Seasonal fluctuations in spatial variability of salinity and suspended solids in Shahrekord aquifer and its implications for drip irrigation

Shahrekord aquifer is the primary resource of water for various uses across Shahrekord plain. The main objectives of this study were to investigate the fluctuations in spatial variability and zonal mapping of conductance (EC), total dissolved solids (TDS), total suspended solids (TSS) and turbidity of Shahrekord groundwater during a year. Ninety-seven wells were sampled during four occasions (June, July, September, and November) in 2010. The mean of EC (both approximately 530 µS/cm) in June and July reduced to 370 µS/cm (P<0.05). The mean of TDS in June (400 mg/L) was higher (P<0.05) than the means in other samplings (300 mg/l). TSS decreased along with approaching the fall (P<0.05). A Gaussian variogram model described the spatial variations of EC and TDS in all sampling times while for TSS a spherical and sometimes an exponential model suited the best. According to the maps, TDS and TSS are highest in the southern half of the aquifer in all sampling occasions. On average, TDS is always suitable for drip irrigation while TSS indicates a moderate dripper clogging in most cases.