Geostatistical analysis of groundwater levels in the south Al Jabal Al Akhdar area using GIS

The geostatistical analysis of the groundwater levels from 95 water wells in south Al Jabal Al Akhdar area north east Libya was conducted according to GIS methodology. Water level data firstly was explored for normality using exploratory spatial data analysis (ESDA) tools, as the transformation was required to drive the data into normality. Spatial interpolation also was carried out using geostatistics ordinary kriging model through out modeling semivariogram and covariance. Afterward the surface was generated for water level map, which shows the groundwater is at a deeper level in the northern parts of the study area. However, it gradually becomes shallow in the south. Mapping potentiometric surface was conducted from digital elevation model (DEM) and groundwater level raster, where it shows high values in the northern parts of the study area, this high values decreases to the southern parts of the area. Furthermore, four water divides were defined from the potentiometric surface.