Abstract: This paper describes a study carried out to estimate runoff for different rainfall events in 8 sub basin of Hiran river (Gujarat). This research emphasizes the western part of Gujarat for runoff prediction techniques. The Hiran River originates from the Gir forest, moves towards the river mouth, and meets the Arabian Sea near Somnath. The two hydrological models, HEC-HMS and IHACRES, have been simulated for runoff generation in this research. In addition, input parameters like rainfall, temperature, curve number, and DEM are utilized for modeling purposes. The discharges of both models are compared with the observed data acquired from the state water data center. In this regard, various statistics are calculated, like the coefficient of determination (R2).This research enlightens the hydrological modeling for the ungauged river basins. The results help the global community decide to establish the new hydraulic structure, crop pattern, and hydrological monitoring.

Keywords: HEC-HMS, IHACRES, Rainfall-Runoff model, Co-efficient of determination.

| DOI: 10.17148/IARJSET.2024.11446