| چکیده انگلیسی مقاله |
The flood of April 2018 in Khuzestan province is one of the rarest floods that have occurred in this province, which has left a lot of environmental and economic damage. In the current research, the effect of this flood on the quantity and quality of groundwater in the Shush aquifer has been investigated. For this purpose, hydrochemical sampling was carried out from the surface and groundwater sources of the Shush plain in May and October 2018 (flood and dry periods) and the concentration of main ions, nitrate and stable isotopes of oxygen-18 and deuterium were measured. Quantitative and qualitative analyzes have been carried out using aquifer representative hydrographs, combined diagrams, Piper, Schuler and Wilcox and isotopic studies. The results of the representative hydrograph of the aquifer showed that the changes in precipitation have caused the level of the reservoir level to increase by about one meter at the end of the 2018-2019 (September 2019) water year compared to the end of the 2017-2018 (September 2018) water year. The reason for the decrease in the concentration of qualitative parameters in the southern parts of the plain and in the direction of the groundwater flow is the increase and accumulation of floods in the downstream parts of the aquifer, which is associated with the decrease in the depth of the water table in these areas. Combined graphs of the flood period show the relative increase of water-soluble substances compared to the dry period. This increase in the main ions can be attributed to the strong nutritional pulses of the flood, which has disturbed the chemical balance of the groundwater and mixed it with unstable sediments in the aquifer. Based on the isotopic results, in the flood period, all the samples follow the local precipitation line, which indicates the aquifer's feeding from the flood, and in the dry period, due to evaporation, the samples are more scattered than the global precipitation line. |
