Document Type : Research Paper
Author
Researcher staff - Soil Conservation and Watershed Management Research Institute
Abstract
The protection and enhancement of water resources, as well as the collection and storage of water with minimal losses, are among the effective measures in areas with arid and semi-arid climates. Groundwater dam technology is recommended as a suitable solution for the management and development of water resources in these climates. This paper explores the feasibility of constructing a groundwater dam in the sub-basins of western Semnan Province using hierarchical analysis and geographic information systems (GIS). Based on the nature, performance, and objectives of groundwater dams, and through a review of the literature, the necessary conditions, characteristics, and criteria for selecting suitable locations for constructing these types of underground hydraulic structures were identified. To identify areas with the potential for groundwater dam construction, criteria and characteristics related to geology, hydrology, water resources, topography, and geometry were utilized. Initially, some areas were eliminated by absolute criteria or classified as unsuitable in the decision-making criteria. Using absolute criteria such as fault zones (100 to 200 meters), water source buffers (500 meters), stream rank (1 and 2), slope percentage (over 8%), and the lithology of geological formations (alluvial and gypsum and saline layers) as exclusion criteria, areas were hierarchically and stepwise eliminated using Boolean logic within the GIS framework. After weighting, all decision-making and selection criteria were classified and internally scored based on their impact on creating favorable conditions for the desired structure, and prepared as an information layer in raster format with a pixel size of 25 meters in the GIS environment. Following the elimination of unsuitable areas through exclusion criteria, prioritized suitable regions were identified by overlaying the layers related to the classified criteria and summing the scores in each area. Results showed that over 20% drainage of the surface area of the western Semnan Province has the potential for the
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