Skripsi
ANALISIS DEBIT LIMPASAN AKIBAT PENGARUH PERUBAHAN TATA GUNA LAHAN (STUDI KASUS TAHUN 2012 & 2022 DAS JUARO DAN DAS SELINCAH)
The Musi watershed, part of the Musi River, covers an area of ±77,602 km2 with the main river 750 km long. Palembang is divided into 21 Sub-Watersheds. Land change from forests/rice fields to settlements/industries reduces water absorption, increases runoff, and causes flooding. The Juaro and Selincah watersheds in Kalidoni, including flood-prone areas, are caused by increasing urbanization, poor drainage, high rainfall, and lack of green open space. Therefore, the purpose of this study is to analyze flood discharge in the Juaro watershed and Selincah watershed by comparing the Rational, HSS SCS, and Nakayasu HSS methods. The analysis shows that flood discharge in the Juaro and Selincah watersheds from 2012 to 2022 has increased based on rational methods and the SCS HSS. In the Juaro watershed, the increase in flood discharge from the repeat period of 2, 5, 10, 25, 50, 100 consecutive years is 2,3185%; 2,215%; 2,169%; 2,127%; 2,097%; 2,074% for rational methods, and 4,530%; 3,854%; 3,556%; 3,284%; 3,091%; 3,060% for the HSS SCS method. For the Nakayasu HSS method, there was a decrease of 0,585%; 0,688%; 0,734%; 0,776%; 0,806%; 0,829%. In the Selincah watershed, the increase in flood discharge was 0,303%; 0,2%; 0,154%; 0,112%; 0,082%; 0,059% for rational methods, and 1,012%; 0,739%; 0,623%; 0,519%; 0,446%; 0,391% for the HSS SCS method. For the Nakayasu HSS method, there was a decrease of 0,585%; 0,688%; 0,734%; 0,776%; 0,806%; 0,829%. This increase is due to lower C and CN values in 2012 compared to 2022, so the potential for flood discharge increases. On the other hand, the Nakayasu HSS method shows a decrease in flood discharge due to rainfall intensity data that decreased from 2012-2022.