One of the important factors in the sustainability of the development of an area is the availability of sufficient and suitable water resources for various uses, which in addition to quantity, its quality status is also of particular importance. The phenomenon of climate change indirectly affects the quality of surface and groundwater by affecting rainfall, temperature and the amount of sediment produced. Therefore, eva‎luating the phenomenon of climate change and its possible consequences as well as recognizing the effects of land use change on the hydrological responses of the basin is the key to determining the appropriate strategy in the sustainable development of watersheds. The present study was conducted to investigate the effect of climate change trends on quantitative and qualitative parameters of surface and groundwater resources in Plasjan watershed located in Isfahan province in the period of 1398-1398. For this purpose, temperature and precipitation statistics of synoptic station owners during a 20-year statistical period, discharge data of Alexandria basin located at the outlet of the basin, surface water quality parameters and quantitative and qualitative parameters of wells located in the study area were used. CZI, ZSI, SPI indices were used to study meteorological drought and SDI index was used to study hydrological drought. Initially, in order to study the drought and wet season in the region, standardized discharge data (SDI) with drought indices in 6, 12, 24 and 48 months were examined by Pearson correlation method. The results showed that there was the highest correlation between 12, 24 and 48 month time scales. The results of correlation between changes in meteorological drought index (SPI) and changes in river discharge and river water quality showed that with increasing discharge, the concentration of% Na, CL, SO4 and anion aggregates, as well as Ec, SAR, TDS, PH decreases. Also, the results of correlation between precipitation and temperature and river flow and piezometric level showed that there is a significant relationship between river flow and piezometric level, while no significant relationship was observed between climatic parameters and groundwater quality parameters, although with increasing water level compared to Ground surface, the concentration of qualitative parameters increased. Finally, Pearson correlation was obtained between land use area data and quantitative and qualitative parameters of surface water and groundwater. The results showed a decrease in water quality following a decrease in rangeland use and an increase in urban use in drought and an increase in agricultural use in wet season. The study of land use changes on groundwater quality parameters showed that in the dry period of the year with the change of forest and rangeland use to barren land use, the concentration of some elements has increased. According to the obtained results, it can be stated that the process of changing climatic parameters alone does not affect the quantitative and qualitative parameters of surface water and in addition, land use change in Plasjan watershed is also effective. Due to the fact that there are two systems in the Plasjan River that drain the aquifer and feed the aquifer. Therefore, change in each has an effect on the other

6/21/2022 12:00:00 AM

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