圖書典藏及影音數位平台

透過本研究將農業區之蓄洪減洪效果與常用區域排水分析模式相結合，佐以實測降雨-排水水位等水文資料的檢驗，檢討區排分析模式參數在農業區蓄洪減洪之合理性及適用範圍等及對排水計畫洪水量影響，提供排水規劃之參考。

The purpose of this project is to carry on the drainage simulation for agricultural areas using diffusive tank model in order to analyze the effect of flood detention and the influence of that on design discharge of regional drainage system. The project selected two regional drainage systems such as Luliao main drain system and Yonsian middle drain system as experimental areas. Approximately 70% of the land use within the experimental areas is agricultural areas engaged in agricultural operations. In Luliao main drain experimental area, about 90% of agricultural area in first season crop is paddy field, but about 80% of agricultural area in second season crop is turned to upland field. In Yonsian middle drain experimental area, agricultural area is upland field in the whole year. Inundation analysis in this project is using diffusive tank model as a tool to execute the numerical simulation based on rainfall-runoff characteristics for agricultural areas. The analysis results will be compared to the analysis result obtained from SOBEK model to further explore the applicability of inundation analysis of low-lying agricultural areas by diffusive tank model. In addition, according to the drainage characteristics of the different land use, estimate the flood detention effect of the agricultural area preliminarily. This year is the first year of the two-year plan, the major items include the selection of experimental areas, the investigation and collection of hydrological data and physiographic basic information, the build of diffusive tank model and the flood simulation of experimental areas. Using the collected rainfall events, preliminary simulations by diffusive tank model and SOBEK model are run to find out more suitable model parameters for the two experimental areas. The analysis results show that in the Manning value estimated by current situation, two models are both presented good simulation results, while the change of Kn value based on land use is not high sensitivity for the analysis results of SOBEK model. Taking Luliao main drain experimental area as an object, three rainfall events such as 20120614, 20120722 and 20120725 were used to analyze the flow difference from paddy and upland field, the results show that compared with upland field status, in paddy field status the reduction percentage of flood peak is 81.61%, 81.02%, 75.17%, respectively; the detention amount per unit area is 155.15、55.35、60.12 ( ), respectively and the detention time of peak discharge is about 70 minutes.