Civil and Environmental Engineering Hydrologic modeling and prediction at continental scales: Model development and applications Dennis P. Lettenmaier Civil and Environmental Engineering CEE 500 Seminar December 2, 2004
Outline of this talk “Who we are, what we do” Macroscale hydrologic model development and testing Selected model applications Arctic hydrology Historic drought analysis Westwide hydrologic forecasting
LAND SURFACE HYDROLOGY RESEARCH GROUP 2004 Jenny Adam Ali S. Akanda Kostas Andreadis Ted Bohn Elizabeth Clark Mariza Costa-Cabral Su Fengge Alan Hamlet Jordan Lanini Dennis Lettenmaier Nathalie Voisin Andrew Wood Seung-Oh Yu Qianru Zeng Chunmei Zhu
2) Macroscale hydrologic model development and testing
Variable Infiltration Capacity (VIC) Macroscale Hydrology Model
Investigation of forest canopy effects on snow accumulation and melt Measurement of Canopy Processes via two 25 m2 weighing lysimeters (shown here) and additional lysimeters in an adjacent clear-cut. Direct measurement of snow interception
Calibration of an energy balance model of canopy effects on snow accumulation and melt to the weighing lysimeter data. (Model was tested against two additional years of data)
Summer 1994 - Mean Diurnal Cycle Point Evaluation of a Surface Hydrology Model for BOREAS SSA Mature Black Spruce NSA Mature Black Spruce SSA Mature Jack Pine -100 100 300 Rnet -50 50 150 250 H 60 120 LE 3 6 9 12 15 18 21 24 Rnet H LE 3 6 9 12 15 18 21 24 Rnet H LE 3 6 9 12 15 18 21 24 Flux (W/m2) Local time (hours) Observed Fluxes Simulated Fluxes Rnet Net Radiation H Sensible Heat Flux LE Latent Heat Flux
Range in Snow Cover Extent Observed and Simulated Eurasia North America J F M A S O N D Month Observed Simulated 4 8 12 16 20 snow cover extent (10 6 km 2 ) 10
UPPER LAYER SOIL MOISTURE June 18th-July 20th, 1997 UPPER LAYER SOIL MOISTURE 0.40 0.10 0.20 0.30 SOIL MOISTURE (%) X TOPLATS regional ESTAR distributed TOPLATS distributed 11:00 CST JULY 12 1997 ESTAR TOPLATS 50 10 11:00 CST JUNE 20, 1997 Illinois soil moisture comparison
Mean Normalized Observed and Simulated Soil Moisture Central Eurasia, 1980-1985 20°E 30°E 40°E 50°E 60°E 70°E 80°E 90°E 100°E 110°E 120°E 130°E 140°E 40°N 50°N 60°N A B C D E F G H 100 200 Soil Moisture (mm) J M S O N Normalized Observed Simulated
Cold Season Parameterization -- Frozen Soils Key Observed Simulated 5-100 cm layer 0-5 cm layer
3) Selected model applications
a) Arctic hydrology
b) Continental U.S. drought analysis
c) Westwide hydrologic forecasting
Ongoing/planned work Arctic freshwater balance reconstruction and trend attribution Westwide forecast applications – extension to include assimilation of remote sensing data (esp. snow cover extent), increased forecast frequency (to weekly updates), inclusion of shorter lead times (7-14 days) Drought recovery analysis Global applications (and linkage with surface water mission proposal)