Watershed Flood Vulnerability Assessment Based Land Subsidence Analysed from a Long Time Period of Sentinel-1 Radar Data

Abstract

Identifying flood vulnerability in an area is part of disaster risk management, especially for mitigating flood events. The level of vulnerability can be recognized from many factors. One of the primary sources of flood vulnerability in urban lowland areas is land subsidence. Sentinel Radar data has been proven to be able to produce land subsidence data accurately. This study was conducted using two Sentinel 1A Radar data acquired on 7 December 2014 and 20 August 2021. Determining the level of flood vulnerability, the analysis of land subsidence is operated at the watershed scale. The highest land subsidence recorded in the Kali Sunter watershed area was 81mm in Kayuputih Village, East Jakarta City. The villages classified as “Extremely Vulnerable” are Sumurbatu in Central Jakarta City, Kayuputih in East Jakarta City in Kelapagading Barat in North Jakarta City and Mekarsari in Depok City.

Application of Spatial Model the Contribution of Land Subsidence Caused by Palm Oil Plantations Land Clearing to the Escalating Flood Risk in the Trumon Area, South Aceh Regency, Indonesia

“…Land subsidence can caused basins to trap water flow. Water from upstream cannot be adequately streamed through existing waterways but will cause inundations that can potentially become floods [30]. In low-lying landscapes, subsidence enhances the risk of flooding since under certain conditions land subsidence able to expand the rainwater catchment area of a watershed (DAS) located in the lowlands, therefore the volume of water discharge increases [31].…”