Development of a Macro-Scale Land-Surface Hydrologic Model for General Circulation Models.

摘要

The development and evaluation of a macroscale land surface hydrology model, appropriate for inclusion into atmospheric general circulation models (AGCMs) is presented. The model includes hydrologically important processes such as base flow, infiltration capacity characteristics and spatial variability in soil and runoff parameters. The model, referred to as the Variable Infiltration Capacity (VIC) model accounts for sub-grid heterogeneity in land characteristics, and represents four major hydrologic processes. These are: (1) infiltration that varies spatially within the grid or catchment and temporally depending on the soil moisture; (2) runoff that depends non-linearly with the catchment average soil moisture; (3) evaporation where the actual amount depends on the potential evapotranspiration and the soil moisture level, and (4) an interstorm base-flow parameter that is related to the soil moisture level. The results indicate that the VIC model reproduces the important hydrologic processes significantly better than the bucket model and is computationally efficient. The model could successfully be used as the land hydrology parameterization in current AGCMs. Future research will test the model within an AGCM in the short term.