Study on the rainfall threshold for flood warning by SCS model

• Main Authors: Hao-Xuan Hong, 洪浩軒
• Other Authors: Wen-Jun Chen
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/73926760650754718636

碩士 === 國立嘉義大學 === 土木與水資源工程學系研究所 === 100 === Due to the impact of climate change, high economic development and relatively weaker geographic features, Taiwan has to face the risk of severe flood in every typhoon and torrential rain. Therefore, it is urgent to develop an accurate and precise flood warning system in order to avoid the serious flooding disaster. This research collected Taiwan, Chiayi physiographic and hydrological data and imported these data to ArcMap software for modeling the SCS model of the USDA Soil Conservation Service. The average CN value of 4 townships in Chiayi can be obtained by using SCS modeling ; these data can be calculated to estimate the effective precipitation value of the typhoon and torrential rain.The relation formula is able to be established by analyzing the connection of flooding area and rainfall that caused by typhoon and torrential rain. It is relatively effortless to apply this relation formula evaluating and determining the rainfall threshold. Furthermore, obtaining the results in the rainfall threshold is significantly better than the rainfall threshold by accumulated rainfall.In this paper, the rainfall threshold of 24 hours in Budai township is 168mm; on 48 hours of 247mm; the rainfall threshold of 24 hours in Dongshi township is 153mm; on 48 hours of 194mm, the rainfall threshold of 24 hours in Minsyong township is 182mm; on 48 hours of 239mm; the rainfall threshold of 24 hours in Xikou township is 153mm; on 48 hours of 184mm, provide the township as a reference for flood warning and future related research.