DEVELOPMENT OF FLOOD INUNDATION-GROUNDWATER COUPLED MODEL FOR CHAO PHRAYA RIVER BASIN

Abstract

In the Chao Phraya River basin, long-term flood inundation frequently occurs, which results in severe damage of rice crops farming and has an effect on groundwater flow system. Flood inundation and groundwater problems, however, have not been examined comprehensively. In the present study, a flood inundation-groundwater coupled model is developed to examine the long-term flood inundation-induced groundwater system. The model consists of two flow models, that is, a depth-averaged flood inundation flow model and a three-dimensional groundwater model, MODFLOW-2000. The validity of the coupled model was confirmed by comparing the numerical results with the theoretical ones for the falling head permeability test. Moreover, application of the model to northern area of Bangkok in Thailand showed the infiltration of inundation water into aquifers affected the groundwater system.