investigating the effects and consequences of excessive extraction of underground water from dashte-mashhad reservoir with an emphasis on water ec variances

dashte-mashhad reservoir provides the water supply needed for irrigating 120 acres of agricultural lands and also the soft water for people living in mashhad, chenaran, golbahar and a number of villages in the region. the deep wells of the region have been using the water stored in this reservoir since 1350 in a rate which exceeds that of water being imported to it, hence the decrement of the water supply. the average reduction rate is more than one meter per year which has consequences including reduction in the wells’ water output, lowering the ground level and the increment of minerals in the water with regard to the last point, it should be mentioned that the level of ec minerals in the water of chenaran region has increased by 250 mho in centimeter during 22 years (1363 to 1385). in addition, for each meter of reduction in the height of underground waters in the same period, the level of ec (26 at the beginning) has increased to 95 mho in centimeter. the method of research is inductive and causal and the final analysis is done based on correlation analysis of the data extracted from a set of maps, hydrographs, and chemo graphs. it can be argued that the over-extraction of the reservoir will make it very salty and eventually unusable.