Comparative Application of Rain Gauge, Ground- and Space-Borne Radar Precipitation Products for Flood Simulations in a Dam Watershed in South Korea

This study presents a comparative analysis of flood simulations using rain gauge, ground- and space-borne radar precipitation products. The objectives are to assess the effectiveness two radar-based data sources, namely Radar-AWS Rainrates (RAR) Integrated Multi-satellite Retrievals for GPM (IMERG), in dam watershed with gauge observations, explore modeling feasibility integrating half-hourly IMERG satellite regions ungauged or limited observational area. Two types HEC-HMS models were developed, considering areal-averaged spatially distributed gridded utilizing eight selected storm events. findings indicate that RAR data, although slightly underestimate compared measurements, accurately reproduce hydrographs without requiring parameter adjustments (Nash–Sutcliffe efficiency, ENS, 0.863; coefficient determination, R2, 0.873; percent bias, PBIAS, 7.49%). On other hand, exhibit lower model efficiency correlation, suggesting potential limitations watersheds. Nevertheless, available discharge calibrated shows prospects utilization (ENS 0.776, R2 0.787, PBIAS 7.15%). Overall, this research offers insights into various products, emphasizing significance reliable accurate hydrological need further evaluation product.