Ciujung river basin flood risk assessment due to climate change and its countermeasure

• Published in: IOP conference series. Earth and environmental science Vol. 1343; no. 1; pp. 12037 - 12047
• Main Authors: Putriasri, A E, Eliasta, L, Amatullah, S I, Sandi, C, Pahlevi, A R, Hikmat, S N, Jaya, I, Kosasih, B, Rahmawati, A, Hermawan, Y
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.05.2024
• Subjects: Climate change; Discharge; Discharge hydrographs; Effectiveness; Environmental risk; Flood discharge; Flood peak; Flooding; Floods; Hydrographs; Hydrology; Land use; Risk analysis; Risk assessment; River basins; Rivers; Two dimensional models
• DOI: 10.1088/1755-1315/1343/1/012037
• ISSN: 1755-1307

Abstract Ciujung River is experiencing recurrent flooding, which was caused by climate change factor and extensive land use change. Therefore, this study carried out risk assessment in this basin area. First, hydrology analysis was carried out using HEC-HMS software to obtain flood discharge hydrograph, with obtained peak discharge of 3534.3 m 3 /s for 25-year return period. This hydrograph was then modeled into an inundation map using HEC-RAS two-dimensional model to calculate hazard index. Meanwhile, the vulnerability and capacity index were calculate using the demographic data. Finally, the risk index was calculated by combining hazard, vulnerability, and capacity index using raster calculator on Arc-GIS. Overall, the flood risk analysis shows a medium level. The results shown that hazard index is the most contributing factor in causing a high risk index. Thus, in this study we proposed a structural approach to reduce the hazard index. An embankment with a length of 50.37 km was applied and remodeled to analyze its effectiveness. The modeling results show high effectiveness with a significant reduction in inundation area. The reduction of inundated area reached 39.6%, while the reduction of affected buildings reached 49.9%. Hopefully, the result of this study can provide theoretical support and recommendations for future development.