A New Hydrological Model (SEM-SHA): II. Mathematical Theory for Rainfall-runoff Module

SEM-SHA is a new distributed hydrological model which stands for soil erosion model for small-watershed of hilly areas. Its rainfall-runoff module can simulate hydrological processes, such as canopy storage, root uptake, evapotranspiration, etc. In this paper, mathematical theory for rain-runoff module was introduced. There are six main themes: calculation of canopy interception, snow pack and snowmelt, calculation of soil water-holding capacity, calculation of evapotranspiration, calculation of unit runoff yield, and calculation of unit and watershed conflux.