Selecting the Best Geostatistical Method for Mapping the Spatial Distribution of Electrical Conductivity of Water for Using in Agriculture: A Case Study of Ravansar Sanjabi Region, Western Iran

Groundwater is one of the main important sources of irrigation water. Thus, special attention should be paid to these sources to prevent their contamination. Geostatistical techniques reduce the number of the necessary samplers and increase the accuracy of estimates. Therefore, this method could be used as a convenient method for studying groundwater quality. The electrical conductivity is an important method for qualitative estimation of groundwater. Therefore, the present study was carried out to investigate the different approaches and to find a suitable interpolation method in electrical conductivity of groundwater to find land area for farming in Ravansar Sanjabi. Hence, Groundwater samples were taken from 903 wells within the study area. To compare the two statistical methods for interpolation (deterministic and Geostatistic), Arc GIS 9.3 was used. The results showed that among these methods, the radial radiation and ordinary kriging with Five-sided model have the highest accuracy. Moreover, based on the results of the zonation of groundwater, 20 percent of the study area is of high suitability for agriculture, 66 percent of this land is of good suitability and 14 percent of the study area has a high suitability for agriculture.