Identification of Potential Check Dam Sites Using Multicriteria Decision Support System: A Case Study of Wana District, South Waziristan

Abstract

Decreasing water resources is one of the main concerns throughout the world and specially in Pakistan. South Waziristan, district of Pakistan is facing severe water shortage from the past few decades. The best way to control scarcity of water resources is construction of water harvesting structure at a suitable location, which need very critical measure considering many criteria for the selection of sites for harvesting structure. Using GIS and remote sensing we can select optimal sites for check dam very efficiently and effectively. In this study we adopted GIS and Multicriteria decision analysis using Analytical Hierarchy Process and Weighted Linear Combination for locating appropriate locations for water harvesting check dam in WANA city of district South Waziristan Pakistan. Various confined layers i.e. Land Cover, Soil, Slope, Precipitation, Geology, Drainage density, fault line and road networks were created and then assigned weight to each layer according to their importance for check dam and apply Analytical Hierarchy Process and Weighted Linear Combination for finding a suitable zone for check dam first. The AHP method give us significant results than WLC, while validating with existing check dam sites of the study area. Analytical hierarchy process gives us result ranging from high potential to low potential zone which was classified into three zones i.e., low potential zone, moderate potential zone and high potential zones. Out of a total area of 3742 sq.km, high potential zones occupy 805 km2 (21.24%), moderate potential zones occupy 1697 km2 (45.35%), and poor potential zones occupy 1240 km2 (33.13%). After selecting suitable zones, sites for check dam was marked by using stream order which was created from DEM using ArcMap. 2 nd and higher stream order was chosen for check dam. Out of the suitable zones a total 28 suitable sites for check dam were marked by physical visits to the study area and using google earth pro in high suitability and moderate suitability zones.