effect of drought on qualitative and quantitative parameters of zahedan plain aquifer

the effect of drought indices on hydrostatic variations and qualitative parameters of the zahedan plain's aquifer was investigated. for this purpose, 12-year statistics from observational and piezometry wells in the plain, the drought index of percentage normal )pn), standardized precipitation index )spi(, and 30-year precipitation statistics of zahedan station were used. results revealed that the pn index had a greater variety than spi. the aquifer hydrograph showed a rise of 1.37 m in water level from the year 2002-2003 to 2013-2014. considering the drought conditions in the plain, this rise in the water level can be attributed to the reduced water extraction from the aquifer, because the water requirement of zahedan city was supplied from other sources, viz. chah-nimehs. also, there was a significant correlation between the parameters of anion, tds, and na+ with spi. however, pn index did not have any significant relationship with the quality parameters. there was a significant correlation between water level balance and spi only at the level of 1%.