Flood Inundation Simulations based on GSMaP Satellite Rainfall Data in Jakarta, Indonesia

Abstract Jakarta is the capital of Indonesia and is considered as one of the most vulnerable cities to climate-related disasters, including flooding, sea-level rise, and storm surge, in the world. Therefore, the development of a flood-forecasting system for Jakarta is crucial. However, the accurate prediction of flooding in Jakarta is challenging because of the rapid flood-concentration time in highly urbanized basins and the shortage of rainfall data in poorly gauged areas. The aim of this study is to simulate flood inundation that occurred in recent years using global satellite mapping of precipitation (GSMaP) products. The GSMaP products (NRT and Gauge V7) were evaluated and compared with the observation data obtained hourly from five ground stations in the Ciliwung River Basin. In addition, a rainfall-runoff and flood inundation model were applied to the target basin. The results of the analysis showed that the GSMaP Gauge data were more accurate than the GSMaP NRT data. However, the GSMaP Gauge could not be used to provide real-time rainfall data and is, therefore, inadequate for real-time flood forecasting. We conclude that the GSMaP Gauge is suitable for replicating past flood events, but it is challenging to use the GSMaP NRT for real-time flood forecasting in Jakarta.