Jakarta Flood Risk Mapping Using Index-based Approach and Spatial Analysis

Flooding occurs almost every year in Jakarta during the rainy season, including earlier this year in 2020. This is considered alarming because the scale of the flooding impact has increased rapidly in recent decades. The increase was related to a number of drivers, both physical (climate change) and socio-economic (population growth). This proposed a new approach based on the impact of both factors on flood risk, considering flood hazard and vulnerability in quantifying risk using an index-based approach. Spatial analysis is utilized to create thematic maps used to identify the geographical variation of flood risk among subdistricts. The result indicates that 16 percent of Jakarta subdistricts, mainly concentrating around Central, West, and North Jakarta, have a high risk of flooding.

I. Introduction

Jakarta is the capital of Indonesia, which is affected by flooding almost every year. Even though flooding in Jakarta is not considered new, the scale of flooding impact has increased rapidly in recent decades [1]. This increase was related to a number of driving factors, both from the socio-economic and physical aspects. The main driving factor of the socio-economic aspect is population growth [2]. The higher the number of population living in a disaster-prone area, the higher the scale of risk that can occur. One of the most significant physical driving factors is climate change. Evidence of the climate change effects recently encountered is the highest rainfall ever recorded in Jakarta, resulting in the Jabodetabek flood earlier this year. The incident claimed 67 lives, including 16 Jakarta residents. Causes of death vary from hypothermia to being swept away by flood currents. The rainfall recorded on that day was the highest since the first measurement in 1866, which is 377 millimeters (mm) per day at Badan Meteorologi, Klimatologi, dan Geofisika (BMKG) Station of Halim Perdana Kusuma. The previous highest rainfall record was held by the 2007 flood, which was 340 mm/day.