Development of a Grid-based Distributed Runoff Model and Flood Scenario Analyses in Dau Tieng River Watershed, Vietnam

Abstract

  In this study, we propose a grid-based distributed runoff model based on the spatial distribution of rainfall and land use in Dau Tieng River watershed, Southern Vietnam. In the model, the inflow/outflow matrix was integrated to effectively represent water flow between meshes, simplify programming, and shorten calculation time. Model accuracy was almost satisfactory even though rainfall and discharge observations were limited. The model was then applied to predict future changes in runoff resulting from a number of rural development and global warming scenarios. Results of the scenario analyses showed that land use changes due to rural development led to increased runoff and a more peaked hydrograph, and that variations in runoff were proportional to the rainfall variability rate associated with changes in rainfall due to global warming.