LAUSR

Identifying potential sites for water harvesting (WH) is a crucial task for efficient water resources management in arid regions. In response, this paper proposes a geographical information system-based model that combines fuzzy logic and analytic hierarchy process (AHP) to delineate suitable areas for constructing WH structures in arid southern Iraq. Based on a literature review and available data, five influential factors were selected to develop the model: hydrological soil group, land cover, surface runoff depth, slope, and distance to an intermittent river. A fuzzy logic-based approach was used to standardize the factors, and AHP was used to derive weights. The total score for land suitability was obtained from a linear aggregation of the products of fuzzy standard criteria and AHP-derived weights. The WH suitability levels obtained were classified into five different classes: unsuitable, poor, moderate, good, and excellent. The study revealed that 393 $$\hbox {km}^{2}$$km2 (18% of the area) is unsuitable or poor, 538 $$\hbox {km}^{2}$$km2 (26%) is moderately suitable, and 1167 $$\hbox {km}^{2}$$km2 (56%) is good or excellent for WH in the study area. Field data revealed that the only existing WH dam in the area is situated within an excellent WH-suitable zone, which indicates the capability of the developed model to identify areas suitable for different WH structures.