Zonation of Superficial Karst Development Using Fuzzy Logic Method (Case Study: Shirez Karstic Masses)
Masoomeh Rajabi, Asadollah Hejazi, Somayeh Almasi Ghobadian
The karstic masses play key role in providing water for the settlements and agricultural land surrounding them. In Kermanshah Province, most of the altitudes consist of carbonate formations and the Shirez karstic masses are of them and located in the Zagros thrust zone (or High Zagros zone). This karstic mass has a potential to develop the karst due to the geological, hydrological and geomorphological conditions. In order to investigate the development of karst in the studied area, the layers of geology, elevation, slope, aspect, precipitation, temperature, distance from fault and vegetation were used. Moreover, in order to produce the fuzzy maps of the affecting factors, Arc GIS software and membership functions of Fuzzy large, Fuzzy small and Fuzzy linear were used. Finally, the fuzzy algebraic sum, product and gamma operator were used to produce the final map. The results of present study show that the gamma operator with a value of 8% has a higher accuracy than other operators and according to it, 0.24 of the zone studied is placed under the developed karstic category. The developed karstic zones have a great influence on the absorption of atmospheric precipitation and the feeding of aquifers; therefore, it is necessary to protect these areas in order to prevent the pollution of groundwater.