The effects of geological formations on groundwater quality with ‎application of Boulian logic, case study: Bajestan Watershed Plain‎

Underground aquifers are one of the main sources of water supply in most parts ofIranwhich are affected by natural and manmade factors in recent decades. Land and geological formations are from the natural factors in any region. In this study, the investigation of the quality of groundwater resources and their correlation with geology formations were considered. For this purpose, using the geological map of the area geological formations were extracted. Then, to determine the water brigade, the qualitative data of 76 operation wells and three control operation wells, were entered in the Chemistry software. Next, formations were classified according to the type of production and the effects of their dissolution (quality); in the next step, buffers in intervals of one, three, five, seven and 10 km were created around wells and their layers were overlaid with geological maps. The t-test results showed that at 95%, at one, three, five and seven km from the wells, the impact of formations is significant on operation wells, but, at a distance of 10 km and with increasing distance, this effect was less and significant effect there is not in this respect, but, their total impact of non-quaternary formations increases on the wells. Also, the results from Boulian logic showed that that formation (Qt2) has the most spreading near the wells, including alluvial fans and young alluvial sediments which are the original location for feeding aquifers. But, by increasing the distance from the wells, the impact of non-quaternary formations like Cretaceous limestone and Batholith rocks (volcanic) that have the ability to produce water Brigade of sodium chloride and carbonate increases.