The use of Kriging Techniques with in GIS Environment to Investigate Groundwater Quality in the Amman-Zarqa Basin/Jordan

The Kriging techniques are called the best linear unbiased estimator since it tries to have a mean residual error equal to zero. It aims to minimizing the variance of the errors and hence is a strong advantage over other estimation methods like inverse distance weighting or moving average. In this study, the ordinary kriging techniques were used to estimate groundwater quality parameters (Ca2+, Mg2+, Na+, K+, Cl- and NO3-). It was found that the spatial interpolation of groundwater quality of the study area poses various problems due to the complex impact of cultivation and urbanization systems of the study area. Testing of various methods and parameters, by comparing and ranking their cross-correlation errors, show that ordinary kriging method using the different semivariogram models provides the overall good results. Also, most of the groundwater quality parameters have moderate spatial structure except NO3 and Ca that have a strong spatial structure.