Analisa Perbandingan Metode Analisis Debit Banjir di Sungai Deli Kecamatan Medan Maimun

Abstract

Flood is a river condition where the water flow is not accommodated by the riverbed. In the rainy season, high rainfall results in greater river water discharge. Because the large river water discharge is not able to create a river channel, then the river floods and if it exceeds the river bank, there will be flood or including damage to the embankment. The Deli River is one of the main river in the Belawan/Belumai Ular River Basin Unit (SWS) with 5 (five) tributaries. The length of the river is about 73 km with a basin area of 402 km2. The Deli River is the largest contributor to air resources for the residents of the city of Medan. Synthetic Unit Hydrograph (SUH) is a unit hydrograph derived based on river data in the same watershed or different watersheds but have the same characteristics. Synthetic unit hydrograph can be used if the available rainfall and discharge data are insufficient so that the reduction of the watershed hydrograph units can be done synthetically. This study aims to determine the amount of flood discharge on the Deli River in Medan Maimun District using the HSS Gamma I, HSS Nakayasu, Weduwen and Melchior methods and to analyze the accuracy of the four methods with AWLR datas. The methodology used in this study is the HSS Nakayasu, HSS Gamma I, HSS Melchior and HSS Weduwen methods. Based on the analysis, it can be seen that the four methods provide quite far from the frequency analysis method as a measure of desire. The HSS Melchior, HSS Gamma I, and HSS Weduwen methods obtained results that were too large and tended to be overestimated. Thus the results obtained are the Nakayasu HSS method which has the smallest difference when compared to the flood discharge data at the research location.