Identifikasi Sub DAS Rawan Banjir dengan Metode Cendana (Studi Kasus: DAS Aesesa pada Wilayah Sungai Flores)

Abstract

The Aesesa watershed is the largest watershed in the Flores River Basin located in Ngada Regency and Nagekeo Regency, with a watershed area of 1,169.24 km² and a main river length of 66.92 km. The Aesesa watershed consists of 13 sub-watersheds with varying shapes and complex characteristics. This makes the Aesesa watershed potentially prone to flooding. The purpose of this study is to identify the potential for flooding from sub-watersheds in the Aesesa watershed using the Cendana method. The data used include morphometry data, watersheds, and maps. In using the Cendana method, the input parameters taken into account are watershed area (A), main river length (L), annual maximum daily rainfall, watershed shape, river density (D), river slope (s), Nakayasu α value, channel roughness (n), curve number value (CN), and land cover. Then from the calculation of the data, value weighting will be carried out to identify flood vulnerability. The results of this study show that the weighting for 13 sub-watersheds in the Aesesa watershed is on average in the high category with a range value of 2.30 – 2.70. From this result, it is expected that mitigation and adjustment efforts can be made, especially in sub-watersheds that are already high with a weight value of 2.70 to reduce the magnitude of losses due to flooding.