Modern irrigation development: hybrid MCDM-GIS framework for identifying potential areas and feasibility assessment (theory and application in a semi-arid region)

Due to limited water and soil resources in arid and semi-arid regions, improving irrigation efficiency and both physical and economic water productivity is essential. Proper study, design, implementation, operation, and maintenance of modern irrigation systems, together with water management on farms, are key approaches to achieve Precision Agriculture and Sustainable Development. This research aimed to present a hybrid method to identify suitable areas for implementing modern irrigation systems, and to propose the most appropriate system type by developing a hybrid MCDM-GIS framework. To comprehensively assess the main influencing factors, 16 sub-criteria were selected under six criteria: water resources, soil, climate, social, economic, and cropping patterns. Five irrigation system options were considered: Fixed Classic with movable sprinklers, Wheel Move and Gun sprinklers (SpCWG), Center Pivot and Linear irrigation machines (SpCL), Surface Trickle Irrigation (TrGT), Gated Pipes (SuGP), and Subsurface Trickle Irrigation (TrSS). The criteria and sub-criteria were defined using the Delphi method and validated with the CVR index. The AHP-TOPSIS hybrid model was then applied to determine the weight of the sub-criteria. Classification and information layers were prepared for each sub-criterion, and after applying the weighting coefficients, and overlaying the layers, a map of suitable areas for each irrigation system was generated. Finally, for each well and aqueduct water source, irrigation systems were identified in order of priority. A case study was conducted in Arak County, central Iran, with an arid and semi-arid climate and irrigation-based agriculture. The results from the AHP-TOPSIS integrated framework showed that in the SpCWG system, water resources and climate had the highest weights (0.472 and 0.246, respectively). Water electrical conductivity, chlorine, and long-term maximum wind speed strongly influenced the SpCWG system. For the SuGP, SpCL, TrSS, and TrGT systems, the soil criterion had the highest weights (0.514, 0.45, 0.315, and 0.31, respectively), followed by water resources (0.175, 0.229, 0.315, and 0.31, respectively). In the soil criterion, soil texture and land slope were the most important sub-criteria, while in the water resources criterion, water electrical conductivity and chlorine were most significant. The TrGT system was most frequent as the first priority for lands irrigated by 600 wells (44%) and 78 aqueducts (46%). Overall, the proposed hybrid method effectively identified suitable areas for modern irrigation systems and recommended the appropriate system type.