Flood inundation hazard mapping and vulnerability analysis in the downstream area of the Cipunagara River Basin of Indonesia using Google Earth Engine

Tidal flooding is a natural phenomenon where seawater enters land areas with high sea levels. Tidal flooding is caused by factors, namely forest area decline, land degradation, hydrological conditions disturbances, household waste, improper drainage, and rising tides. The North Coast of Java that has the potential to be affected by tidal flooding is the downstream area of the Cipunagara River Basin, Subang Regency. Factors causing disasters include runoff from the Cipunagara river, sea water intrusion, changes in coastal land use, sea level rise, and the presence of river water overflows every year, which play a role in the expansion of the tidal area of flood inundation. The purpose of this study is to map the risk of tidal flooding based on the hazard index, vulnerability index. The determination of the risk index is carried out using a spatial method to identify the hazard index and vulnerability index, by scoring or overlaying through the GEE and ArcGIS 10.8 applications, as well as qualitative descriptive methods in determining disaster capacity. The high-vulnerability category for tidal flooding is found in the villages of Legon Kulon, Patimban, Pusakaratu, Mundusari, Rancasari, Pamanukan Sebrang, Mulyasari, Pamanukan Hilir, Pamanukan, Lengkong Jaya, and Pusakajaya with a tidal flood vulnerability index scoring range, which is 3.2 – 3.8. The moderate vulnerability category was found in the villages of Bobos, Karangmulya, Rancadaka, and Gempol with a scoring range of 2.6 – 3.2. While the category of low tidal flood vulnerability index was in Tegalurung, Mayangan, Legon Wetan, Pengarengan, and Ranca Hilir with a tidal flood vulnerability index score range of 2.0 – 2.6. This vulnerability index will be expanded to determine the Capacity index and Risk index for the same location of study.