Analysis of Flood-Vulnerable Areas Using Scoring and Weighting Methods Based on Geographic Information Systems (Case Study: Sidoarjo Regency)

Abstract

Indonesia is a country that is very vulnerable to natural disasters, one of which is flooding. A flood is an event or situation in which an area or land is submerged due to increased water volume. According to the National Disaster Management Agency (BNPB) records, throughout 2021, the most frequent disasters were floods, totaling 1,298 incidents. Floods also occurred in Sidoarjo Regency, specifically on Sunday, 17 January 2021, from afternoon to evening, with high rainfall intensity submerging two sub-districts. The highest flood in Tanggulangin District was in Kedungbanteng Village. As a result, as many as ± 408 Heads of Families (KK) were affected. Furthermore, in Porong District, the highest flood was in Pesawahan Village. As many as ± 490 Heads of Families (KK) were affected. Therefore, further analysis is required regarding the causes of the flood. In this research, an analysis was carried out regarding flood-prone areas in Sidoarjo Regency using a scoring and weighting method based on geographic information systems. This research used six parameters comprising land elevation, slope, rainfall, soil type, river flow density and land cover, which were then given scores and weights for each parameter based on the size of the parameter. After scoring each parameter, a weighted overlay is performed to obtain a flood-vulnerable map. The results of the flood vulnerability level in Sidoarjo Regency are divided into three vulnerability classes, namely low class with an area of 1100.84 Ha (1.71%), medium class with an area of 58143.33 Ha (90.52%), and high class with an area of 4987. 06 Ha (7.76%) of the total area of Sidoarjo Regency.