Evaluasi Potensi Bahaya Banjir di DKI Jakarta Menggunakan Analisis Multi-Kriteria dan Satelit Berbasis Flood Hazard Index (FHI)

Abstract

Floods are one of the most destructive and common natural disasters in the world. Globally, flood disasters have an increasing trend from year to year. In Indonesia istelf, the number of flood disasters from 2011 to 2020 was recorded at 7.574 cases which caused losses in several aspects of life. Losses caused by flooding include death, minor/severe injuries, missing persons, damage to houses, access roads, as well as education and health centers. Various methods have been applied as a preventive action for flood control. One of the methods commonly used to prevent flooding is creating water infiltration channels and cleaning rivers periodically from garbage. However, there is another approach that can be used, namely by making a flood hazard map based on the Flood Hazard Index (FHI). The FHI method is able to combine Geographic Information System (GIS) analysis with Multi Criteria Decision Analysis (MCDA) to obtain flood hazard maps. The MCDA technique used is Analytical Hierarchy Process (AHP) to determine the weight of the influence of factors on flood events. This study aims to obtain the level of flood hazard in DKI Jakarta and the most influential factors in causing flooding. In the analysis process, the seven factors that cause flooding in DKI Jakarta are defined, namely flow accumulation, distance from rivers, density of river networks, slopes, rainfall intensity, land cover, and geology. AHP analysis is used to obtain weighted scores, while GIS analysis is used to obtain scores. The value of weights and scores are combined to obtain FHI. Sensitivity analysis was then carried out to obtain the effective weights used in constructing the flood hazard index. The FHI map, FHI sensitivity (FHIS), and FHI equal weight (FHIW) were validated using the 2013 flood inundation map to find the index that best represents flood events in DKI Jakarta. The results of the analysis show that the FHIS index is best used to represent the flood hazard in DKI Jakarta (59%). Factors that influence in causing flooding are rainfall intensity, followed by land use, and slope. FHIS values have a pattern of high in the north and low in the south. This indicates that the northern region has a higher level of danger than the southern region. This phenomenon occurs due to the high intensity of rain in the northern part of Jakarta due to its location close to the Java Sea. In addition, the northern area of Jakarta is downstream of 13 rivers so it has a higher potential for flooding.