| Summary: | 碩士 === 國立成功大學 === 水利及海洋工程學系碩博士班 === 91 === Urbanization is significantly increasing in Taiwan recently because of economic development. The basin Yan-Shoei creek is chosen as the study area to investigate the influence of urbanizing on runoff hydrograph and flood storage ability, which are the subject we concern. To mitigate the influence of land use change, the non-structure flood mitigation method is proposed. 1972 LANDSAT MSS and 2000 SPOT satellite imageries are applied to identify the land use types by using unsupervised, supervised classification methods and the method that the image was classified by supervised classification after the thematic maps were first cut off. We found the last method has the best result. The building area increases about 1600 acres from 1972 to 2000. Because the terrain of study area contains flat area and mountains, so we tried to connect the tank model for flat area with the grid-based distributed rainfall-runoff model, which is based on kinematic wave approach and has reasonable simulation in the mountains before. Calibration from 12 storm events concluded that the model proposed in this work can well simulate the rainfall-runoff relationship. The model is further applied to investigate the impact of land use change on runoff. 10-year flood was found to be increased around 10%. The paddy field at the downstream of the studied area is proposed as the flood mitigation area and the appropriate mitigation area is suggested in this work finally.
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