Engineering geomorphological study to assess the potential for artificial lake construction in the agricultural areas of the Selenge River Basin, northern Mongolia

Сэлэнгэ мөрний сав газрын хөдөө аж ахуйн бүс нутагт хиймэл нуур байгуулах боломжийг тодорхойлох инженер геоморфологийн судалгаа

Abstract

Under the intensifying impacts of global climate change and the increasing frequency of droughts and harsh winters, the agricultural regions of the Selenge River Basin in Mongolia are facing persistent water scarcity. This study aims to identify and evaluate geomorphologically suitable sites for artificial lake construction in order to strengthen water supply, ensure environmental balance, and meet domestic water needs within the framework of Mongolia’s national initiative “333 Lakes, One District–One Lake.” A suitability assessment was conducted through spatial analysis based on a 30 m resolution Digital Elevation Model (DEM), employing the Analytical Hierarchy Process (AHP) method. From an engineering geomorphological perspective, the evaluation considered not only topography, hydrology, precipitation, and soil conditions but also additional land-use factors. The results reveal that 10.12% of the study area is classified as highly suitable, 69.45% as suitable, and 13.34% as moderately suitable, while the remaining 7.09% is either unsuitable or restricted by land-use constraints. Based on the comprehensive assessment, nine representative potential sites for artificial lakes were selected. For each site, potential irrigable areas, domestic water supply capacity, and livestock watering availability were estimated, and a general economic evaluation of potential water sources and dam construction costs was conducted. This study emphasizes that incorporating engineering geomorphological analysis and Geographic Information System (GIS)-based approaches provides essential scientific support for site selection of artificial lakes, thereby contributing to sustainable agricultural and pastoral development in the Selenge River Basin.