Geographical and statistical analysis of groundwater quality changes in Bam Plain

Document Type : Research Paper


1 University of Tehran

2 Department of Arid and Mountainous Reclamation Regions, Faculty of Natural Resources, University of Tehran, Karaj, Iran.

3 College of Interdisciplinary Science and Technologies, School of Energy Engineering and Sustainable Resources, University of Tehran, Tehran, Iran.



Increasing population growth and thereby increasing exploitation of ground water resources has led to not only decreased quantity but also reduced quality of these valuable resources. Therefore, necessity of studying the quality of water in these areas can help proper management of these water resources. The aim of this study was to determine the groundwater quality variables using principal component analysis and then to evaluate the efficacy of the three kriging models namely simple kriging, universal kriging, and ordinary kriging in interpolation of the most important qualitative variables defined in Bam plain. For this purpose, of the 60 existing wells, 40 wells with good distribution in the study area were selected randomly as for training and the remaining wells were used to test the models. Results of principal component analysis showed that the two variables EC and TDS as the main variables explained the highest changes in variance of other water quality variables. Results of interpolation based on these two parameters showed that ordinary and universal kriging were relatively same in estimating the salinity in the training step, but in the testing step, ordinary kriging estimate better than universal kriging based on RMSE and MAE coefficients. But in interpolation of variable TDS in both the training and testing steps, ordinary kriging had the best performance compared to the two other methods. Interpolation results based on these two variables also showed that the salinity in the north and northeastern parts of the plain in two ordinary and universal kriging was higher than other places indicating a good conformity with changes in land use.


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