干旱区生态环境知识资源中心

Despite being interconnected and a single resource, groundwater and surface water are sometimes perceived and managed as two separate entities. Increased human demand and uncertainties associated with global climate change have made more urgent and necessary to manage as a single resource. This study investigates hydrologic response of a medium sized watershed (similar to 5,000 sq. km) in arid/semi-arid region of the western United States, using a fully integrated surface-subsurface hydrologic model. A fully-integrated, physically-based, distributed numerical model that accounts for three-dimensional variably-saturated subsurface flow and two-dimensional overland/stream flow, HydroGeoSphere was used to simulate the multi-year hydrologic response of the Lower Virgin River Basin (LVRB) in the southwestern United States. Watershed response on the evolution of surface and subsurface flow systems such as recharge-discharge area, loosing and gaining reaches, spatial and temporal distribution of evapotranspiration, and watershed effect on surface runoff were examined over a period of successive years. Despite computing time limitations to performing finer calibrations, simulations were effective in identifying losing and gaining sections of recharge and discharge areas, runoff generation, and spatial and temporal distributions of actual ET.