| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 100 === This study used the BASINS/HSPF model to simulate the flow and water quality in the Feisui reservoir watershed. By dividity the watershed into three subwatershedbased on geographical features: Pei-shi, Dai-yu-ku, Jin-gua-liao creek watersheds, data of current five years (2006 to 2010) of hydrology and water quality were used to calibrate and validate the model. This study focused on the suspended solids (SS) and total phosphorous (TP) as the target pollutants. From the matching of actual data, the pollutant loads of suspended solids (SS) and total phosphorous (TP) could be estimated by the model. In addition, the development of TMDL (tatal maximum daily load) was based on the existing environmental standard for protection of water body for each watershed. From TMDL and simulation of pollutant loads of TP, the required TP removal rate for each watershed was derived. Four types of potential BMPs (best management practices) were employed to the areas where TP concentrations were high. There BMPs in the model are wet pond, conctructed wetland, grass swale, and filter strips.
The calibration model showed that Pei-shi creek watershed’s SS pollutant loads was 6,961 ton/yr, and TP pollutant loads was 18,575 kg/yr. Dai-yu-ku creek watershed was 64,214 ton/yr of SS, and 7,597 kg/yr of TP. Jin-gua-liao creek watershed was 1,033 ton/yr of SS, and 2,581 kg/yr of TP. Consequently, the Pei-shi creek watershed had the most SS and TP pollutant loads in the watershed. The estimation of TMDL, it was assumed that 5% MOS value and 1% future growth. Compared the simulated pollutant loads with WLA+LA (waste load allocation+ load allocation), Pei-shi and Jin-gua-liao creek watersheds need to employ the BMPs.
Base on the result of BMPs simulation, the constructed wetland and grass swale have a better removal rate for TP. While the removal rate by filter strips was lowest.However, there BMPs couldn’t reduce the pollutant loads to below the TMDL.
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