Coupled surface and ground water models for investigating hydrological processes

This study examines a physical based distributed-parameter model combining surface runoff and ground water flow. Surface runoff is composed of both overland flow and river flow components, and the ground water module considers the unsaturated zone and saturated zone in an unconfined aquifer system. Previous works of surface flow module development was presented, the ground water module development and complete hydrologic processes simulations are conducted in this paper. Proposed watershed model is designed to deal with physics-based multiple processes occurring in watershed, including evaporation, infiltration, percolation, surface runoff and ground water flow. This study used a proposed watershed model for the simulations of extreme flood events and long-term periods that occurred in the Shihmen reservoir watershed from 1996 to 2001. This hydrological model is a flash reacting watershed model, showing good potential for storm based simulations, recession period description and long-term modelling. Therefore, the proposed model is confirmed to be suitable for Shihmen reservoir watershed simulations.