民國98年莫拉克風災後，荖濃溪地區為南部重要土砂災害區域，水土保持局臺南分局於此地區投入多次野溪清疏工程，為達防災目的，本研究利用無人載具航拍高屏溪流域上游荖濃溪拉庫斯溪匯流口並測製地表數值模型(DSM)，透過多期影像進行土砂變遷判釋，並以CCHE1D一維土砂動床模式於匯流口重點災害斷面進行模擬，了解其底床變動情形，由民國109與110年災害事件模擬結果比對現場調查趨勢進行檢定與驗證，後續分析於重現期5、25及50年條件下，匯流口上下游之淤積趨勢，結果顯示當拉庫斯溪於重現期降雨事件發生時，平均淤積深度約為2-5公尺，建議定期於颱風、豪雨事件檢視本區域是否尚有足夠通洪斷面，以確保附近聚落之安全。

After the Morakot typhoon disaster in 1998, the Law-Long River watershed was an important sediment disaster area in the south of Taiwan. The Tainan Branch of the Soil and Water Conservation Bureau invested in this area for several times of dredging projects. At the confluence of the La-Cus Creek in the upper reaches of the Law-Long River, the surface numerical model (DSM) was measured and the soil and sand changes were interpreted through multi-phase images, and the CCHE1D one-dimensional soil-sand moving bed model was used to simulate the key disaster sections of the confluence. The change of the bottom bed was verified and verified by comparing the simulation results of disaster events in 2020 and 2021 with the trend of on-site investigation. The subsequent analysis of the sedimentation trend of the upstream and downstream of the confluence under the conditions of the return period of 5, 25 and 50 years, the results It is shown that when the rainfall event occurs in La-Cus Creek during the return period, the average deposition depth is about 2-5 meters. It is recommended to regularly check whether there are sufficient flood sections in the area during typhoon and torrential rain events to ensure the safety of the nearby settlements.