Study of geological formations of Saravan plain and its effect on the quality of groundwater in the region

Aquifer of Saravan is considered part of the drainage basin of Mashkid river. Aquatic potential in different regions of Saravan Basin is different due to the diversity of formations and geological structures and other climatic and environmental factors. In this article, the relationship between qualitative and quantitative characteristics of water and the geological features of the region with regards to petrology and structures has been considered. Thereby, field study, reconnaissance, and the dispersion of geological formations of the determined region of Saravan was done using geological maps. Afterwards, 29 water resources including wells and qanats were selected for sampling and based on the analysis of the results of water samples, the dispersion maps and EC, TDS density of chlorine, sulphate, calcium, magnesium etc. were illustrated. Interpretation of the illustrated maps showed that the northwest of plain of Saravan from Allahabad toward the center of the plain and the western part of the Saravan-Khash road after ChahKhodabakhsh depicted low quality due to influencing factors on geological formations of low water quality and also in suburban areas of Saravan from Hoshak to Porrehkant apart from the effect of geological factors due to population density and the existence of urban sewage systems and at the end of the plain in Dehak area there is low water quality due to the location of underground water evacuation and the accumulation of the silts resulting from the flow of underground water. The best quality is reported to be of the water resources present in Chah Gomban in the south west and Chah Dashto and the Qanat of Gosh in the north of the plain and the surroundings of the granite formations of Koohsefid area in Gosht. It should be noted that the pollution hazard threatens all the water resources in the plain of Saravan.