Modeling of land surface processes in La Plata Basin

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Modeling of land surface processes in La Plata
Basin
Fengge Su1, Dennis P. Lettenmaier1 Vicente R.
Barros2, Carlos E. M. Tucci 3 and Ernesto Hugo
Berbery4 1University of Washington, Seattle,
WA 2University of Buenos Aires, Buenos Aires,
Argentina 3Universidade Federal do Rio Grande do
Sul, Porto Alegre, Brazil 4University of
Maryland at College Park, College Park, Maryland
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Outline

• Background
• Model description
• Data sources
• Streamflow simulations
• Future research

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Background

• The La Plata basin is the sixth largest in the
  world, and spreads over five South American
  countries.
• It plays a critical role in economies and water
  resources of the region.

Bolivia
Brazil
Paraguay
Atlantic Ocean
Argentina
Uruguay
Lat -14-38 Lon -67-43 Area 3.1106 km2
Map From PLATIN
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Parana
Genta et al. (1998)

• Macroscale hydrology models provide a useful
  approach for understanding the nature and cause
  of these changes.

Paraguay
Uruguay
Negro
Precipitation (mm/year)
Barros et al. (2000)
How predictable is runoff in La Plata Basin, what
are the limiting factors, and what is the spatial
variability of the water balance terms?
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Model description

• Model features
• multiple vegetation classes in each cell
• energy and water budget closure at each time
  step
• subgrid infiltration and runoff variability
• and non-linear baseflow generation.

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Data sources

• Meteorological forcings
• Daily time series of precipitation, maximum
  
• temperature, minimum temperature, and
  wind speed
• Daily precipitation and temperature are
  from NCAR and GDCN (Global Daily Climatology
  Network) station data.
• wind speed is downscaled from the
  NCEP/NCAR reanalysis
• Land surface characteristics
• Soil parameters from Global Soil Data
• Products CD-ROM (IGBP-DIS)
• Land cover characterization based on
  University of Maryland 1-km global vegetation
  classifications.

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• Precipitation stations for 1986 (2050)
• Poor coverage areas Paraguay basin and Lower
  basin of the Parana River.

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• Temperature stations for 1986 (125).
• Stations are sparse for the whole basin.

Paraguay
Parana
Uruguay
Lower Basin
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VASClimO (Variability Analysis of Surface Climate
Observations) gridded monthly half-degree
precipitation.
Mean monthly precipitation (this study)
1979-1999
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Uruguay
Parana
Paraguay
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Streamflow simulations

• Study area the whole La Plata Basin
• Model options with full energy balance
• Model resolution 1/8 degree
• Time step 3-hour

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La Plata Basin River Network at 1/8 degree
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Mean Monthly Streamflow (1979-1999)
Parana at Jupia Area478,000km2
Paraguay
Paraguay at Bermejo Area 1,100,000km2
Parana
Uruguay
Iguazu at Estreito Area63,236km2
Parana at Posadas Area975,000km2
Uruguay at Paso de los Area189,300km2
Simulated
Observed
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Monthly time series of streamflow (1979-1999)
Uruguay
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Parana
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Observed
Simulated
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Simulated mean monthly runoff for the entire La
Plata basin (1979-1999) Runoff ratio (R/P) for
the three subbasins Uraguay 0.44 Parana
0.32 Paraguay 0.14
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Next step research

• Overall goal is to estimate the effects of local
  ( e.g., vegetation) vs. remote (e.g., sea
  surface temperature) forcings on the
  precipitation and streamflow of La Plata Basin by
  a set of uncoupled or coupled runs (The Eta
  model, coupled with VIC and a river routing
  scheme).

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Thank you!