ASSESSMENT OF ENERGY CONSIDERATION IN THE DESCRIPTION OF HYDROLOGICAL PROCESSES MODELING

Abstract

Both land surface models and hydrological models use similar algorithms to describe water movement phenomena such as surface, sub-surface, ground water, etc, at a point. The fundamental difference between two schemes lies in evaporation estimation. Land surface models simulate actual evaporation using the energy balance whereas hydrologic models estimate evapotranspiration from the potential evaporation considering soil and plant properties such as soil moisture variation, leaf area index (LAI), plant root distribution, plant root depth, etc. This paper compares the performance of the land surface model developed at NCAR (LSM) and the hydrological model developed at IIS, University of Tokyo (IISDHM) against field observations from a hydro-meteorological observations (at 10 minutes interval) in an urban catchment. Both the LSM and IISDHM were able to simulate soil moisture variation adequately. Their long term evaporation estimates agree even though the short term patterns are different.