DEVELOPMENT OF GLOBAL TERRESTRIAL MODEL CONSIDERING SATURATED LATERAL FLOW

Abstract

 Saturated lateral flow on sub-grid scale is pointed out to have impact on global estimation of evapotranspiration and soil moisture. However, few global terrestrial models have represented saturated lateral flow explicitly.

 Therefore, this study adapted an upscaling method to MATSIRO model, one of the land surface models, in order to develop global terrestrial model which deals with saturated lateral flow within a grid explicitly. 50-year simulation with saturated lateral flow demonstrated less soil moisture in most areas than the simulated results by original MATSIRO, which could be attributed to soil moisture’s concentration in lower hill slope in each grid which leads to increase evaporation and runoff. In addtion, the results suggested that considering sub-grid distribution of vegetation is also important to evaluate the impact of saturated lateral flow on global hydrological estimation, since the difference of water-energy balance between a valley and a peak occurs when vegetations are concentrated at the valley.