Development of the Global Hydrologic Model with Advanced Characterization of Subsurface Transport Processes for Water Availability Assessment
Abstract
The key uncertainties in daily to long-term projections of water cycle variables and the advances in regional to global models are addressed in this study. The global hydrologic model is developed with enhanced spatial and temporal resolution, physical complexity, hydrologic theory and processes. Coupled with the Common Land Model (CLM), a 3-dimensional volume averaged soil-moisture transport (VAST) model is expanded to incorporate the lateral flow and subgrid heterogeneity. The model consists of 11 soil-hydrology layers to predict lateral as well as vertical moisture flux transport based on Richard's equations. The primary surface boundary conditions (SBCs) include surface elevation and its derivatives, land cover category, sand and clay fraction profiles, bedrock depth and fractional vegetation cover. A consistent GIS-based database is constructed for the SBCs of the model from existing observational databases with various resolutions, map projections and data formats. Surface dataset is prepared to run the model at 30 km scale for the global domain in Lambert Azimuth Equal Area projection. Global ECMWF data at 6-hour time steps for the period 1995 through 2000 is processed to get the forcing data which includes incoming longwave and shortwave radiation, precipitation, air temperature, pressure, wind components, boundary layer height and specific humidity. Extensive processing of data is done to convert the forcing data to specific model format at 30-minute time intervals. Initial results for selected basins in North-America and Asia demonstrate the effectiveness of the coupled CLM-VAST model. The simulation results show that the lateral and subgrid fluxes play a significant role in total soil-moisture dynamics. In the future, this model will be coupled with a basin water management model to assess water availability.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFM.H43A0475B
- Keywords:
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- 1832 Groundwater transport;
- 1833 Hydroclimatology;
- 1836 Hydrological cycles and budgets (1218;
- 1655);
- 3322 Land/atmosphere interactions (1218;
- 1631;
- 1843);
- 3337 Global climate models (1626;
- 4928)