Hydrological Analysis of Al-Rafee Watershed for Sustainable Rainwater Harvesting

This study aimed to conduct a hydrological analysis and assess the potential for rainwater harvesting using GIS-AL technologies for the Al-Rafee’ watershed, located in the eastern part of Iraq within the governorates of Salah Al-Din and Diyala Provinces. The total area of the basin is 212.19 km², lying between latitudes (34°33’18"–34°33,49"N) and longitudes (44°35’22"–44°46’17"E). The study relied on the SCS-CV model to estimate surface water runoff volume. The findings indicated the presence of three hydrological soil groups: B, C, and D. The land cover was found to be diverse, with agricultural lands occupying the largest area (91.12 km²), while barren lands had the smallest coverage (0.22 km²). The study also showed high Curve Number (CN) values and low retention (S) values. Furthermore, it concluded that it is possible to establish reservoirs to collect rainwater at the identified locations, with the aim of developing the studied region for future investment opportunities.