DETERMINATION OF FLOOD VULNERABILITY LEVEL BASED ON MORFOMETRY AND MEANDER STABILITY ON THE CIHONJE RIVER BORDER IN SUMEDANG REGENCY, WEST JAVA

• Main Author: Kartiwi, Tiwi
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65548
• Institution: Institut Teknologi Bandung

Sumedang Regency, especially South Sumedang, is classified as an area prone to landslides and flash floods. In March 2021, there was a flash flood that hit the village of Citengah to the village of Baginda, South Sumedang District. Based on information obtained from BPBD Kab. Sumedang, the incident occurred during heavy rains, causing an increase in water discharge in the Cihonje River. In addition to high rainfall, river morphometry and meander stability are strongly suspected to be the triggering factors for this flash flood. Based on this, it is necessary to research the level of flash flood vulnerability based on the two physical factors of the river above. This research was conducted in the Cihonje River area which is included in the Cipeles sub-watershed, Cimanuk watershed which flows along with Citengah Village, Cipancar, Gunasari, and Baginda. The location of the research was carried out on a river border of 140.37 ha which is divided into three parts, namely the upstream, middle, and downstream parts. This study aims to determine the level of flash flood vulnerability, river flow discharge, and meander stability along with the Cihonje River flow. The level of flash flood vulnerability is determined spatially to produce a map of the level of flash flood vulnerability, while the flow rate of the river is measured by the buoy method, followed by the calculation of the river meander stability using the meander stability method. The results showed that the level of vulnerability to flash floods in the Cihonje River border can be categorized into three, namely the slightly vulnerable level of 19.16 ha (13.69%), moderately vulnerable to an area of 43.17 ha (30.84%), and prone to flooding covering an area of 77.64 ha (55.47%). Another result is that the downstream the river flow is increasing, which indicates that the Cihonje River as a whole is classified as prone to flash floods. The results of the meander stability calculation show that the Cihonje River is classified as unstable (rc < 40A0.5). This study concludes that most of the Cihonje River border has a high level of flash flood vulnerability because it is influenced by land use, river flow discharge, and unstable meanders.