Change of quality of surface and underground water due to saltdomes (case study:Biabanak of Semnan)

For studying the effects of salt dome on water resources of the area, elements variations and
qualitative parameters containing anions and Cations, HCO3+, Cl-, Na+, PH, SAR, EC, Mg2+,
Ca, SO4- were considered between years 1381-1388 and based of relative water resources
quality, downstream water resources can be deposited in different category from upstream
water resources using clustered diagrams and then Principal Component Analysis (PCA)
method determined that 70/67٪ of variations in underground water resources is due to the
changes in EC, Cl, and SAR parameters. Also, analyzing of the samples from 17 wells and
surface waters in the area in 1389 showed that 50/55٪ and 67/63٪ changes due to variation in
Cl, Na, and TDS parameters can be seen respectively which demonstrate the effect of salt
dome. In addition, statistic evaluations using SPSS software, showed a significant difference
with 1٪ level between elements and qualitative parameters, Cl, SAR, EC, anions and cations
and significant difference with 5٪ level in Na element on upstream and downstream of salt
dome. Hence, Vilox diagrams demonstrate a low quality of water resources for agriculture
uses that especially in downstream of salt dome these resources were found with very low
quality between years 1381-1388.Deep and surface soil studies of the area showed the high
level of saltiness of surface and firth and second depth soils in comparison with deeper ones.
Irrigation with salt waters can increase the saltiness and causes decreasing the efficiency of
agriculture field and as a result, economic efficiency and desertification can be increase. All
these show that Biabanak salt dome is a significant agent for construction of natural resources
in the area.

Change of quality of surface and underground water due to saltdomes (case study:Biabanak of Semnan) Keywords:

Salt Dome , Underground Water , Biabanak Area , Water Quality