Environmental Modeling of Virtual Dams and Assessment of Their Impacts Using Geospatial Techniques in the Karza Valley Basin, Duhok Governorate

Abstract

This study aims to employ geospatial techniques in environmental modeling to identify optimal locations for virtual dams in the Karza Valley Basin, Duhok Governorate, using Landsat-8 imagery and a Digital Elevation Model (DEM) with a spatial resolution of 10 m. The Analytical Hierarchy Process (AHP) was applied to determine the weights of criteria and to construct a spatial model for classifying suitability levels. The study seeks to identify the most efficient dam sites and analyze the environmental and geomorphological constraints influencing site selection, thereby supporting water resource planning decisions and enhancing sustainable water management. The results of the spatial analysis revealed a clear variation in suitability levels within the basin, where high-suitability areas are concentrated in the central and upper parts characterized by moderate slopes and suitable geological formations, while medium suitability dominates a larger portion of the basin. Low-suitability areas are mainly associated with steep slopes and geomorphologically unstable conditions. In terms of proportional distribution, high-suitability areas represent a limited share (20–30%), medium suitability dominates (40–50%), while low suitability ranges between (20–30%). This pattern highlights the importance of spatial modeling in identifying the most efficient locations. The findings also indicate the presence of environmental and geomorphological constraints, such as slope steepness and lithological characteristics, which may affect project efficiency and should be considered in planning. Accordingly, the study confirms the effectiveness of geospatial modeling in decision-making support, improving water planning efficiency, and achieving sustainable water resource management in the study area