Spatio-Temporal Trend Analysis of the Depth and Salinity of the Groundwater, Using Geostatistics Integrated with GIS, of the Menemen Irrigation System, Western Turkey

Abstract

A rise in the level of the water table to the effective root zone results in decreasing yields because of salinity and sodicity, and eventually such areas cannot be cultivated. For sustainable irrigated agriculture, the salinity and level of the water table should be monitored continuously and held within tolerable limits. The aim of this study was to evaluate spatial and temporal changes in the salinity and level of the water table in the command area of the Menemen Irrigation System for the years 1995-2006 using geostatistical methods integrated with GIS. The salinity and level of the water table in the study area were evaluated in terms of both spatial and temporal variation. Trend analyses of these values were performed using the Mann-Kendall test. The non-parametric Sen’s Slope Estimator was used to calculate the magnitudes of the trends. A risk map of the study area was formed by performing geostatistical analyses by GIS, based on the intensity of the trend. It was observed that there was no current problem with the depth and salinity of the groundwater in the study area in general, but that there would be a potential risk of a problem in the future.