I.8. Estimación de la demanda hídrica

CIRCLE‐2 SHARE Workshop
Responses to Extreme Water
related Events
UPCT
‘Strategies for coping with extreme events in
irrigated agriculture. Some results from case
studies in Southern Spain’
Alain Baille
Universidad Politécnica de
Cartagena (UPCT)
Our working group has to debate on how to secure
and promote resilience of food and water systems
In this presentation:
Weather Extremes vs Irrigated
Agriculture
1 – Response and vulnerability of irrigated
crops to extreme heat events
2 – Some findings from case-studies in
Southern Spain (Campo de Cartagena)
Introduction
Despite improvements in technology and crop yield
potential, food production remains highly dependent
on climate, because solar radiation, temperature, and
precipitation are the main drivers of crop growth.
The relevance of weather extremes in agricultural
production and food security is now well-recognized (Lobell
et al., 2009, Science) and constitutes one of the priorities
of the next IPCC Assessment Report (AR5)
AR5: More regional, more extremes
•
•
•
•
Regional atlas
Regional phenomena chapter
Regional modelling chapter
SREX Special Report on
Extremes (Nov 2011)
•
•
•
•
Improved GCMs
High time resolution
+ CORDEX (RCMs)
Decadal predictions
Introduction
The aim of this talk is to present the effects of extreme
temperatures and their impact on irrigated agriculture with
special focus on fruit trees and their response
… and on measures to improve the sustainability and
resilience of irrigated systems
Campo de Cartagena Irrigation Scheme
…illustrating with some examples
from case studies performed in
the irrigation scheme of Campo
de
Cartagena
(Murcia,
Southeastern Spain)
Greenhouses
C.R. CAMPO DE CARTAGENA
Area:
41.090 Ha
Allocation:
142 Hm3
Farmers:
9.444
Otros Invernaderos
Leñosos
5%
7%
Citricos
27%
Horticolas
61%
Citrus
Horticultural
Crops
6
Irrigated areas in the Segura River Basin
Campo de
Cartagena
REDSIM Inception Meeting, Athens, Greece, 9 March 2011. Presentation Alain Baille
PART 1
Response and Vulnerability of Irrigated Fruit
Crops to Weather Extremes
Relevant Weather Extremes in Irrigated Agriculture
The two extreme weather events to account for in Irrigated
Agriculture include:
- Spells of extreme (low or high) temperature, and
- Intense rains, leading to waterlogging, and in some
cases to crop failure (root anoxia due to excess water).
Relevant Weather Extremes in Irrigated Agriculture
As long as sufficient water is available to irrigate, severe
agricultural droughts are not the main issue
- However, in case of strong shortage or failure of the
water supply system, consequences could be serious
- This type of situation might be more frequent in the
future, as far as agriculture has often the lowest priority
in the allocation of water during prolonged drought,
Mean temperature provides only a partial view of
crops behaviour
With respect to the functioning
of vegetation and crop
systems, mean temperature is
not the most significant and
critical climate statistics to
examine.
More relevant climate
statistics involve thresholds
at the upper and lower tail of
the probability distribution
and information on the timing
of certain temperature
regimes.
The importance of phenological timing in crop response
Phenology, the science
that studies the timing of
flowering, leaf expansion
and fruit set, accelerates
when winter minimum
temperatures increase
From FAO Irrig. Drainage Paper,66, 2012
The importance of phenological timing in crop response
It is well known that fruit crops yields can be ruined if
(i) frost occurs during the flowering and pollination period
and
(ii) if a heat spell occurs during the fruit-set period (e.g.
common burning of walnuts)
Also, insects and disease infestations are more likely to
occur if winter cold exposure is not sufficient
Heat waves
Heat waves : represent a cross-cutting element in
vulnerability assessment. They are likely to become more
intense and frequent.
There is no objective and uniform definition of ‘‘heat
wave.’’ Heat waves are typically defined locally with
specific applications in mind
e.g.: a three-day heat wave that is hotter than 95% of
all previous 3-day heat waves.
Detection of heat waves
Based on daily seasonal 95th percentile of TX and TN
Schematic overview of heat wave detection. Summer 2006 TX and
TN for the station of Ankara, Turkey. Red areas characterize hot days
and nights. Red dotted frames indicate the three 2006 heat waves.
Kuglitsch et al., GRL, 2010
Heat waves
Nighttime and daytime heat waves have different impacts
More humid nighttime heat waves associated with
contamination (e.g. ozone, aerosols) in urban environments
(heat island effect) have deleterious effects on human
health (Heat wave of summer 2003 in part of Weatern
Europe, especially France and Italy).
Dry daytime heat waves associated with high vapour
pressure deficit can damage seriously some vital functions
of plants (e.g. photosynthetic apparatus), leading to yield
losses, and in some cases, to crop failure.
Heat waves: more intense, more frequent
In Mediterranean Countries…
Since the 1960s, the mean heat wave intensity, heat wave
length and heat wave number across the eastern
Mediterranean region have increased by a factor of 7.6 ±
1.3, 7.5 ± 1.3 and 6.2 ± 1.1, respectively.
Linear trend of HWI95 (ºC per decade)
Kuglitsch et al.,
GRL, 2010
…and in arid regions
Title of a local newspaper of Arizona, Sept 2012
“It's hot enough to boil water on the sidewalk”
2012 will go down in the record books as one of the hottest
summers in U.S. history. From coast to coast, extreme heat
and drought have ravaged the nation.
“For seven consecutive days, daily high temperatures at
Phoenix: climbed to the 44-46ºC range; smashing or tying alltime heat records”
“The same week, Phoenix set a temperature record at the other
end of the thermometer. The Valley scored three consecutive
nights of all-time “record high lows. The nighttime low
temperature was 33 ºC for three straight nights”.
More hot days, less cold days
Less frequent
cold spells
More hot days, less cold days
More hot days is not the only issue for farmers. A loss of
cold days has implications as well.
Can lead to substantial economic losses
For example, some economically important fruit and nut
crops grown require enough hours of cold temperature to
reach their maximum potential.
More hot days, less cold days
This is traditionally measured in the number of hours
experienced below a threshold, such as 7º C. The
number of these “chill hours” will decrease, potentially
affecting crops.
So, the production of high value fruits and nuts could be
in jeopardy unless efforts are made to develop cultivars
that require less winter chill or move orchards to higher
elevations
Chill hours needed
In the future, one may need to substitute fruit species that need
less chill hours (e.g. peaches for almonds) or develop new
cultivars that require less winter chill.
High Tº = non linear effects on yield
Economically important crops such as corn, soybean and
cotton are sensitive to temperature extremes, with many
crops showing a gradual increase in yield with mild warming
that quickly transitions to a steep decline once a threshold
temperature is passed.
These non-linear effects of climate change are critical,
yet have not always been taken into account in crop
models or when calculating the economic impact of climate
change.
Actually, the effects of heat waves on plant functioning are
even more difficult to predict than the effects of severe
droughts: a challenge for crop modellers.
High Tº effects on yield
Yields from these economically
important crops initially
increase when temperature
goes up, but then drop sharply
at higher values.
Redrawn from Schlenker and
Roberts. (2009) Proc. Nat. Acad.
Sci. v. 106 p. 15594.
Blue = Cold Air
Outbreaks
Green: Flood
Red: heat wave
Various sources, including Lobell etal
2009, CEC-500-2009-040-F.pdf;
westernfarmpress.com
Damage on California
Irrigated Crops
Insurance payouts
PART 2
Some learnings from Southern Spain studies
Three Case Studies
Case 1: Heat wave and water status of irrigated citrus
orchards
Case 2: Heat wave and net primary productivity/C sink of
irrigated citrus orchards
Case 3. A Growers’ Information System for Irrigators based
on weather forecast. Barriers to Adoption
Case Study 1: Heat waves and water status of irrigated citrus
orchards
FP7-SIRRIMED
PROJECT
(2010-13)
Period of observation: July 2009
■ Very severe heat stress conditions were
observed in Southern
summer 2009
Spain
during
■ Several heat spells were observed
during July, characterized by maximum
daily air temperature and air VPD
(vapour pressure deficit), close to 36ºC
and 5 kPa respectively
Well-irrigated 30
years orange trees
(LAI: ~ 4)
28th International Horticultural Congress, Lisbon, Portugal, August 2010
Sequential heat waves of July 2009, Orange Orchard,
Pozo Estrecho, Murcia
Day of month
38.4ºC
16.8ºC
Hour of day
Average monthly Tº = 25.85 ºc
August 2009, Orange Orchard, Pozo
Estrecho, Murcia
Day of month
33.1ºC
16.7ºC
Hour of day
Average monthly Tº = 25.67 ºc
Selection of two classes of sunny days
■ “No-stress Days”
■ “Stress Days”
Ta ,Max < 30ºC
Air VPDMax < 2 kPa
Ta ,Max > 34ºC
Air VPDMax > 3.5 kPa
4 days per class were selected. The average value of
the 4 days was calculated (“average” day)
28th International Horticultural Congress, Lisbon, Portugal, August 2010
RESULTS
40
35
Air Temperature
Ta
30
25
20
No-stress Day
Stress Day
15
00:00
04:00
08:00
12:00
16:00
20:00
Hour
6
No-stress Day
5
Stress Day
Air VPD
VPDa
4
3
2
1
0
00:00
04:00
08:00
12:00
Hour
16:00
20:00
28th International Horticultural Congress, Lisbon, Portugal, August 2010
RESULTS
250
Stress Day
LE (W m-2)
200
No-stress Day
Latent Heat
Flux LE (W m-2)
150
100
50
0
-50
40000:00
04:00
08:00
Stress Day
H (W m-2)
300
No-stress Day
12:00
16:00
20:00
Hour
200
Sensible Heat
Flux H (W m-2)
100
0
-100
00:00
04:00
08:00
12:00
16:00
20:00
Hour
28th International Horticultural Congress, Lisbon, Portugal, August 2010
RESULTS
Bulk stomatal conductance to water vapour, gw (mm s-1)
-1
gw (mm s )
6

LE
gw 
 C p VPD c
4
No-stress day
2
Stress day
0
00:00
04:00
08:00
12:00
16:00
20:00
Hour
28th International Horticultural Congress, Lisbon, Portugal, August 2010
July 2009, Evapotranspiration (W/m2)
Orange Orchard, Pozo Estrecho, Murcia
Day of month
532 W m-2
Hour of day
Case Study 1: Main learnings
In our case study, heat waves are concomitant to very high
VPD (dry air), increasing strongly the evaporative demand.
Citrus spp. cope with heat wave by setting a limit to
transpiration losses, imposing severe reductions in stomatal
conductance - and therefore CO2 exchange rate - during the
heat wave period.
Irrigated Citrus could face extreme temperature maintaining
an homeostatic behaviour of transpiration rate
Case Study 2: Heat waves and NPP/C-sink of irrigated citrus
orchards
FP7-SIRRIMED
PROJECT
RESULTS
Net Primary Productivity (NPP, gCO2 m-2 s-1)
0.6
No-stress day
CO2
-2 s-1
-2
m
NEE
(g
CO2
NPP (g
m s-1))
0.4
Stress day
0.2
0.0
-0.2
-0.4
00:00
04:00
08:00
12:00
16:00
20:00
Hour
Hour
28th International Horticultural Congress, Lisbon, Portugal, August 2010
20
Ratio NEE/ET
WUE (g L-1)
16
12
Not stressed
8
Heat
stressed
4
0
06:00
10:00
14:00
Hour
18:00
GPP = gross photosynthesis
Heat Wave
July 2009, Agrosystem respiration (mol m-2 s-1)
Orange Orchard, Pozo Estrecho, Murcia
Day of month
132 kg(CO2) ha-1
Hour of day
2011
C-sink = -3.85 T(C) y-1
Temperate forests
Irrigated Citrus
Case Study 2: Main findings
Heat waves reduce strongly NPP of irrigated Citrus trees
In the climatic conditions of the Murcia Region, the Ccapture of a citrus orchard is ca 4 T(C) per ha per year,
similar to the C-sink of temperate forests.
Our results suggest that future increases in heat wave
number, duration and intensity might lead to substantial
reduction of C-sequestration, and to a lower contribution of
vegetation to the mitigation of greenhouse-gases impact.
Case Study 3: A weekly forecast bulletin for
irrigation scheduling
EU-DGE-REDSIM
PROJECT
(2011-2012)
See poster of
Hunink et al., this
workshop
The REDSIM advisory bulletin for irrigation scheduling
-Weekly irrigation advisory bulletin (REDSIM bulletin)
developed together with end-users
- Embodies different pieces of up-to-date information
provided by the REDSIM Information System into a single
document to support farmers in their weekly decisions on
irrigation planning,
- Participatory approach: A formative evaluation procedure
was applied to obtain farmers’ feedback on the advisory
bulletin during the design and trial run of the bulletin. Farmer
feedback was later used to improve the design of the
bulletin in order to enhance its usability.
REDSIM BULLETIN IS AN
OUTPUT OF THE
REDSIM INFORMATION
SYSTEM
Soil/crop Model
Expert recommendations
On-farm
information
Model
outputs
REDSIM
REDSIM BULLETIN
Weather data,
ET maps
Calibration,
model runs
Users Interface
Expert
interface
IMIDA server
UPCT Toolbox
REDSIM Bulletin
The bulletin provides
(i) 1-week weather forecasting information, including
forecasted crop water demand
REDSIM Bulletin
(ii) options for irrigation dose and frequency to meet the
forecasted demand, and their impact on water losses
and crop-available soil water,
REDSIM Bulletin
Synthesis
previous
week
Synthesis
annual
scale
(iii) Comparative
reference
information on
applied irrigated
amounts compared
to optimal local crop
water requirements.
Main findings of Case Study 3: Grower’s feedback
1 – Farmers appreciate the diagrams in which actual and
recommended irrigation levels were compared. The diagrams
reporting irrigation forecasts were found less useful.
2 - Some irrigators are reluctant to follow the recommended
irrigation level in the bulletin because the estimation did not
account for salinity and water quality
3 - Not all irrigators have a good grasp of scientific terms
such as ET0 or minimum available water capacity.
4 - Irrigators would prefer the information to be more
specific or tailored to their farm.
Case Study 3: Barriers to adoption
1 - “Local” and farm-specific information is desirable
Need to invest in sensors
2 - The degree of acceptance is proportional to the
farmers’ knowledge of processes (ET, soil water
balance…)
Need to invest in farmers’ formation and training
3 - Supplementary decision rules should be incorporated
The designers should account for soil salinity and water quality
Strategies to Cope with Extreme
Events in Irrigated Agriculture…
Thanks for your attention…