[A-HW19] Hydrology & Water Environment

[AHW19-16] Detailed Flood Inundation Modeling for Paddy Field Dams

*Shuangtao WANG¹, Takahiro Sayama² (1.Chang An University, 2.Kyoto University)

In recent years, large-scale floods have occurred frequently due to the increasing occurrence of concentrated rainstorms, the economic losses and human losses caused by floods are expected to increase in the future. The paddy fields themselves are believed to have an innate flood control function. Paddy dams stabilize and control the amount of water falling by installing drainage holes in paddy fields, smoothing peak runoff during storms and mitigating downstream flooding. In order to quantify the effect of paddy field dams on flood reduction, we developed a detailed paddy flood simulation model. Then, the effects of paddy field dams on paddy discharge and inundation were simulated under different rainfall return periods. The results show that paddy field dams can effectively slow down the drainage process, reduce the drainage discharge, and increase the water storage of paddy fields. Paddy field dams can reduce peak discharge by nearly 70% in the case of a 50-year return period design rainfall event, increase paddy field water storage capacity by more than 30%. These results confirmed that the paddy field dam project is functioning effectively, as far as the study area is concerned.