TITLE:
Application of GIS and Multi-Criteria Decision Analysis for Locating Suitable Rainwater Harvesting Zones in Kabul Metropolitan Area, Afghanistan
AUTHORS:
Obaidullah Rahimi, Emal Wali, Ulrich Dittmer
KEYWORDS:
Kabul Metropolitan Area, Water Scarcity, Rainwater Harvesting, MCDA, AHP
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.16 No.2,
June
16,
2026
ABSTRACT: In recent years, Afghanistan has been suffering from water shortages, and around one-third of the population lacks access to stable water sources. The Kabul Metropolitan Area (KMA) in particular has faced increasing water scarcity challenges due to rapid urbanization and the absence of adequate water conservation infrastructure. Alarmingly, UNICEF Afghanistan has issued a warning that Kabul’s groundwater could run dry by 2030. To address this critical issue, this study aimed to identify potential Surface Rainwater Harvesting (SRWH) sites within the KMA using an integrated approach combining the Analytical Hierarchy Process (AHP) and Geographic Information System (GIS). In this study, rainwater harvesting refers specifically to the collection of surface runoff from natural catchments rather than rooftop systems. The proposed methodology was implemented at a large urban metropolitan catchment scale in KMA with an area of 1629.2 km2, located in the existing Kabul city and the Kabul New City areas of Dehsabz and Barikab in the northeast. Based on the comprehensive literature reviews, FAO guidelines, and the expert opinions of Afghan professionals with field experience in the region, Six biophys-ical criteria were selected such as precipitation (average annual), slope (derived from DEM), soil type (based on soil texture), land use/land cover, lithology (clas-sified based on rock types), and drainage density (calculated as total stream length per unit area). The experts provided pairwise comparisons and feature ratings to determine the weights. Then, in ArcGIS Pro, the weighted overlay analysis was applied, assigning the highest weight to rainfall (24%) due to its critical influence on RWH suitability, and the lowest to drainage density (11%). The weighted overlay results indicate that approximately 40.5% of the study area falls within the high suitability class, 30.9% within moderate suitability, and 28.5% within low suitability, based on the classification of the composite suitability index. These results highlight the application of a GIS-AHP model that may be used to determine potential areas for harvesting rainwater, not only in this region but also in other semi-arid urban areas with restricted information.