Droughts analysis for the 20 and 21st century Presented by: Dr. Gerald Corzo In Cooperation with WATCH project.

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.