Physically-based, distributed hydrologic model for Makkah watershed using GPM satellite rainfall and ground rainfall stations

The purpose of this study is to understand flooding in a 1,725-km2 arid catchment Makkah Province, Saudi Arabia, with very limited ground observations. This mountainous includes densely urbanized areas built on lowlands and the ephemeral streams flood zones, which makes them vulnerable flooding. A physically based, fully distributed hydrologic model was produced by three Integrated Multi-satellite Retrievals for Global Precipitation Measurement Mission (IMERG) high-resolution satellite rainfall products, together number observations simulate recent events. calibrated validated using two events that occurred 2010 2018, respectively. Details were examined through simulation third event. Significant differences noticed when IMERG products (Early, Late, Final) compared terms spatial patterns total half-hour accumulation Accordingly, method developed remove biases estimates Early product closest observations, producing peak discharges 428 m3/s 663.6 calibration validation storm events, respectively, resulted better observed discharge even before adjustment. Final run significantly underestimated rainfall, as 204 123 an amplified underestimation runoff.