Groundwater Hydro-chemical Characteristics Analysis And Prediction Study On The Jinghui Irrigation Area

Jinghuiqu Irrigation Area is located in the centre of Guanzhong Plain, where the groundwater is the main water sources of irrigation and water supply. So, researching the hydro-chemical characteristics of the groundwater and forecasting it could show us a deeper understanding of the changing trends of groundwater quality in Jinghuiqu Irrigation Area, it also provide a scientific basis on groundwater resources utilization and eco-environmental protection. At the same time, it has important significance for the sustainable development there.This paper based on the analysis of local geological, hydrological data, then collected and analysis water samples, applied the theory and methods of hydrogeology, hydrology and geochemistry, and studied the hydro-chemical characteristics in Jinghuiqu Irrigation Area. On this basis, this paper established of a un-interval gray system groundwater quality prediction model and predicted groundwater quality in the years of 2010 and 2015 with application of gray system theory.The research showed that: type of water chemistry in the whole irrigation area is rather complicated, salinity of the groundwater is gradually rise from northwest to southeast, the area of the high salinity of groundwater is expanded every year, and the equivalent line of salinity is over to the east in the un-exploitation period, groundwater chemistry has the trend of sodicity, the type of water chemistry is more and more complicated and evolution of water quality is worse and worse. research shows that:: the TDS of groundwater irrigated area increased gradually from west to east;Comparison of water quality characteristics in different seasons, we can see that the type of water chemistry and TDS between the exploitation period and non-mining period in groundwater irrigation area are quite different, manifested as:In the mining period, the type of water chemistry of groundwater is for HCO3-type water, TDS period compared to non-exploitation is generally low; but the groundwater chemical types transform to the SO42-concentration, TDS is higher in non-mining periodThe result showed that: in the case of exploitation mode,exploitation,agricultural operations and pollution discharge unchanged, the irrigation area ground water quality evolution of the overall trend is worsening.