Zoning groundwater quality for drinking using geostatistical methods Case Study: Arid Regions Mehran and Dehloran

Groundwaters in arid and semi arid areas have a particular importance. Understanding and proper utilization of these resources, especially in arid and semi-arid regions, is very important in sustainable development. Therefore, for the proper management of these natural water resources and appropriate use of them, information on spatio-temporal variation of their quality is essential. Today, research has found wider range of water quality and pollution of surface waters and groundwater issues is also included Methods for evaluating the quality of groundwater resources and recognition of appropriate locations for urban and agricultural water demand has been known as an important item in water resources planning. Ground-water management is more difficult than that for surface water resource management; therefore, there is a need to seek for reasonable and cost-effective procedures to determine the status of these waters.
In this study, groundwater chemical properties of arid and semiarid areas were investigated in Mehran and Dehloran using geostatistical methods. Geographic information system is one of the best systems that simplify and prompt access to many, varied data and their analysis, and helpful for managers to make an optimum decision. The software Spss17, Gs 9 and Arc GIS 10 is used for research. The study area is located in Ilam province. Arid and semi-arid Mehran and Dehloran This area is limited in 46°, 15' to 47°, 39' north of latitude and 32°, 2' to 33°, 37' east longitude. Area 8999 square kilometers and climate of the region based on dry Domarten, Ambruzhe middle of the hot desert, steppe and coupons method is Papadakys Mediterranean desert.
Sodium, chloride, sulfate, TDS and TH variables were evaluated. Semi variogram of parameters was computed by GS software and were fitted different models. After Survey normalizing data, variogram was depicted and interpolation was carried out by IDW method and kriging in GIS software. Criteria for the selection of appropriate models were lower RMSE and spatial structure stronger.
To investigate whether the parameters are normal, Kolmogorov-Smirnov test was tested on them and it was found that data on all the parameters of the normal distribution. results showed the superiority kriging method in comparison to IDW so maps were obtained by this method. The results indicate a strong correlation among water quality and the spatial structure of the data is Gaussian model. Finally, the zoning plan of the area was produced for drinking using fuzzy logic and Schuler classification. According to the final map, 37%, 13% and 50% of the area are suitable for drinking, relatively well and inappropriate respectively. As a result, the water quality in this area is not desirable for drinking. With overlay zoning map and the map of Hot spot analysis, it observed that areas with high concentrations of the warning threshold are located next to each other and in inappropriate zoning map class.
Groundwater an important part of the reproducible water ecosystems are the most often in arid and semi arid areas where surface water are very low are available. Ground Water quality change is due to management in use of groundwater resources. Main objective of this research was to investigate spatial variability of chemical properties of ground water. Mehran and Dehloran in plain facies gypsum, salt and limiting Gachsaran, especially in the central areas of the South East have great exposure. That due to solubility of salt and gypsum deposits limiting erosion and salt water flow and water would be undesirable. For this reason, changes made plain in the center of the formation and development of the South East Gachsaran, in plain end points will degrade water quality.Studies show that high levels of hardness and other elements of the central parts of the South East and North West incremental and to replace alluvial deposits at Gachsaran increases the hardness and other elements and in the southeastern plains maximum reaches its The main cause of the decline in water quality can be attributed to Gachsaran. Finally recommended to use geostatistical methods to be used as a useful tool for detecting groundwater quality and gradually replace the old method is the method in addition to the cost-efficiency water projects due to increased use of statistics.