Watershed Management Using Multicriteria Decision-Making (Mcdm) With Weighted Linear Combination (Wlc) For Selection of Suitable Sites of Check Dams For A Data-Scarce Region

Abstract

Flash flooding due to short duration and high-intensity rainfall is one of the main issues in Panjgur District, a western region of Balochistan in Pakistan. Check dams are often proposed for reducing flood peaks, and flood volumes, preventing soil erosion and harvesting the surface water. The selection of the most suitable sites for check dams within the stream network is always challenging. This study is performed to identify the geographical location of the check dams for a proposed dam. A watershed boundary was identified by using the Archydro tools in the Geographical Information System (GIS) for a proposed dam. For identifying the suitable locations of the check dam, Multi Criteria Decision Making Analysis (MCDMA) technique is used, in which, nine geomorphological and topo-hydrological parameters (Drainage Density, Land use/Land cover, Stream Order, Topographic Wetness Index, Topographic Position Index, Slope, Terrain Ruggedness Index, Topographical Wetness Index, Stream Power Index, and Sediment Transport Index) were analyzed and classified using GIS. The weightage factor is assigned to each parameter. By using the Weighted Linear Combination (WLC) method, the locations of the check dams are identified. The results showed that the elevation changes from 1047 to 2058m covering an area of 4458.75km² in the proposed dam watershed. The slope ranges from 0^o to 59.63^o. The majority of the study area fell into quality zones with moderate to good potential for check dam construction. Based on the findings, 137 suitable locations for the check dams are identified. This study will help policymakers in the Panjgur District for the sustainable management of water management by expanding their understanding of the role of spatial data analysis.