Investigation of the effective elements in water resource exploration of the ‎hard formations, case study: Lar catchment

Information on the hierarchical importance of the factors influencing on the spatial distribution of springs in a watershed are required for the development of the water quality and quantity management plan. In this regard, we address the integration of GIS and decision support tools, for zoning prone areas. In this research to determine hierarchical importance of the elements on the water resources development in Karst regions, first with literature review and field studies, the effective parameters in occurrence of spring were selected. Then thematic layers of these parameters in GIS environment were prepared. Each layer separately crossed with the spatial distribution of spring's layer and priorities of each sub layer with respect to each other in terms of frequency of spring's occurrence were determined. Finally, using the analytic hierarchy process, factors affecting the occurrence of this phenomenon and the weight of each factor was calculated by Expert Choice software. Results showed that the weight of the top layer assigned to the lithology and carbonate substrate alone formed 54% of the weight of this layer. The next layers in order of importance were including the layer of the slope and elevation classes, structural elements, lineaments, limestone contact and drainage layer. Potential map prepared by this method, match 76 percent with the spatial distribution of springs.