Runoff estimation using SCS-CN and GIS techniques in the Sulaymaniyah sub-basin of the Kurdistan region of Iraq

• Published in: Environment, development and sustainability Vol. 24; no. 2; pp. 2640 - 2655
• Main Authors: Khzr, Bakhtiar Osman, Ibrahim, Gaylan Rasul Faqe, Hamid, Ariean Ali, Ail, Shwan Ahmad
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-02-2022; Springer Nature B.V
• Subjects: Catchment areas; Conservation; Earth and Environmental Science; Ecology; Economic Geology; Economic Growth; Environment; Environmental Economics; Environmental Management; Geographic information systems; Groundwater recharge; Hydrology; Land cover; Land use; Permeability; Rainfall; Runoff; Soil conservation; Surface runoff; Sustainable Development; Thematic mapping; Urban catchments; Urban runoff; Urbanization; Vegetation; Water; Water conservation; Watersheds; Kurdistan; Curve number; GIS; Soil conservation service; Runoff; Remote sensing
• ISSN: 1387-585X; 1573-2975
• DOI: 10.1007/s10668-021-01549-z

The need for conserving water rises as the resource becomes scarcer. The most essential step in order to manage this resource is to estimate watershed runoff. Runoff and rainfall are the main two sources that maintain ground water and recharge it. Hydrologists in the Kurdistan Region face the challenge of unavailability of data (most watersheds in the area are ungauged) or inaccurate data. The surface runoff of the study area was simulated via soil conservation service-curve number (SCS-CN) technique integrated into geographical information system (GIS). Surface runoff and curve number maps were made using the GIS created and processed data from land use/land cover (LU/LC), daily rainfall, hydrologic soil group and slope thematic maps. The results showed that the urbanization of the Sulaymaniyah watershed has increased the impermeability of the land by 40.9% for the period from 1999 to 2019. The runoff depth was 40.2% higher in 2019 as compared to 1999 due to the increase of the impermeable surface area. Research has also revealed a growth in built-up areas with a decrease of coverage in vegetation, resulting in a greater depth of surface runoff in urban catchment areas.