Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: 1/6/2009
Publication Date: 1/20/2009
Citation: Wang, L., Koike, T., Yang, K., Jackson, T.J., Bindlish, R., Yang, D. 2009. WEB-DHM: A distributed biosphere hydrological model developed by coupling a simple biosphere scheme with a hillslope hydrological model [abstract]. American Geophysical Union, Fall Meeting Supplements. 89(53):H32D-08.
Technical Abstract: The coupling of land surface models and hydrological models potentially improves the land surface representation, benefiting both the streamflow prediction capabilities as well as providing improved estimates of water and energy fluxes into the atmosphere. In this study, the simple biosphere model 2 (SiB2) with advanced physics, and the geomorphology-based hydrological model (GBHM) with spatially-distributed structure and physical runoff and river routing schemes, have been selected to develop a new distributed biosphere hydrological model incorporating subgrid topography, which is referred to as the water and energy budget-based distributed hydrological model (WEB-DHM). The coupled model can give consistent descriptions of water, energy and CO2 fluxes at a basin scale. By using comprehensive field observations from the Southern Great Plains Hydrology Experiments (SG97 and SGP99), the WEB-DHM has been rigorously evaluated in the Little Washita Basin. For the SGP97 period, the model was calibrated and it shows an ability to reproduce point-scale water and energy balances as well as CO2 flux. At basin-scale, the WEB-DHM can simulate a reasonable hydrograph and spatial soil moisture distribution with calibration of only a few parameters for discharge. The model was then validated using SGP99 datasets and observed discharge. For the validation period, the model shows good performance in reproducing the soil surface temperature at 11 sites and the spatial distribution of surface soil moisture, as well as long-term discharges in a period that covers both the annual largest flood peak of 1999 and the SGP99 period. To our knowledge, this work is the first to undertake the development and evaluation of a distributed biosphere hydrological model using such comprehensive field observations.