Investigation of Flooding Potential in Tongxiao Watershed by using PSD model

• Main Authors: Kai-chen Chien, 簡愷辰
• Other Authors: 詹勳全
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/13673452218397781085

碩士 === 國立中興大學 === 水土保持學系所 === 104 === The study is used Physiographic Grainage-Inundation model to simulate inundation potential in the Tonxiao River catchment due to heavy rainfall and typhoons, and then compare with the historic field measurement concerning inundation depth and area recorded as flood occurs to validate the efficiency of the model. Collecting and treating the hourly rainfall data form Water Resoureces Agency, Ministry of Economic Affairs and Central Weather Bureau, used the eleven durations (1-hour, 2-hours, 3-hours, 4-hours, 6-hours, 8-hours, 10-hours, 12-hours, 18-hours, 24-hours and 48 hours), then chose the maximum volume of rainfall to do return periods frequency analysis (2-years, 5-years, 10-years, 25-years, 50-years, 100-years, and 200-years) and calculate each rainfall intensity, and then used nonlinear regression analysis to estimate parameter of Horner formula, that applied to calculate the inundation potential under the rainfall of each return period in the Tonxiao River catchment. According the simulated results, the inundation area in Tonxiao River catchment could be sorted into three parts: (1) the upstream is in the low-altitude part of the river, where the surface runoff flows to when there is heavy rainfall; (2) the mid-upstream is near by the junction of Fuyuan Village and Pingan Village, and the Shie-Po Brige of Neihu Village, Tongsiao Township, and the inundation reason is the sediment deposited in the river, that causes the cross section is not enough; (3) the downstream is near by the Tong-Siao elementary school and Pingyuan Village, Tongsiao Township, and that is because the river cross section is not enough. Lastly, comparing the simulated results and the field investigation provides the reference of improvement strategies of the inundation disaster in the Tonxiao River catchment.