Modeling of spatiotemporal variations of groundwater levels using different interpolation methods with the aid of GIS, case study from Ergene Basin, Turkey

Abstract

Monitoring of groundwater is important for sustainable use and planning of an aquifer. Water level information is the main source of information used to understand aquifer response. In this study, based on the geostatistical theory and ArcGIS geostatistical module, the data from 95 groundwater level observation wells for two periods as winter and summer, between 2011 and 2012, were used to model the temporal and spatial change in the groundwater level in the eastern part of the Ergene Basin. For this purpose, inverse distance weighing, radial basis function and ordinary kriging interpolation methodologies were used. Cross-validation, coefficient of determination, root-mean-square error and mean absolute error were used to determine the accuracy of different interpolation methods. It has been observed that the radial basis function method is more successful than the other methods in the modelling of the groundwater level in both periods, and the inverse distance weighing method is the most unsuccessful. Studies have also shown that the groundwater levels are low due to the excessive pumping of the wells drilled in the Organized Industrial Zone located in the NE of the study area. This decrease in the groundwater level up to 20-40 m is also observed in the east of the study area due to the pumping for irrigation purposes in summer.