in order to optimized Analysis of underground water resources quality management of water resources (Case Study: Khansar watershed)

underground water resources are one of main sources for human needs, especially in dry areas. In addition, groundwater will not be affected by short-term droughts, and if used correctly can be a reliable resource for human needs. Khansar watershed, located in south- western of Harat city (in Yazd province), has two qanates with 414,383 m3 average annual discharge and 5 Springs with 507,729.6 m3 average annual discharge. For evaluation of water quality, in this area, no information is available so, in 2011, number of samples were taken and chemical analysis were carried on. The results showed that the input areas of Khansar watershed have high and appropriate water quality and are mainly Bicarbonat type. By moving the water toward the output, due to passing mineral geological formations, the water quality degrade. Minimum and maximum electrical conductivity are 445 and 3866 μm/cm, respectively. The major cation, based on abundance, are Sodium, Magnesium and Calcium. Analysis of the water quality for agriculture, on wilcox diagram, shows the suitability of all water samples except 4 and 6. These two samples are in the C4-S2 class and are unsuitable for farming, but appropriate for livestock. These results have strategic importance in decisions, for developing these areas.