Study of Hydrochemical Characteristics of Birjand PlainGroundwater Resources
For determining the hydrochemical properties of the Birjand plain groundwater, 23 samples are collected from pumping wells and analyzed in hydrologic laboratory. Some properties such as PH, EC, and temperature are also measured at wellhead. Then, for determining the quality of water for drinking, agricultural and industrial uses, the resultant data are plotted in relevant hydrochemical diagrams. They show that water of eastern and northern parts of plain is not suitable for drinking purposes, whereas, the water of southern part is permissible. Of course, the heavy metals and microbial contaminant are not considered in this study. From the agricultural point of view, from 10 samples collected from northern part of the plain, 7 samples have EC more than the maximum EC used in Wilcox diagram, 2 samples lie in class C4S2 and one sample in class C4S3, while, from 6 samples collected from southern part of the plain, 3 samples lie in class C4S1and 3 others in class C3S1, which shows only the water of southern part,, are suitable for agricultural purposes. By considering the Ryznar stability index and Langelier saturation index, the water of most wells are incrustal. The type of water in southern part, is sulfate and chloride, whereas, for the other wells it is only chloride.