Groundwater Table Simulation Under Different Rice Irrigation Practices

Abstract

Most rice culture in southern Asia occurs on relatively flat soils with seasonally high groundwater tables. Groundwater is often available for use during the dry season for irrigation. Bangladesh is a southern Asian country where dry season rice (or boro) irrigation is rapidly increasing, causing concern for possible groundwater depletion. This paper describes a simulation model developed to analyze the impacts that different irrigation management schemes have on groundwater levels. The model includes all aspects of the hydrological cycle, such as precipitation, irrigation, evapotranspiration, percolation, recharge, and river base flow. It consists of two linked models—one for the vadose and one for the groundwater zones. The model is checked for realism in northwest Bangladesh where four irrigation management schemes are also tested for their groundwater mining potential.