategorized based on the diameter of the wood. Fuel loading and consumption factors were broken down into these categories for each vegetation type. 3.1 Overview of Approach Fuel consumption factors for prescribed range burns and slash burns are not included in the report, since emissions from these types of fires were assumed to be negligible. Fuel loading and consumption values for wildfires were based on the First Order Fire Effects Model version 4.0 (FOFEM 4.0) default values for wildfires in Texas. For the domain outside of Texas, the National Fire Danger Ranting System (NFDRS) database was used 7 to spatially allocate fuel loading factors (fuel consumption factors are not available within this database). Fuel consumption values (tons of fuel per acre) were spatially allocated within the modeling domain. A Geographic Information System (GIS) framework was used to record and manipulate the data; ArcInfo 8.1, and ArcView 3.2a were used. 3.2 State of Texas FOFEM 4.0 contains default fuel consumption factors for vegetation cover codes in the contiguous United States, but it does not include information on the spatial distribution of these cover types. Dennis (2000) selected 15 vegetation cover codes, corresponding to vegetation types in the Regional Domain, and cross-referenced them with vegetation types allocated onto a database of the state of Texas developed by Wiedinmyer et al. (2000). As a result, a composite land use-land cover (LULC) database with spatial FOFEM cover types was created for Texas. Dennis (2000) modified the fuel consumption factors associated with the cover codes where additional information was available. The fuel consumption factors were then spatially allocated onto the LULC database with ArcInfo. The fuel consumption factors in FOFEM are broken down into fuel categories. Ward et al. (1993) gave a general definition of fuel categories: • Dead woody fuels: include branches, logs, stumps, and limbs. These fuels are broken down into sub-categories based on diameter: wood 0-1’’, wood 1-3’’, and wood 3+’’. • Live fuels: include grass, low, shrubs, ferns, seedling, and other small herbaceous plants. • Duff: matted layers of partially decomposed organic matter and high organic content soils such as humus or peat. • Litter: fallen leaves and needles, twigs, bark, cones, and small branches that have not decayed to the extent of loosing their identity. The FOFEM fuel categories are as follows: • Litter • Wood 0-1’’, wood 1-3’’, and wood 3+’’ • Herb • Shrub • Duff • Canopy fuels. Table 1 shows the fuel consumption values assigned to FOFEM 4.0 vegetation cover types, and broken down into fuel categories. A description of the vegetation cover types can be found in Table A-1 of the Appendix. 8 Table 1: Fuel consumption values (ton/acre) assigned to fuel categories and wildland cover types. Cover Code Litter Wood 0-1’’ Consumption Factor (ton/acre) Wood Wood Herb Shrub Duff 1-3’’ 3+’’ Canopy Fuels Total 0 1 2 0.3 0.3 3 6 7 18 21 22 23 100a 147a 147b 147c 151a 211 293 999 0.6 2.4 4.5 0.4 0.1 0.1 1.0 0.6 0.6 2.4 4.5 2.2 2.0 3.1 5.2 0.6 4.7 6.3 3.0 6.6 9.8 6.7 0 0.1 0.1 0.1 0.1 0.5 0.6 0.5 0.7 2.0 1.4 1.0 0.5 0.6 1.7 1.8 2.9 3.7 1.3 1.7 0.5 0.4 2.5 3.3 2.0 0.1 0.2 0.2 4.2 1.0 0.2 0.8 4.0 2.6 4.7 0.1 Source: Dennis (2000) The 15 cover codes assigned by Dennis (2000) to the composite LULC database are characterized by different numbers and are not broken down into further subcategories, as in FOFEM 4.0 (i.e., only 147 exists, not 147a, b, c); in this study, fuel consumption factors for 147a were assigned to the code 147. Table 2 shows two different ways of measuring the fuel diameter. The time scale reported in Table 2 is an historical definition and it represents the length of time that it takes for the fuel to respond to within 63.2% of a new equilibrium moisture content during drying or wetting processes. Larger diameter fuels have longer time lags, because they respond more slowly to changes in environmental conditions. Table 2: Dead fuel categories as the time scale at which moisture content varies and by diameter (Dennis, 2000). Time Scale 1 hr 10 hr 100 hr 1000 hr Fuel Diameter 0 – 0.25’’ 0.25 – 1’’ 1 – 3’’ 3 – 6’’ Source: Dennis (2000) 9 3.3 Rest of the Modeling Domain The rest of the modeling domain was assigned fuel loading factors based on NFDRS fuel models. The NFDRS was developed as a method to rate wildfire danger by the USDA Forest Service. The NFDRS fuel models have several disadvantages relative to the FOFEM fuel models: the fuel categories do not include canopy, duff, or litter loadings, and only fuel loading values (not fuel consumption values) are included in the model, whereas, consumption equations are embedded in FOFEM. Although FOFEM 4.0 and the newer version 5.0 contain vegetation cover types and fuel consumption values for the contiguous United States, the spatial allocation of these vegetation types –such as the cross-referencing work of Dennis (2000) done for the State of Texas– was outside the scope of this project. Therefore, the readily available, spatially allocated NFDRS fuel models were used for the domain outside of Texas. For this purpose, the file nfdrfuel.asc was downloaded by anonymous ftp from ftp://www.fs.fed.us/pub/wfas/fuels and imported into ArcInfo. The file assigns 24 different vegetation cover types to the contiguous United States. The modeling domain was clipped out, and fuel loading values corresponding to each cover type (Burgan, 1988) were projected onto the file with ArcInfo and ArcView. NFDRS fuel models do not include fuel loading values for agricultural lands. In the NFDRS models, fuel is broken down into the following categories: • 1 hr • 10 hr • 100 hr • 1000 hr • Woody • Herbaceous • Drought The drought fuel category accounts for the deep drying of litter and duff. As deep drying occurs, it is assumed that more fuel becomes available for consumption within the flaming front of a fire (Burgan, 1988). Table 3 lists the NFDRS fuel loading factors broken down into fuel categories and vegetation cover types. A description of the vegetation cover types can be found in Table A-2 of the Appendix. A relationship between the NFDRS fuel categories and the FOFEM fuel categories will be necessary for the estimation of emission factors outside Texas. Hardy et al. (1996) related the NFDRS fuel categories (except drought and canopy fuels) with the FOFEM fuel categories. The NFDRS drought fuel category was set equivalent to the duff fuel category with a “very dry” moisture option in FOFEM, since the drought fuel category accounts for the deep drying of litter and duff (Burgan, 1988). The NFDRS does not account for the burning of canopy fuels. Hardy et al. (1996) did not establish a relationship between the FOFEM fuel categories litter, duff, shrubs, and regen and the NFDRS fuel categories. In this study, litter and wood 0 – 1’’ were assumed to be 10 equivalent, and shrubs and herbs were assumed to be equivalent. Table 4 summarizes these relationships. Table 3: Fuel loading values (ton/acre) assigned to fuel categories and vegetation cover types in the NFDRS. Vegetation code Fuel Load (ton/acre) Total 1hr 10hr 100hr 1000hr Woody 0 0 1 0.7 2 23 3 4.8 4 8.5 5 4.75 6 16.5 7 27.5 8 9.5 9 58 10 32.5 11 12 12 1 13 0 14 7 15 20.5 16 4.5 17 19.3 18 3 19 4.5 20 5.5 21 7 22 0 23 0 24 0 Source: Burgan (1988) 0 0.2 3.5 0.4 2 1 2.5 2.5 1.5 12 7 2.5 0.25 0 1.5 2 1 2.5 0.5 0.5 1 1.5 0 0 0 0 0 4 1 1 0.5 2 2 1 12 7 2.5 0 0 1.5 3 1 5.4 0.5 0.5 0.5 1.5 0 0 0 0 0 0.5 0 0 0.25 1.5 5 2 10 6 2 0 0 0 3 0.5 2.9 0.5 0.5 0 1 0 0 0 0 0 0 0 0 0 0 12 2 12 5.5 2.5 0 0 0 2 0 1 0 0.5 0 0 0 0 0 0 0 11.5 0.8 3 1 7 0.5 0.5 0 0 0 0 0 2 7 0.5 3 0.5 0.5 2.5 0.5 0 0 0 11 Herba ceous 0 0.3 0 0.8 1 0.5 1 0.5 0.5 0 0 0 0.5 0 0 0 0.5 1 0.5 0.5 0.5 0.5 0 0 0 Drought 0 0.2 3.5 1.8 1.5 1.5 2.5 5 2 12 7 2.5 0.25 0 2 3.5 1 3.5 0.5 1.5 1 2 0 0 0 Table 4: Relationship between NFDRS and FOFEM fuel categories. Fuel Component Model Litter 1 hr (0 – 0.25’’) 10 hr (0.25 – 1’’) 100 hr (1 – 3’’) 1000 hr (3 – 9’’) Woody (9+’’) Duff Herbs Shrubs Regen. Canopy NFDRS 1 hr 1 hr 10 hr 100 hr 1000 hr Woody --Herbaceous Herbaceous ----- Drought Drought FOFEM Litter Wood 0 – 1’’ Wood 0 – 1’’ Wood 1 – 3’’ Wood 3+’’ Wood 3+’’ Duff Herbs Shrubs Regen Canopy Duff (“very dry” moisture option) 4. Estimation of Emission Factors and Composite Emission Factors for Wildfires 4.1 Overview of Approach Emission factors (lb/ton) represent the pounds of pollutant emitted per ton of burned fuel. Emission factors for wildfires are based on combustion efficiency algorithms and fuel components, and were estimated with the assistance of the computer model FOFEM 4.0. Composite emission factors (lb/acre) reflect the pounds of pollutant emitted per area burned. 4.2 Estimation of Emission Factors FOFEM 4.0 was selected to assist in the determination of emission factors and efficiencies for wildfire. Emission factors were calculated with algorithms developed by Ward et al. (1993) for PM, PM2.5, PM10, CO, CH4, and NMHC, which required the use of combustion efficiencies. Combustion efficiencies are defined in FOFEM for six fuel categories (wood 0-1’’, wood 1-3’’, wood 3+’’, herb and shrub, duff, and canopy fuel), four different fuel moistures (very dry, dry, moderate, and wet), and different stages of the fire (flaming and smoldering). The default ‘dry’ fuel moisture was selected for all calculations, and the efficiencies for the flaming and smoldering phase were averaged. Emission factors were then calculated for each fuel category and pollutant. To calculate the NOX emission factor, its relationship with percent fuel nitrogen was used (Clements and McMahon, 1980; as referenced by Dignon and Penner, 1991), where 70 was the percent fuel nitrogen. A molar ratio of NH3 to NOX was used to calculate the NH3 emission factor (Yokelson et al., 1997). This procedure is outlined with more detail in Dennis (2000). The emission factors are listed in Table 5. 12 Emission factors were then spatially allocated onto the modeling domain. This was done by calculating composite emission factors in lb/acre for each vegetation cover type and fuel category. Composite emission factors have different units from emission factors and need only be multiplied by the area of a fire to obtain emissions in lbs. Table 5: Emission factors (EFs) (lb/ton) for wildfire burns. These factors were calculated under dry conditions for each fuel component using combustion efficiency information from FOFEM 4.0 and EF algorithms developed by Ward et al. (1993). EFs for NOX and NH3 were calculated with relations by Dignon and Penner (1991) and Yokelson et al. (1997). Average Fuel Combustion Component Efficiency Wood 00.95 1’’ Wood 10.92 3’’ Wood 3+’’ 0.89 Herb and 0.85 Shrub Emission factors (lb/ton) CO CH4 NMHC PM PM2.5 PM10 NOX NH3 52 3 6 15 8 9 2.5 0.5 111 6 9 20 12 14 2.5 1.1 174 9 12 26 16 19 2.5 1.7 249 12 16 33 21 25 2.5 2.6 Duff 0.82 316 15 20 39 26 30 2.5 3.2 Canopy Fuels 0.85 249 12 16 33 21 25 2.5 2.6 Source: Dennis (2000) 4.3 Calculation of Composite Emission Factors for the State of Texas For each pollutant and vegetation cover type, composite emission factors were obtained by multiplying the emission factors of the pollutant broken down into fuel categories by the fuel consumption factors of the vegetation cover type, which are broken down into the same fuel categories. The calculation is shown in the example below and Table 6 shows the results. The composite emission factors were then allocated spatially onto the state of Texas. Example: Calculation of a composite emission factor (CEF) for the land cover type 2 and the pollutant CO (see Table 1 for the fuel loading in ton per acre for land cover 2, and Table 5 for the emission factors in lb/ton): CEF = (52 lb/ton)×(0 ton/acre) + (111 lb/ton) × (0 ton/acre) + (174 lb/ton) × (0 ton/acre) + (249 lb/ton) × (0.3 ton/acre) + (316 lb/ton) × (0 ton/acre) + (249 lb/ton) ×(0 ton/acre) = 74.7 lb/ton ≈ 75 lb/acre. Since the LULC GIS vegetation database created by Dennis (2000) does not include appendices “a”, “b”, “c”, or “d” in the cover codes, the cover code 147 in the database was assigned the composite emission factors of 147a in Table 6. 13 Table 6: Composite emission factors (CEFs) (lb/acre) assigned to wildland cover types. CEFs were calculated from the dry conditions and emission efficiencies given by the FOFEM program and FOFEM fuel consumption values (Tables 1 and 5). Code 1 2 3 6 7 18 21 22 23 100a 147a 147b 147c 151a 211 293 999 CO 0 75 157 586 1121 534 481 753 1299 157 1033 1378 748 1389 1803 1750 0 CH4 0 4 8 28 54 26 23 36 62 8 50 67 36 68 89 84 0 Composite Emission Factor (lb/acre) NMHC PM PM10 PM2.5 0 0 0 0 5 10 8 6 10 21 16 13 38 77 59 50 73 147 113 96 35 71 54 46 32 64 49 41 49 100 76 65 85 170 131 111 10 21 16 13 69 141 107 90 92 188 142 121 49 98 75 64 93 193 145 123 125 262 194 165 113 227 174 148 0 0 0 0 NOX 0 0.7 1.5 5.8 11.1 5.5 4.9 7.6 12.8 1.5 11.6 15 7 16.2 23.9 16.5 0 NH3 0 0.3 0.6 2.2 4.2 2.1 1.9 2.9 4.8 0.6 4.4 14 8 6.2 9.3 6.2 0 4.4 Calculation of Composite Emission Factors for the Rest of the Modeling Domain Two methods were devised to allocate emission factors spatially onto the rest of the modeling domain. 4.4.1 Use of FOFEM Emission Factors and NFDRS Fuel Loading Factors NFDRS fuel loading factors and emission factors, broken down into fuel categories, were used to calculate the new emission factors for each NFDRS vegetation type. The NFDRS and FOFEM fuel categories were correlated as outlined in Table 4 to assign the emission factors calculated with the FOFEM program (Table 5) to the fuel subcategories in the NFDRS. The results are shown in Table 7. The values were calculated as outlined in the example above. A drawback of this method resides in the failure of the NFDRS fuel models to account for fuel consumption equations and canopy, duff, or litter fuel components. Yet, the NFDRS fuel models include high fuel loadings for the drought fuel component, which has a compensating effect. A source of uncertainty associated with this method is the error underlying the relationship established between the fuel types in FOFEM and in the NFDRS (Table 4). 14 Table 7: Calculated composite emission factors (lb/acre) assigned to wildland cover types for the domain excluding Texas. The emission factors were calculated from the dry conditions and emission efficiencies given by the FOFEM program and NFDRS fuel loading values (Table 3). Code 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 CO 0 148.3 3552.5 980 1401 878.25 2657.5 4668.5 1543.5 8238 4563 1707 216.5 0 1136 3265 687 2783.7 477 880 953.5 1110.5 0 0 0 CH4 0 7.2 181.5 48 70.5 43.5 135 237 78 420 232.5 87 10.5 0 57 166.5 34.5 141.6 24 43.5 48 55.5 0 0 0 Composite Emission Factor (lb/acre) NMHC PM PM2.5 PM10 0 0 0 0 10 20.7 13.1 15.3 257.5 558 341 398 66.8 138.4 87.6 101.8 100 214.5 132 154 61.25 128.5 80.5 93.5 190.5 410 252 294.5 330 704 436.5 510.5 111 237 146.5 170.5 618 1340 816 944 344 746 454 524.5 128 277.5 169 195.5 14.5 30 19 22.25 0 0 0 0 82 175 108 125 235 505.5 311 363 50.5 108.5 66.5 77 207.5 450 274 317.7 34.5 74 45.5 53 60.5 126 79.5 92.5 67 143 88.5 103.5 81 172.5 106.5 123 0 0 0 0 0 0 0 0 0 0 0 0 NOX 0 1.75 57.5 12 21.25 11.875 41.25 68.75 23.75 145 81.25 30 2.5 0 17.5 51.25 11.25 48.25 7.5 11.25 13.75 17.5 0 0 0 NH3 0 1.52 35.05 9.9 14 8.825 26.4 46.3 15.4 81.8 45.35 16.95 2.225 0 11.3 32.3 6.9 27.74 4.8 8.85 9.5 11.15 0 0 0 4.4.2 Spatial Correlation of NFDRS and FOFEM Fuel Models The LULC fuel model map created by Dennis (2000) and the NFDRS fuel model map were superimposed and the vegetation cover codes in Texas were correlated with the NFRDS categories. In principle, if NFRDS categories could be assigned to the land covers used by Dennis, the land covers could then, in turn, be related to FOFEM categories. Unfortunately, this method is rather inaccurate, since species are agglomerated differently in both databases and thus the NFDRS and the FOFEM 4.0 cover codes cannot be easily related. For instance, in attempting to build correlations, the NFDRS cover codes 22, 23, and 24 were assigned composite emission factors greater than zero, even though they represent land covers that do not emit pollutants when burned or cannot get burned (i.e., water, barren). This illustrates the uncertainty associated with this methodology. Furthermore, the NFDRS cover code 15 is not present in Texas, but exists in the South of Louisiana; an emission factor for this cover code would need to be calculated by making an educated guess. 15 After reviewing the two methods outlined above, the former, consisting of calculating composite emission factors for each NFDRS cover code, was chosen, since the uncertainty associated with it is most likely smaller than the uncertainty associated with the latter method. Table B-1 in the Appendix shows the land cover codes used in the modeling domain (FOFEM for Texas and NFDRS for the domain that excludes Texas) and the composite emission factors for PM2.5, NOX, and NMHC for each land cover type. 5. Results Plots of fire locations for August and September 2000 are attached in Appendix B-1. The fires are plotted onto the land use/land cover map of the modeling domain, each color representing a different land use type. Presented in the Appendix B-2 are fire locations and wind back-trajectory plots for the same days. The wind back trajectories were computed for each day in the months of August and September 2000 using the HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model available at http://www.arl.noaa.gov/ready/hysplit4.html and the Trajectory Analysis for TexAQS2000 model available from the Air Quality Modeling group at the University of Houston (http://www.uh.edu/aqm/). The University of Houston trajectories were used whenever they were available (for the dates of August 22 – September 01) since they are based on a richer observational data set. The HYSPLIT data were used for all other dates. The EDAS (Eta Data Assimilation System) and MM5 (Mesoscale Model) meteorological data sets are used in the HYSPLIT and Trajectory Analysis models, respectively. Each trajectory had a run time of 32 hrs. and starting heights of 10m, 500m and 1000m. The wind back trajectories are 32-hr back trajectories starting at the La Porte site. The trajectories start at 5 p.m., each dot representing one hour. The three different colors of the back trajectories represent aboveground heights of the wind: green, brown, and blue represent 10, 500,and 1000 meters above the ground, respectively. 5.1 Overview Emissions from wildfires were calculated by projecting the daily fire information (location and acreage) onto a GIS map with spatial composite emission factors. Composite emission factors at the location of a fire were multiplied by the acreage of the fire to obtain daily pounds of emissions of each pollutant (recall that, within the same cover code, each pollutant has a different composite emission factor.) Since fires are treated as points, only one land cover code is assigned to each fire, which will not be entirely accurate if a fire is large enough to encompass two or more different land cover codes. However, since few cover types and emission factors are used to characterize the vegetation of the modeling domain, relatively large geographical areas (sometimes covering up to 10 million acres, or one tenth of the Texas territory) are characterized by a single emission factor. As the largest fires range from 60,000 to 70,000 acres, using a single land cover type for each fire should be a minor source of uncertainty. 16 5.2 Total Acreage Burned in Texas in 2000 The wildfire activity in Texas during the year 2000 was two times larger than the activity in all of 1996 and almost four times larger than in all of 1997. 219,000 acres were burned in wildfires in the year 2000, as opposed to 109,000 and 56,000 in 1996 and 1997, respectively. 5.3 Total Acreage Burned in Texas during August to September, 2000 From August to September 2000, 121,000 acres were burned in wildfires in Texas and most of the fires occurred in East Texas. Estimates for the years 1996-97 based on Dennis (2000) attribute 28,000, 13,000, and 30,000 acres to agricultural, slash, and prescribed range burning activities in August and September, respectively. These last three estimates were possibly smaller in the year 2000 due to drought conditions. Figure 2 shows that wildfire burns exceeded other types of burns. 140000 120000 Acres 100000 80000 60000 40000 20000 0 Wildfires Agricultural Slash Prescribed range Type of fire Figure 2: Acreage burned in different types of fires in Texas in August – September 2000. 5.4 Total Wildfire Acreage Burned in HGBPA Subdomain The acres burned by wildfires in the HGBPA Subdomain during August – September 2000 are shown in the figure below. The period of most intense fires ranged from August 31 to September 8. The days of highest fire activity were September 4 and 6. 17 14000 Acres Burned (Acres) 12000 10000 8000 6000 4000 2000 0 9/26/2000 9/19/2000 9/12/2000 9/5/2000 8/29/2000 8/22/2000 8/15/2000 8/8/2000 8/1/2000 Fire Date Figure 3: Acres burned in wildfires in the HGBPA subdomain. During August – September, 2000. 5.5 Wildfire Emissions in HGBPA Subdomain The estimated emissions of CO, NMHC, PM2.5, and NOX in the HGBPA Subdomain are shown in the graphs of Figure 4. These graphs also include the daily average emissions of CO, NMHC, and NOX from light duty gasoline vehicles (LDGV) in the HoustonGalveston area, a category that excludes diesel fuel vehicles (Harley, personal communication). Figure 4 shows that (1) emissions of pollutants from fires exceeded at times emissions from LDGV, and (2) the period of highest emissions from fires falls between August 31 and September 8 for all emissions. The highest emissions during this short period were approximately 3700 short tons/day, 250 short tons/day, 340 short tons/day, and 50 short tons/day for CO, NMHC, PM2.5, and NOX, respectively. 18 9/14/2000 9/18/2000 9/22/2000 9/26/2000 9/30/2000 9/10/2000 9/14/2000 9/18/2000 9/22/2000 9/26/2000 9/30/2000 9/10/2000 9/14/2000 9/18/2000 9/22/2000 9/26/2000 9/30/2000 Fire Date 19 9/10/2000 8/1/2000 8/5/2000 8/9/2000 8/13/2000 8/17/2000 8/21/2000 8/25/2000 8/29/2000 9/2/2000 9/6/2000 8/1/2000 8/5/2000 8/9/2000 8/13/2000 8/17/2000 8/21/2000 8/25/2000 8/29/2000 9/2/2000 9/6/2000 9/6/2000 9/2/2000 8/29/2000 8/25/2000 8/21/2000 8/17/2000 8/13/2000 150 short tons/day (LDGV) 200 8/9/2000 250 150 100 50 NMHC (Short Tons) 1200 short tons/day (LDGV) CO Emissions (short tons) 4000 3500 3000 2500 2000 1500 1000 500 0 8/5/2000 8/1/2000 400 350 300 250 200 150 100 50 0 PM 2.5 (Short Tons) CO Time Series Fire Date NMHC Time Series 300 0 Fire Date PM 2.5 Time Series NOx (Short Tons) NOx Time Series 150 135 120 105 90 75 60 45 30 15 0 146 short tons/day (LDGV) 9/30/2000 9/26/2000 9/22/2000 9/18/2000 9/14/2000 9/10/2000 9/6/2000 9/2/2000 8/29/2000 8/25/2000 8/21/2000 8/17/2000 8/13/2000 8/9/2000 8/5/2000 8/1/2000 Fire Date Figure 4: Emissions of CO, NMHC, PM2.5, and NOX from fires in the HGBPA Subdomain during August – September, 2000. Emissions (short tons) In Figure 5, wildfire NMHC and NOX emission magnitudes on August 31, 2000 and September 4, 2000 in the HGBPA Subdomain (last four columns in Figure 5) are compared with VOC and NOX emissions from LDGV on September 8,1993 and with the daily average of VOC and NOX emissions in 1996 in the 8-county Houston-Galveston (HG) area (first four columns). The figure indicates that NMHC emissions from wildfires are considerable compared to VOC emissions from LDGV. 450 400 350 300 250 200 150 100 50 0 VOC/NMHC (t/d) NOx (t/d) 9/8/1993 (8- 1996 Daily Avg. County HG Area) (8-County HG Area) 8/31/2000 9/4/2000 Figure 5: Comparison of LDGV emissions of VOC and NOX in the 8-county HG area (first four columns) with wildfire emissions of NMHC and NOX in the HGBPA domain (last four columns). 20 5.6 Observational Evidence: TEOM Results The temporal distribution of wildfire emissions, predicted with the inventory developed in this work, can be compared to ambient measurements of fine particulate ,matter, which can be an effective tracer for fire activity. Six monitors based on Tapered Element Oscillating Microscale (TEOM) technology recorded PM2.5 concentrations within the HGBPA area. The TEOM Domain and the location of the monitors are shown in Figure 6. The observational TEOM data and the findings of this study are qualitatively in agreement. An hourly time series of PM2.5 concentration at the monitor sites during August 22 – September 7, 2000 is shown in Figure 7. The figure shows PM2.5 concentration peaks on September 4 and September 6, and these two days are characterized by the largest fire activity in the HGBPA Subdomain. In Figure 8, the PM2.5 concentrations obtained by interpolating the TEOM observational data for September 4 (Figure 8a) is contrasted with the fire and 32-hour wind back-trajectory data found in this study (Figure 8b). The starting point and time of the wind trajectories is La Porte, 5:00 p.m. The different colors represent the wind’s height above ground at the starting point (La Porte). 3390089 2010026 2450022 2011034 2011039 1670014 Figure 6: Details of TEOM Domain (black line), TEOM monitors (colored points), and HGBPA Subdomain (red line). 21 PM2.5 Concentration ( µg/m3) 200 1670014 2010026 2011034 2011039 2450022 3390089 175 150 125 100 75 50 25 Date and Time Figure 7: Time series of TEOM monitors PM2.5 measurements for August 22 - September 7, 2000. Figure 8b shows that on that particular day, wind from the Northeast of Houston could have carried particulate matter from the large fires in East Texas to the location of the monitors in the Houston area. Figure 8a shows a steep concentration gradient possibly caused by fire emissions. The interpolation performed for Figure 8a was done for each hour during August 22 – September 7, 2000; the results have a high uncertainty because only six data points (corresponding to the six TEOM monitors) were available for the interpolation. 22 9/07 00:00 9/06 00:00 9/05 00:00 9/04 00:00 9/03 00:00 9/02 00:00 9/01 00:00 8/31 00:00 8/30 00:00 8/29 00:00 8/28 00:00 8/27 00:00 8/26 00:00 8/25 00:00 8/24 00:00 8/23 00:00 8/22 00:00 0 (a) (b) Figure 8: (a) Interpolated TEOM monitor data of PM2.5 concentrations for September 4, 2000 at 5:00 p.m. within the TEOM Domain. (b) Fires (red points) and 32-hour wind-back trajectories starting at 5:00 p.m. for September 4, 2000. The different back-trajectory colors represent the wind’s height above the ground at the starting point (La Porte): green: 10 meters above ground, brown: 500 m, blue: 1000 m. However, thorough wind mixing occurred on that day, so that, except at the starting point, the different wind trajectories cannot be allocated onto a vertical layer. 23 6. Preparation of a CAMx-Ready Input File The final goal of this study is to prepare a fire emissions input file suitable for use in the Comprehensive Air Quality Model with extensions (CAMx). The Emissions Preprocessor System, version 2.0 (EPS2.0) was used to create a CAMx-ready input file. In addition, fire plume rise was calculated. The CAMx-ready input file covers the period of August 25 to September 1, 2000, which is the 2000 CAMx Modeling Episode. 6.1 Overview The fire emissions inventory was preprocessed using the Urban Airshed Model (UAM) EPS2.0. The wildfires were modeled as point sources with no plume-in-grid, which allocates the emissions of a point onto an entire grid cell. EPS2.0 input includes: • A data file in Aerometric Information Retrieval System (AIRS) Facility Subsystem (AFS) format • A chemical split factor file (CHEMSPLIT), and • A temporal split file (TMPRL). 6.2 AFS File The AFS file contains information on the location of the fires and the emissions registered during each fire event. The AFS file was prepared using the results of this study. 6.3 Chemical Speciation of NMHCs EPS2.0 recognizes only six types of emissions: CO, VOC, PM, PM10, and NOX. The VOC category is equivalent to the NMHC category in this study, and it is broken down into Carbon Bond-IV (CB-IV) species. CB-IV species are groups of organic compounds or fragments of compounds that have similar reactivities, and NMHCs input into EPS2.0 must be broken down into CB-IV groups. CHEMSPLIT is the file that contains this information. The speciation of NMHCs was based on data collected on the combustion of loblolly pine vegetation, shown in Table 8 (Hays et al., 2002). The table indicates that ethylene, ethane and propylene are the predominant species, comprising as much as 46% of the total NMHC emissions. 24 Table 8: Mass Percents (%) of Total gaseous NMHC of different chemical species in Loblolly pine. Chemical Species n-alkanes ethane propane butane pentane hexane heptane octane nonane decane undecane dodecane alkenes ethene propene isobutene/1-butene trans-2-butene cis-2-butene 1-pentene trans-2-pentene cis-2-pentene 1-hexene 1-heptene 1-octene 1-nonene 1-undecene 1-dodecene isoprene 1,3-butadiene alkynes ethyne branched alkanes isobutane 2,2-dimethylbutane 2-methylpentane Mass Percent (%) of Total gaseous NMHC in Loblolly pine 12.71 4.43 1.60 0.70 0.38 0.28 0.25 0.31 0.31 2.08 21.24 12.22 2.79 1.08 0.82 0.85 0.53 0.28 1.68 0.97 0.78 0.44 0.42 0.20 3.44 2.27 2.82 0.39 0.50 0.71 25 2,4-dimethylpentane 2,2,4-trimethylpentane 2,3,4-trimethylpentane 2-methylhexane 3-methylhexane 2-methylheptane 3-methylheptane branched alkenes 3-methyl-1-butene 2-methyl-1-butene 2-methyl-2-butene 4-methyl-1-pentene cyclic compounds cyclopentane cyclopentene methylcyclohexane α-pinene β-pinene aromatic compounds benzene toluene ethylbenzene m-, p-xylene styrene o-xylene isopropylbenzene n-propylbenzene m-ethyltoluene p-ethyltoluene 1,3,5-trimethylbenzene o-ethyltoluene 1,2,4-trimethylbenzene 1,2,3-trimethylbenzene m-diethylbenzene p-diethylbenzene 0.01 0.13 0.15 0.17 0.43 0.05 0.13 0.51 0.74 1.37 0.10 0.06 0.63 0.15 0.24 0.04 5.15 5.52 0.71 2.52 0.66 0.75 0.10 0.14 0.48 0.22 0.12 0.12 0.80 0.30 0.02 0.01 Source: (Hays et al., 2002) 26 The NMHCs listed in Table 8 are further classified into CB-IV species. A spreadsheet program is available at http://pah.cert.ucr.edu/~carter/emitdb/ to classify NMHCs into CB-IV species. The input to this program includes Chemical Abstracts Service (CAS) number and mass fraction of the chemical species. The results of the chemical split of NMHC into CB-IV species are shown in Table 9. Table 9: CB-IV Speciation Profile for NMHCs CB-IV Species Moles of CB-IV species/gram of Total NMHC PAR [Paraffin carbon bond (C-C)] OLE [Olefinic carbon bond] TOL [Toluene] XYL [Xylene] 7.501*10-4 4.807*10-4 FORM [Formaldehyde] 1.061*10-4 ALD2 [High molecular weight aldehydes] 1.314*10-3 ETH [Ethene] 7.57*10-3 ISOP [Isoprene] MEOH [Methanol] ETOH [Ethanol] UNR [Unreactive Species] 5.046*10-4 0.0000 0.0000 1.879*10-2 4.931*10-3 1.339*10-2 6.4 Calculating fire plume rise To accurately model the emission inventory, a method to determine the correct vertical placement of the emissions must be defined. The placement of the emissions is a function of the plume rise. CAMx has its own algorithm to calculate plume rise. TUPOS (Turbulence Profile Sigmas) model for elevated buoyant releases is implemented as a sub-routine in Fortran Language in CAMx called plumerise.f (ENVIRON, 2000). Equations recommended by Briggs (1984) and Turner et.al. (1986) are used in this model to calculate the plume rise layer-by-layer so that the effects of changing vertical structure of wind and temperature could be included (Turner et.al., 1986). TUPOS model is recommended for calculating the plume rise for stack emissions, which have high exit velocities. Unfortunately, this model has no provision to calculate the plume rise for area source emissions such as fire emissions, since it does not take buoyant rise into account. 27 6.4.1 Existing Plume Rise Models The FIREPLUME and CALPUFF models were used to perform plume rise calculations. The results were then input into CAMx using “dummy” parameters. 6.4.1.1 FIREPLUME model The FIREPLUME model was developed (Brown et al., 1999) to simulate atmospheric dispersion and air quality impacts of fire plumes and other smoke sources. The FIREPLUME model predicts the ground-level concentration resulting from chemicals emitted from or within 1) instantaneously discharged thermals or explosive discharges, 2) fires that generate hot continuous plumes 3) smoldering or decaying fires. The FIREPLUME model is an extension of a Lagrangian particle model (MCLDM). The ability to treat buoyant plumes was added to MCLDM by Brown et al. (1996). In this model, plume rise of fires can be calculated according to the Brigg’s two-thirds law, which is applicable in cases where the buoyancy source has low initial momentum. Fires clearly fall into this category. 3r x 2 r 3 o + o ∆h = 4 β 2 F 2 K 3 β 1/ 3 − ro (1) β where ∆h is the plume rise, x is the downward distance, ro is the fire radius [m], K is the velocity ratio (U/wo), β is the entrainment coefficient and F is the Froude number. 1/ 2 wo 2 ρ a F = (2) 2∆ρr g o where wo is the initial vertical velocity [m/s], ρ is the air density [kg/m3]and ∆ρ is the initial density difference between ambient air and the fire plume. Final rise Due to the effects of entrainment into the plume and thermal stratification of the atmosphere, the rise of the fire plume is limited. It can be calculated depending on stability class (stable, neutral, unstable). For stable conditions, plume rise is limited by thermal stratification. Based on a survey of field data Briggs (1984) suggests that the final rise in stably stratified air is 1/ 3 rU2 ∆h f = 2.1 2o 2 3 N F K (3) where ∆hf is the final rise in [m] and N is the Brunt Vaisala frequency. 1/ 2 g ∂θ N can be calculated as N = , (Arya, 1999) θ ∂z 28 For neutral conditions, ambient turbulence limits the rise by breaking up the plume. The final rise in this case is the level at which the internal turbulent dissipation rate of the plume matches the ambient turbulent dissipation rate. rU2 (4) ∆h f = 0.76 2o 2 3 u* F K where u* is the friction velocity [m/s]. In this study, this value is approximated to be 10% of wind velocity at 10 meters. In unstable conditions, plume rise is also limited by turbulence. However, the turbulent dissipation of the downdrafts is equated with the plume dissipation rate since downdrafts are responsible for bringing elevated material to ground level. r U2z 2/3 ∆h f = 4.5 o 2 2i 3 4w * F K 3/5 (5) where zi is the inversion height [m] and w* is the convective velocity scale [m/s]. g (6) w* = [ ( w'θ ' ) s z i ]1 / 3 θv where ( w'θ ' ) s is the surface heat flux [K.m/s] and θv is the mean virtual potential temperature which can be approximated as actual temperature at that height. In the literature (Brown et al., 1999), the power of inversion height in equation (5) is one, making the unit of final rise unmatched with [m]. According to Weil J.C (1988), power of inversion height is 2/3 and the unit of final rise is matched with [m]. In practice, the neutral plume rise relationship serves as a limiting case since both the stable and unstable limiting rise relationships go to infinity as neutral conditions are approached. The literature suggests using the lesser of the stable or unstable final rise estimate (which ever is applicable) and the neutral estimate. Therefore, in unstable conditions the final rise is given by: ∆h f = min{∆h f [Eq.(3)], ∆h f [Eq.(4)] whereas for stable conditions ∆h f = min{∆h f [Eq.(5)], ∆h f [Eq.(4)] The basic theory of plume rise (based on the so-called Brigg's formulas) is limited to assumptions of uniform wind field and constant stability in the atmospheric layers through which the plume rises. It does not account layer-by-layer calculation with residual flux as TUPOS does in CAMx. It calculates only final plume rise. This may create an issue of changing in vertical structure of wind and temperature. 29 Meteorological data, including U, ρ, and ∆ρ, are inputs to the equations. Meteorological data stratified in vertical layers are available in CAMx simulations on limited numbers of days during the Texas Air Quality Study and from the National Oceanic and Atmospheric Administration (NOAA). 6.4.1.2 CALPUFF Model CALPUFF is a non-steady state air quality modeling system for a variety of air quality modeling studies, including buoyant area emission sources such as forest fires. This system consists of three main components: CALMET (a diagnostic 3-D meteorological model), CALPUFF (the transport and dispersion model), and CALPOST (a postprocessing package). The area source plume model in CALPUFF calculates the plume rise and is applicable to large forest fires. Unlike the FIREPLUME Model, the plume rise model in CALPUFF is formulated on the basis of mass, momentum and energy balances. The resulting time dependency to the plume rise can be calculated assuming that the plume motion is quasi-steady state so the time-derivatives in the governing equations are neglected. This assumption is reasonable because the time scale for plume rise is much shorter than that of the fire life span. The derivation of the governing equations are given below: The mass conservation equation d (ρU sc r 2 ) = 2rαρ a | U sc − U a cos ϕ | +2rβρ a | U a cos ϕ | ds where α=0.11 and β=0.6 are the entrainment parameters corresponding to the differences of velocity components between the wind and the plume in directions parallel and normal to the plume centerline respectively Ua = the ambient horizontal wind speed Usc = u 2 + w 2 ρ , ρa = the plume density and air density, respectively s = length of the plume centerline measured from the emission source ϕ = centerline inclination The momentum equation in the wind direction dU a d ρU sc r 2 (u − U a ) = −r 2 ρw ds dz ( ) (7) The momentum equation in the vertical direction is a balance among inertial acceleration, entrained momentum and buoyancy: 30 d (ρU sc r 2 w ) = gr 2 (ρ a − ρ) ds (8) g = gravitational acceleration The energy equation dT d g 4 ρwr 2 − R p r (T 4 − Ta ) ρU sc r 2 (T − Ta ) = − a + ds dz C p ( ) (9) 2εσ Rp = /Cp = 9.1 x 10-11 kg/ m2K3s σ = Stefan-Boltzmann constant = 5.67 x 10-8 w/m2K4 ε = emissivity = 0.8 To close the equation set, two geometric relations are needed: dz w = = sin ϕ ds U sc dx u = = cos ϕ ds U sc In order to utilize this model, a sub-routine in CALPUFF called “numrise” is extracted. Inputs needed for this sub-routine are: Effective Temperature of release (K) Effective radius of release (m) Effective exit velocity (m/s) Number of points in trajectory passed EPM (Emission Production Model) and EPM2BAEM The Emission Production Model, EPM, is the emission source strength model for fires in widespread use. EPM has been used satisfactorily as input to models of long and shortrange plume dispersion. Applicability of an Emission Production Model is to predict air pollutant source strength, heat release rate, and plume buoyancy from all fire environments and all fuel types. CALPUFF has a conversion utility called “EPM2BAEM”, which is the interface between EPM output and CALPUFF input. By using this utility, with our emission inventory and heat release rate, Effective Temperature of release (Plume temperature) and Effective exit velocity (vertical velocity) can be estimated. 31 6.4.1.3 Obtaining Input Data The input parameters for FIREPLUME and CALPUFF models are given in Table 10. Meteorological data were extracted from CAMx input files and also from MM5 output. The hourly modeling data files and related documents for the TexAQS 2000 period were downloaded from Texas Commission on Environmental Quality (TCEQ) website (www.trnrcc.state.tx.us). Table 10: Input Data for FIREPLUME and CALPUFF Models Input FIREPLUME Model CALPUFF Model CAMx Input Files Layer 1-2 in CAMx stucture CAMx Input Files Layer 1-14 in CAMx stucture CAMx Input Files Layer 3 in CAMx stucture CAMx Input Files Layer 1-14 in CAMx stucture Meteorological data Temperature Horizontal Wind Pressure CAMx Input Files Layer 1-14 in CAMx stucture Mixing Height MM5 Output Heat Flux at Surface Plume Characteristics Temperature of release Exit vertical velocity Heat Release Acres Burned MM5 Output 900 – 1600 K 900 – 1600 K CALPUFF Methodology CALPUFF Methodology Emissions Inventory Emissions Inventory Emissions Inventory Emissions Inventory 32 Fortran codes were written to extract the metrological data from CAMx input files. The following are the fortran codes to extract wind, temperature and pressure data. Wind File Hour, idate Loop from 1 to nlay layers: ((uwind(i,j,k), i=1,nx), j=1, ny) ((vwind(i,j,k), i=1,nx), j=1, ny) ((dummy, i=1,nx), j=1, ny) Temperature File Hour, idate, ((temps(i,j), i=1,nx), j=1, ny) Loop from 1 to nlay layers: Hour, idate, ((temps(i,j), i=1,nx), j=1, ny) Pressure File Loop from 1 to nlay layers: Hour, idate, ((height(i,j), i=1,nx), j=1, ny) Hour, idate, ((press(i,j), i=1,nx), j=1, ny) Mixing height and surface heat flux MM5 output reports meteorological data, including mixing height and surface heat flux, which are used in FIREPLUME model. To extract this information into a Microsoft Access database, the existing fortran code was modified and used for this task. The original Fortran code for extracting MM5 can be found at http://mailman.ucar.edu/pipermail/mm5-users/2002/000073.html. A visual basic code was created to revise Greenwich time information used in the MM5 model to standard time (Greenwich Time – 6 hours). Initial vertical velocity Both CALPUFF and FIREPLUME models require initial velocity of fire plume to calculate the plume rise. The calculation procedure (Chang et al., 1999) for initial vertical velocity used in CALPUFF is as follows: 33 Once the area of a fire is specified, the initial plume radius rp can be readily approximated by A rp = (10) π The plume buoyancy flux Fb [m4/s3] is calculated based on the following equation: Fb = g Tp − Ta Tp w p rp 2 (11) where Tp, Ta are the initial plume temperature and the ambient temperature [K], respectively. wp is the initial plume vertical speed [m/s]. From Briggs (1975), Fb is related to the heat emission, Qh [J/s] as Fb = gQ h πc p ρ a Ta (12) Cp = 1004 J/kgK, ρa is the ambient air density [km/m3] From ideal gas law, the above equation can be written as P (13) Fb = 8.8x10 −6 s Q h Pa where Ps is the standard sea level pressure (=101325 Pa), and Pa is the ambient pressure (Pa). Assuming Pa~Ps, then equating equation (11) and (13) gives wp = 8.8x10 −6 Q h x Tp g(Tp − Ta )rp (14) 2 Fire plume temperature The plume temperature and other source characteristics are source-specific. Unfortunately, the fire plume temperature information is not available in the literature and not reported by the fire agencies. Therefore a typical plume temperature range of 900-1600 K is assumed. Heat release and Acres burnt The daily acreage burned is uniformly distributed for 24 hours. To run the FIREPLUME model, all input parameters are stored in a Microsoft Access database for easy access. A 34 Visual Basic programming program is used to extract data from Access database and perform the calculations. For CALPUFF, plume characteristics were specified in an Excel file. A Fortran code “main.f” was created to link this fire plume characteristics and meteorological data to the extracted CALPUFF subroutines and further details are given in Section 6.4.2. Sample of Fire Events The focus of this study is limited to HG-BPA (Houston-Galveston, Beaumont-Port Arthur) sub-domain since most of the fire events during TexAQS 2000 occurred in this domain. The metrological data are available for the TexAQS modeling episode days (August 25 – September 1, 2000). To observe the performance of plume rise model, only large fire events that burnt more than 500 acres were used. This limited the analysis to three fires, with fire ids 1085, 1094 and 1033. The x-y coordinates of each fire, (X1,Y1 and X2,Y2, which are the coordinates on CAMx and MM5 domains, respectively) are shown in Table 11. Table 11: Access database of selected Forest Fires Fire ID 1033 1085 1094 Fire Date/Start Date 30-Aug-00 31-Aug-00 01-Sep-00 LatDD 30.2590 30.5210 30.9019 LongDD -95.0060 -93.0480 -93.5894 Total Acres Heat_Release X1 Y1 X2 Burned (Btu)/day 8.42E+10 31 45 66 1000 2.15E+11 77 56 112 4000 6.68E+10 64 65 99 793.2 Y2 77 88 97 6.4.2 Using Models FIREPLUME: In the FIREPLUME model, uniform wind field and constant stability in the atmospheric layers through which the plume rises are assumed. Only wind data of layer 1 and layer 3 were used. Lapse rate, which represents the atmospheric stability conditions, was calculated based on temperature data for the first two layers. CALPUFF: To use CALPUFF model for plume rise calculations, several sub-routines were extracted. The subroutines are “numrise.f”, “numpr1.f”, “param.puf”, “numparam.puf”, “rate.f”, “marching.f”, “zmet.f”, “unlump.f”, “ambient.puf”, and “ar2.puf”. To link meteorological data, fire data, and all other sub-routines each other, main code “main.f” was created using Fortran. Main.f defined the fourteen vertical layers used in CAMx model, so that ambient temperatures, ambient pressures, and ambient wind speeds in each different layer were used to calculate the fire plume trajectory step by step. 35 Inputs needed for “main.f” are: 1. Meteorological data 2. Fire data 3. Non-variable conditions such as defining layers Fire data in “main.f” is the input for CALPUFF sub-routine “numrise.f”, and it is described as follows: 1. Release height (m) 2. Effective temperature of release (K) 3. Effective radius of release (m) 4. Effective exit velocity (m/s) 5. Number of points in trajectory passed back to calling program (final point is “final rise”) 6.4.2.1 FIREPLUME Results Sensitivity runs and model observations indicate that plume temperature has negligible effect the plume rise calculations. Only heat release (J/s) parameter has significant effect on the plume rise. Though the radius of fire does not explicitly contribute to plume rise, it is implicitly included in heat release value. As the first step of calculation, wind data of layer 1 was used to observe the characteristics of plume rise as shown in Figure 9. Horizontal lines represent top height of layer 3, 4 and 5 of the CAMx grid structure. Note that most of the plumes rise values are above layer 3. Thus, choosing layer 3 for wind velocity data may be a good approximation. All further calculations in this work are based on wind data of layer 3. Well mixed conditions are assumed in all the grids CAMx model. Therefore plume heights falling within a particular layer were treated to be of same height as the top of that layer. Figure 10 shows the plume rise with vertical CAMx structure. All the three fire events show similar trend of plume rise with low height at night and peak during the late afternoon. From nighttime till 10 am in the morning, stable atmospheric conditions occur indicating low turbulence in the atmosphere. On the other hand, unstable conditions occur during the day with the maximum mixing height during late afternoon. This condition leads to a vertical convective transport, resulting in high plume rise in the afternoon. The maximum plume rise is in the range of 800-1300 m. 36 Plume rise calculations using different layers for velocity data--AUG 30, 2000 Fire ID 1033 3500 plume rise (m.) 3000 2500 2000 z= 1 1500 z= 3 1000 500 0 0 2 4 6 8 10 12 14 16 18 20 22 24 time Plume rise calculations using different layers for velocity data--AUG 31, 2000 Fire ID 1085 plume rise (m.) 1800 1600 1400 1200 1000 800 z= 1 z= 3 600 400 200 0 0 2 4 6 8 10 12 14 16 18 20 22 24 time plume rise (m.) Plume rise calculations using different layers for velocity data--Sep 1, 2000 Fire ID 1094 1800 1600 1400 1200 1000 800 600 400 200 0 z =1 z =3 0 2 4 6 8 10 12 14 16 18 20 22 24 time Figure 9: Plume rise calculations with velocity data of different CAMx layers 37 Fireplume calculations Aug 30, Fire ID 1033 , 1000 acres 1600 plume rise (m.) 1400 11 1200 10 1000 9 800 8 600 7 6 400 5 4 200 3 0 0 2 4 6 8 10 12 time 14 16 18 20 22 Fireplume calculations Aug 31, Fire ID 1085 , 4000 acres 1600 plume rise (m.) 1400 11 1200 10 1000 9 800 8 600 7 6 400 5 4 200 3 0 0 2 4 6 8 10 12 time 14 16 18 20 22 18 20 22 Fireplume calculations Sep 1, Fire ID 1094 , 800 acres 1600 plume rise (m.) 1400 11 1200 1000 800 600 400 6 5 4 200 3 2 0 0 2 4 6 8 10 12 time 14 16 Figure 10: Plume rise with vertical CAMx structure (with wind velocity-layer 3) 38 As shown in Figure 10, Fire ID 1033 does not have a peak at any specific time of the day but it tends to have high plume rise during many hours in the afternoon. The gradual change in the plume rise during the afternoon of this fire event is due to the low wind velocity as shown in Figure 11. Further the low wind velocity favors vertical displacement rather than horizontal dispersion, resulting in high plume rise. Peaks in the plume rise behavior occurred on Aug 31 at 5 pm and on Sep 1 at 6 pm. Lapse rates at these two times are 0.008915 and 0.009605 degree/m., respectively. These are the only values that are close to adiabatic lapse rate, which is 0.0098 degree/m., representing stable near neutral atmospheric condition. Sensitivity runs were performed to investigate the plume rise behavior for neutral conditions. For neutral conditions, the plume rise values are very high compared to stable and unstable modes. plume rise plume rise (m) Plume rise for Fire ID 1033 Aug 30 ,2000 wind 1000 10.00 800 8.00 600 6.00 400 4.00 200 2.00 0 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 time Figure 11: Plume rise of fire ID 1033 and wind velocity on Aug 30, 2000 39 6.4.2.2 CALPUFF Calculations One of the input variables for the CALPUFF calculations, with the largest uncertainty, is fire temperature. Accurate temperatures for the fires of interest are not available, so a typical temperature range of 900 - 1200K was assumed. Analyses were done at three different temperatures- 900K, 1200K, and 1600K. Figure 12 represents fire plume rise in meters for each fire event. As shown in the Figure, temperature has negligible effect on the plume rise. Similar trends in plume rise are observed for the three fire events. For fire ID 1033 on August 30 and fire ID 1094 on September 1, plume rise value is around 400 m during the nighttime period (between midnight and 10 am) and 9 pm through midnight. During the daytime, plume rise increases rapidly with mixing height and reaches a maximum plume height in the range of 1000 – 2000 m from noon to 5pm. As mentioned above, each grid and layer in CAMx domain is assumed to be well mixed. Therefore, a plume that reaches any point in a layer will be considered to at the top of that layer. Figure 13 shows the maximum plume rise results. 40 Fire ID 1033 3000 12 2000 11 1500 Temp 900K, 42 acre/hr Temp1200K, 42 acre/hr 1000 Temp 1600K, 42 acre/hr 2200 2000 1800 800 600 400 200 0 8 7 10 9 1600 4 0 5 1400 6 1200 500 1000 Plume rise(m) 2500 Hour Fire ID 1085 Plume rise(m) 2500 12 2000 Temp 900K, 167 acre/hr 1500 1000 500 7 6 11 10 9 8 Temp1200K, 167 acre/hr Temp 1600K, 167 acre/hr 80 0 10 00 12 00 14 00 16 00 18 00 20 00 22 00 60 0 40 0 0 20 0 0 Hour Fire ID 1094 1200 10 800 9 600 400 Temp 900K, 33acre/hr 8 Temp1200K, 33 acre/hr Temp 1600K, 33 acre/hr 2200 2000 1800 1600 1400 1200 1000 800 3 600 200 0 0 12 7 6 5 4 200 400 Plume rise(m) 1000 Hour Figure 12: Plume rise calculations with different fire temperatures. Fire ID 1033, 1085, and 1094 are the fire events occurred in Aug 30, Aug 31, and Sep 1, respectively. 41 3500 3000 2500 2000 1500 1000 500 0 Temp 900K, 42 acre/hr 13 12 2200 2000 1800 1400 1200 1000 1600 10 9 8 800 600 400 200 7 6 5 0 Plume rise(m) Fire ID 1033 Hour 3500 3000 2500 2000 1500 1000 500 0 Temp 900K, 166 acre/hr 13 12 0 22 0 0 20 0 0 18 0 0 16 0 0 14 0 0 12 0 0 11 10 9 10 0 80 0 60 0 40 0 20 0 8 7 6 0 Plume rise(m) Fire ID 1085 Hour Fire ID 1094 1200 10 9 800 8 600 400 Hour Figure 13: CALPUFF Plume rise calculations with CAMx vertical layers 42 2200 2000 1800 1600 1400 1200 1000 800 3 600 0 12 400 200 7 6 5 4 200 Plume rise(m) 1000 0 Temp 900K, 33acre/hr 6.4.2.3 Comparison between FIREPLUME and CALPUFF results For the purposes of regional modeling, a simple profile of plume rise, combining the results of CALPUFF and FIREPLUME will be assumed. Combining the results of FIREPLUME and CALPUFF models give two proposed profiles as shown in Figure 14. Figure 14. (a) represents a low wind day in the afternoon and Figure 14. (b) indicates near neutral condition during the late afternoon. Both models, FIREPLUME and CALPUFF, agree well at night time (stable condition) between 10 pm at night through 10 am in the morning. Average plume rise is within level 5 of the CAMx vertical structure. They both also give the same trend of peak value during mid-late afternoon. Peaks plume heights range from layers 11 to layer 14. Top of level 12 is chosen to represent this high peak in the afternoon time. Proposed plume rise profile of low wind day plan A. plume rise (m.) 2500 12 2000 1500 11 10 1000 9 7 500 5 3 0 0 2 4 6 8 10 12 time 14 16 18 20 22 Proposed plume rise profile with high peaks in the afternoon- plan B. plume rise (m.) 2500 12 2000 1500 1000 500 5 0 0 2 4 6 8 10 12 time 14 16 18 20 Figure 14 (a) Plume rise for low wind day showing a gradual change during the day; on a near neutral atmospheric stability in the afternoon. 43 22 (b) Plume rise 6.4.2.4 Conclusions and Recommendations CALPUFF and FIREPLUME model were selected as the appropriate models for estimating plume rise for wild fires, and their plume rise results were compared. Although the two models show some differences in the magnitude and temporal variation of the plume rise, the model results are in reasonable agreement for the purposes of regional modeling. To integrate these results into CAMx, simple plume rise profiles were chosen. The proposed profiles suggest low plume rise at night time and high plume rises during late afternoon. 44 7. References Arya, S. P (1999). Air Pollution Meteorology and Dispersion. Oxford University Press, NewYork. Briggs, G. A. (1975). Plume rise predictions. In: Lectures on Air Pollution and Environmental Impact Analysis, D. A. Haugen (ed.), American Meteorological Society, Boston. 59-111. Briggs, G.A. (1984). Plume Rise and Buoyancy Effects, in Atmospheric Science and Power Production, D. Randerson (ed.), DOE/TIC – 27601, Weather Service Nuclear Support Office, National Oceanic and Atmospheric Administration, United States Department of Commerce, 327-366. Burgan, R. (1988). 1988 Revision to the 1978 National Fire Danger Rating System, Research Paper SE-273. Asheville, NC: USDA Forest Service, Southeastern Region. Dennis, A. (2000). Inventory of Air Pollutant Emissions Associated with Forest, Grassland and Agricultural Burning in Texas. Masters of Science Thesis, The University of Texas at Austin, Austin, Texas. Dennis, A., M. Fraser, S. Anderson, and D. T. Allen, “Air Pollutant Emissions Associated with Forest, Grassland and Agricultural Burning in Texas,” Atmospheric Environment, 36, 3779-3792 (2002). Brown, D., Dunn, W., Lazaro, M., Policastro, A. (1999): The FIREPLUME model: Tool for Eventual Application to Prescribed Burns and Wildland Fires, Proc. from The Joint Fire Science Conference and Workshop. http://www.nifc.gov/joint_fire_sci/conferenceproc/ Chang, J. C., Scire, J. S. (1999). User’s Guide to the EPM2BAEM Interface Program. Earth Tech, Inc. Concord, Massachusetts. ENVIRON (2000). User’s Guide Comprehensive Air Quality Model with Extensions (CAMx) version 3.10. ENVIRON International Corporation. Novato, California. EPA. (1992). Open Burning. Compilation of Air Pollution Emission Factors, Volume I: Stationary Point and Area Sources, Fifth Edition, Chapter 2.5, AP-42 (GPO 055-00000500-1). US Environmental Protection Agency. Research Triangle Park, North Carolina. Harley, R. Dept. of Civil and Environmental Engineering, University of California at Berkeley. Personal communications with Dr. David Allen, Center for Energy and Environmental Resources, The University of Texas at Austin. 45 Jenkins, B. M. et al. (1996). Atmospheric Pollutant Emission Factors from Open Burning of Agricultural and Forest Biomass By Wind Tunnel Simulations. Volume 2, Results. Cereal Crop Residues. California Air Resources Board (CARB) Project No. A932-126. Reproduced by the National Technical Information Service, PB97-126940. McMahon, C. K. (1983). Characteristics of Forest Fuels, Fires, and Emissions, Presented at the 76th Annual Meeting of the Air Pollution Control Association, Atlanta, GA. Scire, J. S., Strimaitism, D. G., Yamartino R. J. (2000). A User’s Guide for the CALPUFF Dispersion Model v. 5. Earth Tech, Inc. Concord, Massachusetts. Texas Forest Service, 2000: Highlights. Texas Forest Resource Harvest Trends 2000. http://txforestservice.tamu.edu/forest%5Fmanagement/pdf/ht2000.pdf Turner, D.B., Chico, T., Catalano, J.A. (1986). TUPOS-P - A Program for Reducing Hourly and Partial Concentration Files Produced by TUPOS: User's Guide. EPA-600/886/012. U.S. Environmental Protection Agency. Research Triangle Park, North Carolina. Turner, D. B., Chico, T., and Catalano, J. A. (1986). TUPOSCA Multiple Source Gaussian Dispersion Algorithm Using On-Site Turbulence Data. U.S. Environmental Protection Agency. Research Triangle Park, North Carolina (EPA-600/8-86/010). US Census Bureau, 2000. County Population Estimates and Demographic Components of Population Change: Annual Time Series, July 1, 1990 to July 1, 1999. http://eire.census.gov/popest/archives/county/co_99_8.php US Census Bureau, 2001. Population Change for Counties. http://eire.census.gov/popest/data/counties/tables/CO-EST2001-08.php Ward, D.E. and Hardy, C.C. (1991). Smoke Emissions from Wildland Fires. Envrionment International, Vol. 17, pp. 117-134. Ward, D., Peterson, J., Hao, W. (1993). An Inventory of Particulate Matter and Air Toxic Emissions from Prescribed Fires in the USA for 1989. Report A1299, USDA Forest Service, Intermountain Research Station, Missoula, MT. Weil, J.C. (1988). Plume Rise, in Lectures on Air Pollution Modeling, A. Venkatram and J.C.Wyngaard (eds.), American Meteorological Society, Boston. 119-157 Wiedinmyer, C., Strange, I., Estes M. Yarwood, G., and Allen, D., 2000: Biogenic Hydrocarbon Emission Estimates for North Central Texas, Atmos. Environ. 34, 3419 – 3435. Zonato, C., Vidili, A., Pastorino, R., De Faveri, D.M., 1993: Plume Rise of Smoke Coming from Free Burning Fires, J. Hazardous Materials. 34, 69 – 79. 46 Appendix A: Land Cover Code Descriptions Table A- 1: Description of FOFEM land cover codes. Source Category Logging Slash Code 100b 100c 100d 100e 147d Description Corn Residue Hay/Pasture Grasses Sugarcane residue Wheat Residue Pine-Hardwood Slash Debris Prescribed Range, Landclearing Slash 151b Other Forests/Woods Range Agricultural Prescribed Range, Wildland, Land Clearing Slash Wildland Urban Water/Barren 2 Desert Grasslands 3 Plains Grasslands 6 Wet Grasslands 7 Prairie - Tall Grass 18 Shinnery - Moderate Coverage 21 SW Shrub Steppe - Moderate Coverage 22 SW Shrub Steppe - High Coverage 23 Texas Savannah 147c Piney Woods Non-Forest 293 Pinyon - Juniper 100a Cropland Mosaic 147a Pine-Hardwood Natural Forest 147b Pine-Hardwood Plantation 151a Other Forests/Woods Natural 211 Ponderosa Pine Natural 1 Urban 999 Water/Barren 47 Table A- 2: Description of NFDRS LULC codes. NFDRS Code NFDRS Model Vegetation Represented 1 A Western annual grasses 2 B California mixed chaparral 3 C Pine grass savanna 4 D Southern rough 5 E Hardwoods (winter) 6 F Intermediate brush 7 G Short needle conifers with heavy dead load 8 H Short needle conifers with normal dead load 9 I Heavy logging slash 10 J Intermediate logging slash 11 K Light logging slash 12 L Western perennial grasses 13 M Agricultural land 14 N Sawgrass or other thick stemmed grasses 15 O High pocosin 16 P Southern pine plantation 17 Q Alaskan black spruce 18 R Hardwoods (summer) 19 S Alpine tundra 20 T Sagebrush-grass mixture 21 U Western long-needle conifer 22 V Water 23 W Barren 24 X Water 48 Appendix B: Daily Plots of Fires and 32-Hour Wind Back-Trajectories Appendix B-1: Daily Plots of Fires onto the LULC Map Figure B- 1: Legend. The red dots indicate the size of the fire. The colors correspond to vegetation cover codes. Table B-1 contains the description of the cover codes. # # # # # # # 0.1 - 250 acres 250 - 500 acr es 500 - 1000 acres 1000 - 5000 acr es 5000 - 10000 acres 10000 - 15000 acr es 15000 - 20000 acr es Wat er/Barren FOFEM_1 FOFEM_3 FOFEM_6 FOFEM_7 FOFEM_18 FOFEM_21 FOFEM_22 FOFEM_23 FOFEM_100 FOFEM_147 FOFEM_151 FOFEM_293 NFDRS_3 NFDRS_4 NFDRS_6 NFDRS_12 NFDRS_13 NFDRS_14 NFDRS_15 NFDRS_16 NFDRS_18 NFDRS_20 49 Table B- 1: Description of land use categories and associated composite emission factors for PM2.5, NOX, and NMHC. Legend Water/Barren FOFEM 1 FOFEM 2 FOFEM 3 FOFEM 6 FOFEM 7 FOFEM 18 FOFEM 21 FOFEM 22 FOFEM 23 FOFEM 100 FOFEM 147 FOFEM_151 FOFEM_211 FOFEM_293 NFDRS_1 NFDRS_2 NFDRS_3 NFDRS_4 NFDRS_5 NFDRS_6 NFDRS_7 NFDRS_8 NFDRS_9 NFDRS_10 NFDRS_11 NFDRS_12 NFDRS_13 NFDRS_14 NFDRS_15 NFDRS_16 NFDRS_17 NFDRS_18 NFDRS_19 NFDRS_20 NFDRS_21 Composite emission Description Factor PM2.5 (lbs/acre) Water/Barren 0 Urban 0 Desert Grasslands 6.00 Plains Grasslands 13.00 Wet Grasslands 50.00 Prairie - Tall Grass 96.00 Shinnery - Moderate Coverage 46.00 SW Shrub Steppe - Moderate Coverage 41.00 SW Shrub Steppe - High Coverage 65.00 Texas Savannah 111.00 Cropland Mosaic 13.00 Pine-Hardwood Natural Forest 90.00 Other Forests/Woods Natural 123.00 Ponderosa Pine Natural 165.00 Pinyon - Juniper 148.00 Western annual grasses 13.1 California mixed chaparral 341 Pine grass savanna 87.6 Southern rough 132 Hardwoods (winter) 80.5 Intermediate brush 252 Short needle conifers with heavy dead load 436.5 Short needle conifers with normal dead load 146.5 Heavy logging slash 816 Intermediate logging slash 454 Light logging slash 169 Western perennial grasses 19 Agricultural land 0 Sawgrass or other thick stemmed grasses 108 High pocosin 311 Southern pine plantation 66.5 Alaskan black spruce 274 Hardwoods (summer) 45.5 Alpine tundra 79.5 Sagebrush-grass mixture 88.5 Western long-needle conifer 106.5 50 Composite Composite emission emission Factor NOX Factor NMHC (lbs/acre) (lbs/acre) 0 0 0 0 0.70 5.00 1.50 10.00 5.80 38.00 11.10 73.00 5.50 35.00 4.90 32.00 7.60 49.00 12.80 85.00 1.50 10.00 11.60 69.00 16.20 93.00 23.90 125.00 16.50 113.00 1.75 10 57.5 257.5 12 66.8 21.25 100 11.875 61.25 41.25 190.5 68.75 330 23.75 111 145 618 81.25 344 30 128 2.5 14.5 0 0 17.5 82 51.25 235 11.25 50.5 48.25 207.5 7.5 34.5 11.25 60.5 13.75 67 17.5 81 August 1 51 August 2 52 August 3 53 August 4 54 August 5 55 August 6 56 August 7 57 August 8 58 August 9 59 August 10 60 August 11 61 August 12 62 August 13 63 August 14 64 August 15 65 August 16 66 August 17 67 August 18 68 August 19 69 August 20 70 August 21 71 August 22 72 August 23 73 August 24 74 August 25 75 August 26 76 August 27 77 August 28 78 August 29 79 August 30 80 August 31 81 September 1 82 September 2 83 September 3 84 September 4 85 September 5 86 September 6 87 September 7 88 September 8 89 September 9 90 September 10 91 September 11 92 September 12 93 September 13 94 September 14 95 September 15 96 September 16 97 September 17 98 September 18 99 September 19 100 September 20 101 September 21 102 September 22 103 September 23 104 September 24 105 September 25 106 September 26 107 September 27 108 September 28 109 September 29 110 September 30 111 Appendix B-2: Daily Plots of Fires and 32-Hour Wind Back-Trajectories Figure B- 2: Legend. The values in meters (green, brown, and blue dots) correspond to the height above the ground of the wind trajectory at the starting hour (La Porte site). The dots in red correspond to different fire sizes. 112 August 1 113 August 2 114 August 3 115 August 4 116 August 5 117 August 6 118 August 7 119 August 8 120 August 9 121 August 10 122 August 11 123 August 12 124 August 13 125 August 14 126 August 15 127 August 17 128 August 18 129 August 19 130 August 20 131 August 21 132 August 23 133 August 24 134 August 25 135 August 26 136 August 27 137 August 28 138 August 29 139 August 30 140 August 31 141 September 1 142 September 2 143 September 3 144 September 4 145 September 5 146 September 6 147 September 7 148 September 8 149 September 9 150 September 10 151 September 11 152 September 12 153 September 13 154 September 14 155 September 15 156 September 16 157 September 17 158 September 18 159 September 19 160 September 20 161 September 21 162 September 22 163 September 23 164 September 24 165 September 25 166 September 26 167 September 27 168 September 28 169 September 29 170 September 30 171 Appendix C: Contact Summary Table C- 1: Contact Information Institution Texas Interagency Cooridination Center (TICC) Contact Gill Hodges Phone Fax 936-875-4786 936-875-4812 Texas Forest Curt Stripling 936-435-0852 Service (TFS) Louisiana Interagency Corrdination Center Texas Fire Incident Reporting System (TEXFIRS) National Interagency Fire Management Integrated Database (NIFMID) Sheryl Roach 318-473-7152 318-473-7172 E-mail Message Website Address [email protected] Gill Hodges maintains the database of wildfires that occur on Texas State and Private Ownership Lands. Database of wildfires that occurred on the Texas State and Private Ownership Lands for year 2000 was received from her. http://www.usda.gov/nass/ [email protected] , [email protected] [email protected] Written request by E-mail was submitted to TEXFIRS to obtain wildfires records for year 2000 from Texas State Fire Marshal's Office. Records were not yet received. Virginia Garza 512-305-7950 512-305-7910 Daniel Ervin 208-387-5288 He sent the Texas Forest Service Conversion Software to convert the Block and Grid Format to Latitude/Longitude Coordinates She maintains the records of wildfires that occur on Federal Ownership Lands in Louisiana. The records of wildfires that occurred on the Federal Lands in Louisiana for Year 2000 was received from her. [email protected] 172 He maintains the National Interagency Fire Management Integrated Database (NIFMID). NIFMID for year 2000 can be downloaded from http://famweb.nwcg.gov/ and the user's guide for the database can be downloaded from www.fs.fed.us/fire/planning/nist/sit.htm Texas Interagency Cooridination Center (TICC) Glenn Hammond 936-875-4812 Louisiana Department of Louis Heaton 225-925-4500 Agriculture and Forestry United States Dellora Gauger Department of (Northern 406-329-3256 406-329-3359 Agriculture Region) (USDA) Forest Service (FOIA Marianne Coordinators) Frazier (Rocky 303-275-5292 303-275-5299 Mountain) [email protected] Glenn Hammond maintains the database of wildfires that occur on National Forests in the state of Texas. He is the USDA Forest Service's representative at TICC. Database of wildfires that occurred on the National Forests in Texas in year 2000 was received from him. He is the concerned person to contact for wildfire records in the Louisina Dept. of Agriculture and Forestry (LDAF). LDAF has no computer records for wildfires that [email protected] occurred in year 2000 due to their computer system failure. Personal visit to various districts was recommended to obtain the hardcopies of the wildfire records for year 2000. [email protected] [email protected] Joe Sedillo 505-842-3383 505-842-3111 (Southwestern) [email protected] Rochelle Jelaco 801-625-5354 801-625-5240 (Intermountain) [email protected] 173 Freedom of Information Act (FOIA) request letters were submitted by E-mail to all the USDA regional offices requesting wildfire records that occurred on federal ownership in the year 2000. The completed database of the wildfire records that occurred on federal ownership in the United States for year 2000 was received from the Fire & Aviation Management, Forest Service, USDA (14th & Independence, SW, P.O.Box 96090, Washington, D.C. 200906090) Juanita Cuevas (Pacific 707-562-8768 707-562-9041 Southwest) Patty Brandt (Pacific Northwest) 503-808-2268 503-808-2255 [email protected] Andrea Csergei 404-347-7310 404-347-5401 (Southern) [email protected] Paul Witte (Eastern) 414-297-3403 414-297-3808 Cherie Shelley 907-586-8855 907-586-7852 (Alaska) Arkansas Forestry Commission Oklahoma Department of Agriculture, Food & Forestry Alabama Forestry Commission [email protected] Sherry Russell 501-332-2000 Patrick Mc Dowell Lou Hyman 405-522-6146 334-240-9354 [email protected] [email protected] Written request by E-mail was submitted to this person to obtain wildfires records [email protected] for year 2000 in the state of Arkansas. Records were not yet received. [email protected] He is the concerned person to contact for wildfire records in the Oklahoma Dept. of Agriculture and Forestry. Received wildfire records that occurred on the lands under the protection of Oklahoma Dept. of Agriculture and Forestry during AugustSeptember 2000. He is the concerned person to contact for wildfire records in the Alabama Forestry Commission. Received records for [email protected] wildfires and prescribed fires that occurred on the state and private lands in Alabama for year 2000. 174 Mississippi Randal Romedy 601-359-2823 Forestry Commission Florida Division of Forestry Sue McLellan 850-414-8554 Southern Area Coordination Randy Dzialo 770-458-2464 770-458-6308 Center [email protected] This is the person to contact for wildfire records in the Mississippi Forestry Commission. Received information that records for wildfires that occurred both on state and federal lands in the state of Mississippi in the year 2000 are available in GIS format. Submitted written request for wildfire records for year 2000 and records were not yet received. [email protected] This is the person to contact for wildfire records in the Florida Division of Forestry. Submitted written request for wildfire records for year 2000 and records were not yet received. [email protected] This is the person to contact for wildfire records in the Southern Area Coordination Center (SACC). This center reports the wildfire incidents in 13 southern states, Puerto Rico and Virgin Islands to the National Interagency Coordination Center (NICC). For more information on SACC, http://www.southernregion.fs.fed.us/sacc/. This person informed that this center doesn't maintain detailed wildfire records on a daily basis and can provide only the total number of fires and total acreage burned for year 2000. He recommended to contact the individual state forest departments, USDA Forest Service, and NICC. 175 U.S. Department of Agriculture National Agricultural Statistics Service Mark Miller He confirmed that the databases at NASS do not include information about cropland burning. NASS databases list crop types by county 202-720-7621 Texas Agricultural Burt Williams, 806-659-4130 Extension Hansford Co. Agents (contacted by Mike Bragg, 806-244-4434 Dallam Co. phone) Vince Mannino, 409-835-8461 Jefferson Co. Mike McCown, 409-267-8347 Chambers Co. [email protected] He reports that <5% of irrigated wheat fields in this area are burned and that burning is unlikely on non-irrigated fields. [email protected] [email protected] He reports that buring of crop residues is uncommon in his area and occurs in winter. [email protected] He reports that there is minimal marsh burning near the coast in February and early spring. In the same period no more that 10% of hay fields are burned and that no rice fields are burned. The Anahuac Wildlife preserve sometimes burns coastal grasses to improve wildlife habitat. In the last 5 years the practice of burning crop residue has been decreasing due to changes in accepted practices and drought conditions. 176 [email protected] He reports that very little marsh grass is burned in his area and set the approximate amount at 5%. The marsh grasses that are burned are no more than 10-15 miles from the coast. He also said that no croplands are burned in his area. Brent M Batchelor, 979-245-4100 Matagorda Co. [email protected] He reports that crop burning is very rare and that coastal marsh grasses are sometimes burned, mainly in winter, most commonly in February. Ismaro Cardenas, Live 361-449-2733 Oak Co. [email protected] Donnie Montemayor, 361-362-3280 Bee Co. [email protected] Kelly R Boldt, 409-835-8461 Jefferson Co. Region 1 Panhandle (Amarillo) Texas Agricultural Armstrong Extension Offices Deaf Smith (contacted in Hemphill email Oldham survey) Wheeler Region 2 South Plains (Lubbock) Bailey Dawson Hockley [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] 177 Parmer Yoakum Region 3 Rolling Plains (Vernon) Archer Dickens Jack Motley [email protected] [email protected] Throckmorton [email protected] [email protected] [email protected] [email protected] [email protected] Region 4 North (Dallas) Bowie [email protected] Dallas Grayson Morris Titus Region 5 - East (Overton) [email protected] [email protected] [email protected] [email protected] Anderson [email protected] Henderson [email protected] Newton [email protected] San Augustine [email protected] Upher [email protected] 178 Responded to email questionnaire by telephone. Indicated that about 4% of crop residue from wheat fields is burned, usually in June, and that <1% of rangelands are burned in the county. Region 6 - Far West (Ft. Stockton) Andrews Ector [email protected] [email protected] Jeff Davis [email protected] Presidio Val Verde Region 7 West Central Brown Concho Llano Nolan Sterling Region 8 Cenral Bell Elleis [email protected] [email protected] Hill Country [email protected] McLellan [email protected] Willaimson [email protected] Region 9 Southeast (Bryan) Brazos Grimes Liberty [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] 179 Walker Region 10 Southwest (Uvalde) Aransas Caldwell [email protected] [email protected] [email protected] Guadalupe [email protected] Kinney Uvalde [email protected] [email protected] Regioin 11 Coastal Bend (Corpus Christi) Texas Department of Agriculture Bee Goliad Nueces Wharton Region 12 South (Weslaco) [email protected] [email protected] [email protected] [email protected] Atascosa [email protected] Frio Kleberg Starr Zavala [email protected] [email protected] [email protected] [email protected] The Texas Department of Agriculture keeps no records of cropland or rangeland burning. 512-339-2929 180 Texas Department of Agriculture TNRCC Regional Affairs TAMU Academy for Ranch Management TAMU Agricultural Research Station Sonora Kerr WMA The Texas Department of Agriculture keeps no records of cropland or rangeland burning. 512-339-2929 He oversees a 10 county area and reports that he is not aware of any cropland burning in his area. He mentioned the rangeland burning of salt marshes near the Gulf Coast in winter. Patrick Derek Eads 409-898-3838 He reports that cropland and rangeland burning is very rare. Dr. Ray Hinnant 979-845-5580 Texas A&M researcher recommended contacting Dr. Butch Taylor for information about rangeland burning. 915-387-3168 Dr. Taylor is a proponent of rangeland burning and leads the Edwards Plateau Prescribed Burning Association. He reports that the interest in prescribed rangeland burnig has increased, but that drought conditions have prevented its practice from becoming much more common. There has been some increase in burning for Ashe Juniper control on the Edwards Plateau. Dr. Butch Taylor He reports that most prescribed burns occur in the winter (Dec. - Feb.); hot summer burns are rare and should not occur during drought conditions. Donnie Freds Texas A&M University Reference Guide for Texas Ranchers Website outlines accepted practices for http://texnat.tamu.edu/ranchref/guid rangeland prescribes burns. e/rwabc.htm 181 Newspapers Contacted for Fire Information Lake Charles American Press, LA The Advocate Baton Rouge, LA The Daily Advertiser Lafayett, LA Deridder Daily News Deridder. LA The Shreveport Times Shreveport, LA Austin American Statesman Austin, TX Beaumont Enterprise Beaumont, TX The Examiner Beaumont, TX Dallas Morning News - Dallas, TX Houston Chronicle Houston, TX Houston Chronicle - http://www.americanpress.com/ http://www.theadvocate.com/ http://www.theadvertiser.com/news http://www.deridderdailynews.com/ http://www.nwlouisiana.com/ http://www.austin360.com/aas/ http://www.southeasttexaslive.com/ site/news.asp?brd=2287 http://www.theexaminer.com/ http://web.lexis-nexis.com/universe http://www.chron.com/ http://web.lexis-nexis.com/universe 182 Houston, TX Times-Picayune - New Orleans, LA The Daily Sentinal Nacogdoces, TX http://web.lexis-nexis.com/universe http://www.dailysentinel.com/ 183