VISUALIZATION OF SPILLOVER FACTORS OF PADDY FIELD DAM

Abstract

 Paddy Field DAM is designed not to spillover if levee hight is maintained at standard level and runoff via drainage orifice is free flow. However, the results of our numerical simulations at the watershed scale presented a number of paddy fields were spilled over. This was due to several external factors, such as rainwater inflow from adjacent land parcels and backflow into the paddy fields caused by rising water levels in the drainage channels, but it was difficult to identify the factors for each of the many paddy fields in the watershed. In this study, we developed a new analytical method to visualize the inflow from the adjacent land and the backflow from the drainage canal by using the runoff component visualization model to identify the causes of overflowing rice paddies. In addition, it was demonstrated that raising the height of the levees of rice paddies was effective in reducing the occurrence of spillover.