TALLER DE GESTION INTEGRADA DE RECURSOS HÍDRICOS

QUITO19 Junio 2006

Vicente Barros

LAS PREVISIONES PARA LA GESTILAS PREVISIONES PARA LA GESTIÓÓN DE LOS RECURSOS N DE LOS RECURSOS HHÍÍDRICOS EN RELACIDRICOS EN RELACIÓÓN CON N CON

LA VARIABILIDAD Y EL CAMBIO CLIMLA VARIABILIDAD Y EL CAMBIO CLIMÁÁTICO TICO EN LA CUENCA DEL PLATAEN LA CUENCA DEL PLATA

PROGRAMA MARCO PARA LA GESTION PROGRAMA MARCO PARA LA GESTION SOSTENIBLE DE LOS RECURSOS HIDRICODS SOSTENIBLE DE LOS RECURSOS HIDRICODS

DE LA CUENCA DEL PLATA EN RELACION DE LA CUENCA DEL PLATA EN RELACION CON LOS EFECTOS HIDROLOGICOS DE LA CON LOS EFECTOS HIDROLOGICOS DE LA VARIABILIDAD Y EL CAMBIO CLIMATICOVARIABILIDAD Y EL CAMBIO CLIMATICO

ComitComitéé Intergubernamental de la Cuenca del PlataIntergubernamental de la Cuenca del Plata

WHY WHY INTEGRATE CLIMATE CHANGEINTEGRATE CLIMATE CHANGE

IN THE PLATA BASIN PROGRAME?IN THE PLATA BASIN PROGRAME?

12

3

4

5

6

1: Chaco

2: Pantanal

3: Middle Paraguay

4: Upper Paraná

5: Middle Paraná

6: Upper Uruguay

Changes in river dischargesChanges in river dischargesRío de la Plata basin

Paraná River - Corrientes

annu

al d

isch

arge

(m3 /s

)

0

5000

10000

15000

20000

25000

30000

35000

40000

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Uruguay River- Paso de los Libres

annu

al d

isch

arge

(m3 /s

)

0

2000

4000

6000

8000

10000

12000

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Salado River - RP 70

annu

al d

isch

arge

(m3 /s

)

0

100

200

300

400

500

600

700

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Paraguay River - Puerto Bermejo

annu

al d

isch

arge

(m3 /s

)

0

2000

4000

6000

8000

10000

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

•• Are the river flow changes Are the river flow changes resulting from precipitation resulting from precipitation changes or from the land use changes or from the land use change?change?

Land surface effects

Land cover / Land use

¿ How much of the changeshould be attributed

to precipitation changeand how much to land use change?

Precipitation en the Plata basin (m3 s-1)

Streamflow(m3 s-1)

Evaporation +Infiltration (m3 s-1)

1998 107000 36600 70400

1999 81600 20440 61600

Difference 23 % 44 % 13 %

El Niño 76000 25250 50750

La Niña 71000 21640 49360

Difference 7 % 17 % 3 %

1951-1970 72000 19300 52700

1980-1999 83500 26000 56500

Difference 16 % 35 % 9 %

AMPLIFICATION OF THE PRECIPITATION VARIABILITY IN THE RIVER FLOWS

PRECIPITATION CHANGES

Annual precipitation trends 1900-2000

IPCC (2001)

SE South America: 23%Chile: 40%

pm

m

600

800

1000

1200

1400

1600

1800

2000

2200

2400

1940 1950 1960 1970 1980 1990 2000

Monte Caseros: Annual Precipitation

Annual rainfall trends (mm/year): 1960-2000

The region hasincrements in the annual rainfallbetween 10% and 40%.

The increments in some regions of the Plata basinwere 200 m or more in 40 years.

IMPACTS-70 -65 -60 -55 -50 -45 -40-40

-35

-30

-25

-20

-15

Isohyets in Isohyets in mmmm

black : black : 19501950--19691969

Red:Red:19801980--19991999

Extreme events

Number of cases with Precipitation> 100 mm/(2 days) for 16 gauging stations over

central and northeastern Argentina

0

5

10

15

20

25

30

35

40

59/ 62 63/ 66 67/ 70 71/ 74 75/ 78 79/ 82 83/ 86 87/ 90 91/ 94 95/ 98 99/ 02

AÑOS

Precipitation over 150 mm: rate between the annual frequency of the 1983/2002 and the 1959/1978 periods

Impacts in the HydrologyImpacts in the Hydrology

Annual maximum, mean and minimum daily discharge of the Paraná river at Santa Fe-Paraná

period 1902-2000

0

10000

20000

30000

40000

50000

60000

Cau

dal (

m3/

s)

1910 1940 1970 2000

1997/98 Flood of the Paraná River(Satellite images from CONAE)Normal conditions

TEMPERATURE

Global annual temperature trends: 1976-2000

IPCC (2001)

CLIMATE CHANGE CLIMATE CHANGE SCENARIOSSCENARIOS

Average of various models: Mean annual temperature difference 2071/ 2100 minus 1961/ 1990 (colors),range (blue lines) (in °C). (IPCC, 2001)

-80 -75 -70 -65 -60 -55 -50 -45-60

-55

-50

-45

-40

-35

-30

-25

-20

-80 -75 -70 -65 -60 -55 -50 -45-60

-55

-50

-45

-40

-35

-30

-25

-20

-80 -75 -70 -65 -60 -55 -50 -45-60

-55

-50

-45

-40

-35

-30

-25

-20

HADCM3 model HADCM3 model Scenario A2 :Scenario A2 :Difference of Difference of temperature (temperature (°°K) K) with present with present (1961(1961--90)90)

2020/2030 2050/2060

2070/2080

In the La Plata Basin, temperatures will be higher and rainfall will tend to be above normal or not as projected by all IPCC models, especially for the time slices between 2050 and 2080. Courtesy of Marengo

PrecipitationTemperature

LPB temperature and precipitation scenarios for 2050-2080

Hydrologic modeling

Discharge Scenarios: Plata Basin

-5112,627-2120,31126,012Total

-472,836-194,2935,329UpperUruguay

-564,541-237,99310,435MiddleParaná

-364,230-155,6526,614UpperParaná

-72691-341,5122,435Paraguay

-73329-377601,202Pantanal

+ 5° CPercent change

+ 5° CEstimated

m3/s

+ 2° CPercent change

+ 2° CEstimated

m3/sPresent

dischargem3/s

IN THE PLATA BASIN75 % OF PRECIPITATION EVAPORATES

ONLY 25 % REACH the RIVERS

RELATIVELY MODEST CHANGES IN PRECIPITATION OR IN EVAPORATION MAY LEAD

TO GREAT PERCENT CHANGES IN THE RUNOFF

IN THE CONTEXT OF CLIMATE CHANGE THIS MEANS THAT THE

HIDROPOWER (BRASIL 90 %)NAVEGATIONWATER SUPPYARE HIGHLY VULNERABLE

Hay Cambio Climatico?THE BEST GLOBAL CLIMATE MODELS DO NOT

REPRODUCE THE MAIN FEATURES OF

PRECIPITATION AND TEMPERATURE OVER THE

PLATA BASIN

Verification of rainfall fields

-65 -60 -55 -50 -45

-45

-40

-35

-30

-25

-20

-15

-10PP HADCM3-UDEL - ANNUAL (1961-1999) (mm/dy)

Difference between observed annual precipitation and

simulated by the HADCM3 model (mm/day)

~ 35 % lower than observed

PART OF THE PROJECTED CLIMATE CHANGE IS PART OF THE PROJECTED CLIMATE CHANGE IS UNAVOIDABLEUNAVOIDABLE

IT IS ALREADY TAKEN PLACEIT IS ALREADY TAKEN PLACE

REGIONAL CLIMATE PROJECTIONS HAVE LARGEREGIONAL CLIMATE PROJECTIONS HAVE LARGEUNCERTAINTIESUNCERTAINTIES

SOCIETY NEEDS BETTER PROJECTIONS TO START SOCIETY NEEDS BETTER PROJECTIONS TO START ADAPTATIONADAPTATION

GOVERMENTS NEED BETTER PROJECTIONS TO ASSESS GOVERMENTS NEED BETTER PROJECTIONS TO ASSESS THEIR NATIONAL INTERESTSTHEIR NATIONAL INTERESTS

Land surface effects

Land surface effects

Climate changescenarios

Climate changescenarios

Extreme eventsExtreme events

Hydro-climatePrediction

Hydro-climatePrediction

La Plata Basin Priority areas

Variability and trends

Variability and trends

Planned activities

• Climate change scenarios, vulnerability and adaptation

. Land use change

. Improvement of the diagnostic and prediction system (weather and climate)

• Improvement of the diagnostic and prediction system (hydrology)

• Enhanced monitoring

• Field experiment

Thank you!...