Analysis Of Sedimentation Influence On The Lifespan OF The Semantok Dam Nganjuk Based On Arcgis

Semantok Dam is a dam located in Kedungpingit Hamlet, Sambikerep Village, Rejoso District, Nganjuk Regency, East Java. The Semantok Dam was built on the Semantok River which is approximately 18.19 kilometers long with a watershed area covering a water catchment area of approximately 54,032 square kilometers. The high level of erosion at the Semantok watershed outlet will increase the amount of sediment entering the Semantok Dam and will affect the dam's lifespan. Sedimentation analysis at the Semantok Dam is used to calculate the level of erosion and the rate of sedimentation that occurs, which can be used to determine the remaining lifespan of the dam. The method used in this research is the USLE (Universal Soil Loss Equation) method with the help of ArcGIS software. From the research results, it was found that the rate of erosion that occurred in the Semantok Watershed is 954.31 tons/hec/year, the rate of sedimentation entering the Semantok Dam is 88642,6212 m3/year, and the remaining lifespan of the Semantok Dam is 47-48 years.