p0507 [Compatibility Mode]

Z. Balint, Chief Technical Advisor
P. Muchiri, Meteorologist
FAO SWALIM
Somalia Water and Land Information Management System
Drought Monitoring and Mitigation in the Horn of Africa
Drought Monitoring and Mitigation
in the Horn of Africa
Are we prepared?
What
to do ?
Who
should do it?
How
to do?
Natural phenomena
Can we manage drought?
Impacts of drought
Mitigating the
impacts of drought
WHAT can we use?
Tools, measures, facilities
HOW can we use?
Response systems,
Preparedness
Drought Monitoring and Mitigation in the Horn of Africa
Integrated drought management
• Drought resistant crops
• Irrigation
• Storage systems
• Market systems
• etc.
HOW?
• Long term plans for
sustainable production
• Short term plans for
adaptation
• Rapid response plans for
mitigating the impacts
Long term trends
MONITORING
Real-time drought evolution
Early warning
Impacts
Drought Monitoring and Mitigation in the Horn of Africa
WHAT?
Food shortage caused
by drought or
env. degradation
Proper diagnosis is needed
for proper response
SOLUTION
(example)
LONG TERM
SHORT TERM
Relatively easy
to mobilise
“DROUGHT”
FUNDS
Food distribution
Local market price
down
Production stops
(incl. seeds)
More difficult
to get
Skills degrade
DEPENDENCY
SHORT +
LONG TERM
Based on
Measurements
& analysis
Proper identification:
Env. Degradation
•export charcoal prod
•plant degradation
•soil erosion
Altern. income generation
Land conservation
Land use planning
Farm development
SUSTAINABLE
SUPPLY OF FOOD
Drought Monitoring and Mitigation in the Horn of Africa
Why monitor drought?
Are we prepared?
Do we have the common understanding of drought?
Do we know what to observe and do we have the equipment for that?
Do we have monitoring systems?
Do we have methodologies how to interpret the observations?
Do we have the pre-set mechanisms, the standard procedures how to react
in a real emergency situation?
Do we know the measures, tools, how to mitigate the impacts of drought?
Do we have long term visions how to adapt the production system to show
more resilience to drought?
There is a long way to go.
We can start with better understanding the drought and join our
efforts in developing methodologies for monitoring, forecasting and
mitigating its impacts.
Drought Monitoring and Mitigation in the Horn of Africa
Drought is a frequent, recurrent event in the Horn of Africa. - Despite its frequency
it always seems to be a surprise, causing an emergency.
What is drought?
disease
Crop failure
Animals die
hail, cold rain
disease
drought
overgrazing
Population growth
drought
Armed conflicts
market problems
Malnutrition
grows
Food shortage
armed conflicts
Market problems
drought
drought
Drought – short term (end foreseen) – temporary deviation
Land degradation – long term - difficult to reverse
Treatment is
much different
Drought Monitoring and Mitigation in the Horn of Africa
wrong crop type
Drought is an extended period, during which, fresh water
availability and accessibility for the ecosystem at a given time
and place is below normal, due to unfavourable spatial and
temporal distribution of rainfall, temperature, soil moisture
and wind characteristics.
Serious anomaly - Long duration
Drought Monitoring and Mitigation in the Horn of Africa
What is drought?
•Rainfall
Rainfall amount
•Rainfall
Rainfall temporal distribution
•Soil
Soil moisture
•Soil
Soil moisture temporal distribution
•Temperature
Temperature
•Temperature
Temperature temporal distribution
•Wind
Wind characteristics
Drought Monitoring and Mitigation in the Horn of Africa
Drought factors in a given region are:
Drought indices analysed
Physical indices (water balance)
Palmer’s Drought indices, namely, Palmer Drought Severity Index ( PDSI),
Palmer Hydrological Drought Index(PHDI), Palmer Z-index (PZI) and Crop
Moisture Index (CMI)
Surface Water Supply Index (SWSI)
Reclamation Drought Index (RDI)
Statistical indexes (time series analysis)
Percent Normal Drought Index (PNDI)
Standardized Precipitation Index (SPI)
Precipitation Decile Index
Weighted Anomaly Standardized Precipitation (WASP)
Drought Monitoring and Mitigation in the Horn of Africa
How to measure the severity of drought?
precipitation
temperature
soil moisture
Combined effect
wind
Drought Monitoring and Mitigation in the Horn of Africa
Multiple parameter
Step 1: Three different, individual drought indices are calculated, each reflecting
the quantity deviation from LTM and the persistence of the deviation
 Actual length of cont deficit/ex cess in the IP 
Actual average for IP

DI =
* 
LTM for IP
 LTM length of cont deficit/ex cess in the IP 
Step 2: The combined effect is calculated in the CDI
CDI i ,m = wPDI * PDI i ,m− 2 + wTDI * TDI i ,m− 2 + wVDI *VDI i ,m
It is an index that measures how much the present conditions deviate
from the reference level, which is the multi-year long-term average for a
selected time duration (X dekads, Y months).
Drought Monitoring and Mitigation in the Horn of Africa
The SWALIM Combined Drought Index (CDI)
Temperature
drought index
Vegetation
drought index
PDI
TDI


j=0
* 
=
n  IP −1
 1

1
*

 ∑ P( m − j ), k 
∑
n
( n * IP ) k =1  j = 0

i ,m
i,m
VDI i ,m
=
1
IP
∑P
*
i ,( m − j )
∑ [T
IP − 1
j=0
*
i,( m − j )
]


1
*
T
∑  ∑ ( m − j ), k 
( n * IP ) k = 1  j = 0

n
IP − 1
*



1

 n


RL

n
( P *) 
RL
∑
m ,k ) 
k =1

( P *)
m ,i


RL

n
( T *) 
RL
∑
m ,k ) 
k =1

( T *)
m ,i
IP −1




( NDVI *)
RL
j =0
m ,i

* 
=
n
n  IP −1
1

( NDVI *) 
1
*
RL
)
 ∑
m ,k
 ∑ NDVI ( m − j ), k 
∑
n
 k =1

( n * IP ) k =1  j = 0

1
IP
∑ NDVI
*
i ,( m − j )
For more information please consult the CDI
brochure and the attached CDI calculator CD
Drought Monitoring and Mitigation in the Horn of Africa
Precipitation
drought index
IP −1
1
IP
Drought Monitoring and Mitigation in the Horn of Africa
Kenyan stations
4.5
Hargeisa
4.0
PDI
VDI
CDI
Threshold
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1982
1983
1984
1985
1986
1987
1988
1989
1990
NO DATA
2005
2006
2007
2008
2009
2010
5.0
Baidoa
4.5
PDI
VDI
CDI
Thres hold
4.0
DroughtIndex(-)
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1982
1983
1984
1985
1986
1987
1988
NO DATA
2004
2005
2006
2007
2008
2009
2010
6.5
6.0
Afgooye
PDI
5.5
VDI
CDI
Thres hold
DroughtIndex(-)
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1982
1983
1984
1985
1986
1987
1988
1989
1990
NO DATA
2005
2006
2007
2008
2009
2010
Drought Monitoring and Mitigation in the Horn of Africa
Drought Index(-)
3.5
Drought Monitoring and Mitigation in the Horn of Africa
Debrecen – Hungary, Europe
Year
Month
Kakamega
Kisumu
Lodwar
North
Kenya
Embu
Dagoretti
Mandera
1999
1999
10
11
1999
2000
2000
12
1
2
0.96
0.77
0.67
1.04
1.06
0.87
0.79
0.71
0.59
1.07
1.37
1.31
1.57
1.47
1.06
0.74
0.9
0.96
0.86
1.06
1.02
1
1.05
0.93
2000
2000
2000
3
4
5
0.42
0.34
0.49
0.68
0.51
0.49
0.42
0.46
0.64
0.49
0.63
0.5
0.33
0.31
0.58
0.52
0.51
0.34
0.61
0.62
0.89
0.56
0.51
0.56
2000
2000
6
7
0.63
0.75
0.61
0.82
0.31
0.32
0.25
0.33
0.45
0.99
1.53
0.64
0.86
2000
2000
2000
8
9
10
0.7
0.6
0.71
0.93
0.95
0.93
0.31
0.36
1.25
0.34
0.53
0.65
0.52
0.62
0.67
0.65
0.66
0.8
0.63
1.22
0.76
0.56
0.42
1.05
0.62
0.66
0.94
2000
2000
11
12
0.86
1.07
1.12
1.34
1.77
1.91
0.48
0.42
0.72
0.73
0.53
1.03
1
2001
2001
1
2
1.33
1.53
1.91
1.86
1.55
1.65
0.68
1.03
1.42
1.88
0.32
0.34
0.5
1.09
0.83
0.45
0.43
1.1
1.23
2001
3
1.14
1.3
1.7
1.34
2.57
0.85
0.61
1.36
0.6
0.69
Drought severity legend
Extre
me
Seve
re
Moderat
e
Mild
None
North East Kenya
0.88
0.9
0.65
0.78
County
Western Kenya
1.32
1.08
1
0.9
Central Kenya
0.46
1.05
0.81
1.21
Wajiir
0.89
0.87
Drought Monitoring and Mitigation in the Horn of Africa
CDI trends and comparison with drought reports
1
The CDI reflects: rainfall amount deficit and its critical duration
air temperature excess and its critical duration
NDVI deficit and its critical duration
It provides a time series of the indices that can be further analysed with
statistical methods
Further research is suggested on
• Howe to use it for short time early warning
• How to extent it from point data series to spatial analysis
Drought Monitoring and Mitigation in the Horn of Africa
SUMMARY CONCLUSIONS ON CDI
Somalia Water and Land Information Management System
Drought Monitoring and Mitigation in the Horn of Africa
Thank you for your attention