應用二維數值模式於坡地農塘清淤滯洪成效之探討

過去水土保持保育治理成效探討，多著重於水土保持結構物之防砂功能及效益，有關坡地治理對下游淹水減降助益常無法提出具體數據及案例，且較少著墨於整體治理後滯洪能力提升之探討，然流域綜合治理計畫係以逕流管理，出流管制為目標，本研究藉由臺南市山上區蚵潭橋野溪農塘、新化區農改場農塘及高雄市內門區望寮農塘等3處農塘清淤工址，探討坡地滯洪能力提升成效，採用FLO-2D數值模式模擬滯洪設施設置前後流量歷線變化、洪峰延遲時間或洪峰削減量體，提供易淹水地區上游坡地滯洪對策研擬參考，作為後續水土保持保育治理工作推動之依循。

關鍵字

數值模擬；農塘清淤；滯洪效益

並列摘要

Effectiveness of soil and water conservation has been focused on sediment control; whereas the flood and runoff retention has not received equal attention so that quantitative assessment has seldom been able to reach and provide recommendation for slopeland management. Therefore, this study applies FLO-2D to assess the effectiveness of runoff retention at Tainan Agricultural Research Extension Station, Xinhua District, and Wangliao, Neiwan District, Kaohsiung City. Results of numerical simulation include the changes of runoff hydrographs, lags of peak flow arrival time, and reductions of peak runoff rates prior and after degrading operations of farm ponds. The simulation results provide recommendations for future slopeland management particularly for the purposes of runoff reduction and flood mitigation.