Droughts analysis for the 20 and 21st century
Presented by:Dr. Gerald Corzo
In Cooperation with WATCH project
Esta presentacion y su contexto en el taller
Donde?Cuando va a ocurir?Hay posibilidades de que eventos ocurran al mismo tiempo (sincronismo)?Puedo identificar con tiempo los cambios y poder pronosticar la magnitud?Como puedo reducir la incertidumbre de las proyecciones globales.?
Conocemos indudablemente que
hay cambios en frecuencias de los
eventos
Conocemos indudablemente que
hay cambios en frecuencias de los
eventos
Sabemos que van haber mayores duraciones de
sequias
Sabemos que van haber mayores duraciones de
sequias
Sabemos que los eventos seran mas
intensos……
Sabemos que los eventos seran mas
intensos……
Main objective:
to advance our knowledge of the impact of global change on hydrological extremes (drought & large-scale floods)
What are the characteristics of extreme historical events?
Are there consistent patterns in the spatial occurrence of extreme events?
Are we seeing an increase in the frequency and severity of extreme events?
What about the future (21st
century)?
Drought last decade (EEA, 2010)
Hydrological Extremes at a global scale: historic and
future climate
DATA OBSERVATIONS
- Test Basins
- Discharge data from the UNESCO-FRIEND European Water Archive
- WATCH Forcing Data (WFD, global, 0.5o, 20th century, Int. GPCC, ER40 and CRU) MODELING OUTCOME
- WATCH Test Basins, RBHMs
- WATCH Forcing Data (global, 0.5o, 21st century)
- Large-scale models: GHMs, LSMs (WFD, global, 0.5o, 20th century)
- Large-scale models: GHMs, LSMs (global, 0.5o, 21st century , 3 GCMs, A2 and B1)
Hydrological Extremes at a global scale: historic and
future climate
Large scale-data
Large-scale models
- GHMs
- LSHMs
0.5° x 0.5°
(sub)daily
HTESSEL
WaterGap
H08
GWAVA
VIC ?
Jules
LPJml
MPI-HMOrchidee
courtesy: WaterMIP
Spatial-temporal patterns (non-continuous areas)
Simulated runoff large-scale modelFixed threshold (X70, X80, X95)Drought characteristics per cell (67420 cells)Area in drought (globe, selected regions)
Tallaksen et al. (2009)
Algorithms that identify hydrological drought characteristics:
Example of the variable threshold and its moving average
0 100 200 300 400 500 600 7000
20
40
60
Days
Qsb
thre
sho
lds
WATERGAP smoothed thresholdl results 20th
Time series
100 200 300 400 500 600 700 800 900 10000
2
4
6
8x 10
-6
Time step (days)
Qsb
(kg
/ m
2 s) Threshold
Qsb model results
50 100 150 200 250 300 350 400 450-2
0
2
4
6
8x 10
-6
Time step (days)
Qsb
(kg
/ m2 s
)
50 100 150 200 250 300 350 400 450-5
0
5
10
15x 10
-5
Def
icit
volu
me
Daily intensity
No deficit ends after some time steps
Spatiotemporal pattern of droughts
Experimental options
RDI = River flow RSPI = RainfallDrought Catalogue (observed data)
Hannaford et al. (2011) Hydrol. Process.
Hydrological Extremes at a global scale: historic and
future climate
Hydrological Extremes at a global scale: historic and future climate
Number of droughts:
• drought in monthly runoff
• 8 large-scale models
• 1963-2001
• WATCH Forcing Data
Van Huijgevoort et al.
(under progress)
Spatiotemporal pattern of droughts
IntegrateTime seriesSpatial phenomena
Time Space
Drought characteristics
Probability of continuous drought events
Clustering
Spatial characterization of patterns in periods of timeClassification (Label events)
Non-continuous drought areas
January 30, 1963 WaterGap, subsurface flow (Qsb)
Non-continuous drought areas
Area in drought (globe)
0 50 100 150 200 250 300 3500.12
0.14
0.16
0.18
0.2
0.22
0.24
0.26
0.28
0.3
0.32
Day
Pe
rce
nta
ge
of a
rea
in d
rou
gh
t
WATERGAP - Qsb 80
2000199919981991
Non-continuous drought areas
Regionalization based on climatology
WFD classification version prepared by Niko Wanders
0 50 100 150 200 250 300 350
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Day
Pe
rce
nta
ge
of a
rea
in d
rou
gh
t
WATERGAP - Qsb 80 - Koppen Geiger region (Cfb)
2000199919981991
Non-continuous drought areas
Af climate (Tropical areas)
Cfb climate (e.g. Europe)
0 50 100 150 200 250 300 3500
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
Day
Pe
rce
nta
ge
of a
rea
in d
rou
gh
t
WATERGAP - Qsb 80 - Koppen Geiger region (Af)
2000199919981991
1997 1998
1976
Area in drought (hydro-climatic region)
Non-continuous drought areas
Af climate (Tropical areas) Cfb climate (e.g. Europe)
Temporal evolution of drought Percentage of drought per region (WaterGap 1963-2000)
Changes in time of drought regions
Synchronicity in drought occurrence
Van Huijgevoort, Hazenberg et al. (under progress)
Drought clusters:
• Drought in runoff
• August 1976
• WaterGAP
• WATCH Forcing Data
Hydrological Extremes at a global scale: historic
and future climate
Number of Droughts:
• Drought in runoff
• MPI-HM
• Impact climate change
• CNRM A2 projection
CTRL 1971-2000
2021-2150
2071-2100
Corzo, van Lanen et al. (under progress)
Hydrological Extremes at a global scale: historic
and future climate
Hydrological Extremes at a global scale: historic and future climate
Number of Droughts:
• Drought in runoff
• Impact climate change
• 3 GCMs
• A2 and B1 projection
Corzo, van Lanen et al. (under progress)
(a) MPI-HM (b) Ho8
Hydrological Extremes at a global scale: historic and future climate
Concluding remarks:
Characteristics of drought events is an important measure to determine overall changes in time series and their spatial distribution
Even have spatial discrepancy among models are clear it is possible to improve modelling ensembles by comparing their members ability to represent certain regions.
Characterization of global modelling representation of drought events has been done, however, work is needed on the classification of such results
Analysis of global information points to a similar patterns in some regions that allow for a detailed continental and regional investigations
Although floods is not presented in this work the analysis of their changes is being compared with the droughts.