Combination using of qualitative parameters inaquifer and watershed of Mosian plain in order to determine the aquifer qualitative impacts on surface flow

Determining the long-term qualitative conditions for water resources is very important in areas facing water shortage. By determining the quality of water resources, it is possible to examine the sustainability of resources and its importancein long-term planning. Iran is also considered to have a shortage of water due to its geographical location, including arid and semi-arid regions. Therefore, in this paper, determination of the quality of water resources of fertile plains around Musan village in Iran was studied.For this purpose, the data of watershed and aquifer were collected during 10 years period and the outlyingdata was removed using the box diagram.Statistical analysis carried out in Student'st-distributionat confidence levelof 95% showed that the maximum amount of hardness, TDS, EC, Ca, NO3, HCO3, SO4, CL, Mg and Na in the Telezi River are 70.5, 124.5, 201, 91.1, 7.5, 82.3, 15.2, 11.7, 3.8 and 14.9 mg/liter, respectively. According toWHO and the drinkingwater standards of Iran (No.1053), it can be used for drinking. This analysis also demonstrated the appropriate quality of groundwater resources. Based on the long-term collected data, changes in quality trend of the catchment and aquifer were investigated, which based on the Mann-kendall test, the decline trend in quality for all parameters of the catchment (except SO4and Mg) was obvious at 5% significance level, while in the aquifer, just reduction in the TDS quality of the groundwater resources was observed. According to the similar results between the catchment and aquifer, the hypothesis based on the relationship between these resources was raised which investigated by the finite element method. It was found that the aquifer of the plain has been influenced up to the high of 70 meters from the watershed.