Spatial analysis of flood-prone areas and flood discharge

Abstract

The Wanggu watershed is a natural ecosystem that is very sensitive to changes in land use. Increased changes in land use and geomorphological conditions in the Wanggu watershed such as slope levels, altitude, soil texture, natural drainage density, rainfall factors and the influence of infrastructure development (road construction, housing) will affect the hydrological response of the watershed and become the cause of increased flood vulnerability in the region. The purpose of this study is to analyze the factors causing flood vulnerability and its impact on the city of Kendari and the Wanggu watershed and to determine the level and distribution of flood vulnerability in the Wanggu watershed area by utilizing geographic information system technology (GIS). This study uses Scoring, weighting, and Overlay methods on several parameters causing floodings such as rainfall, land use, slope, soil texture and height, drainage density, and infrastructure. The results showed that the causes of flooding in Wanggu watershed are rainfall, land-use change does not match the ability class because it is dominated by 40.1% flat slope, medium to rough soil texture 82.3%, altitude 29.0%, moderate drainage density 89.3% and run-off discharge 82.53 m3s-1. The Wanggu watershed has four flood vulnerability classes, namely safe 27.7%, rather vulnerable 16.0%, vulnerable class 32.6%, and very vulnerable class 23.6%. The flood hazard class that dominates the Wanggu River Basin area is the Prone Class.