Study Of Hydrochemistry Characteristics And Submarine Groundwater Discharge At South Coast Of Lai Zhou Bay

The Laizhou Bay in Shandong is one of the worst areas which was intruded by sea(salt) water in China. A direct consequence of its long-term groundwater resource imbalance is taken up groundwater levels continued to decline, resulting in the interface between salt and fresh water move to landward, up to now in the study area is formed a continuous intrusion belt, which pose a greater hazard for the local ecological environment quality, industrial and agricultural production and people’s lives. Thus, through the analysis of hydrochemical characteristics of the groundwater as well as quantitative estimate of submarine groundwater excretion can provide theoretical and methodological reference for future. Furthermore, provide more specific, intuitive decision-making basis for the rational development of various groundwater resources in Laizhou Bay region and promote a great significance of sustainable development to groundwater.The Study choose Changyi City in Weifang as the study area, testing the groundwater and surface water. To monitor the groundwater level, water temperature, and conductivity data, laid a monitor profile in the north of Changyi city in 2014 and 2015, the main conclusions are as follows:1、The north of Liutuan town in Changyi along the Weihe River direction has a southward saltwater intrusion trend, salt water and brine in northern also has a southward trend, and east to west, the distribution of space on the strip. The range of TDS is between 0.39g/L~64g/L, with an average of 9.38g/L.2、By analysising Na+, Mg2+, Ca2+, Cl-, SO42-, HCO3- and other content in groundwater and surface water, we can see that the sea(salt) water was intruding, and at the initial,the hydrochemical characteristics changed; while in the longer duration of the invasion process stage, hydrochemical remained stable. When freshwater and brine mixing occurs, causing the precipitation of gypsum or dolomite, resulting in a reduction in Ca2+ concentration. The results of δ18O and δ2H test show that the groundwater impacted by the evaporation, and the runoff is a major source of deep groundwater recharge.3、The brine has a relatively low 37 Cl value, because of the saltwater intrusion in the north of the study. And some saltwater points in deep layer distributed around the saltwater point, indicate that deep phreatic water has been affected by saltwater intrusion. The test results of CFCs show that, deep groundwater is older than shallow groundwater. But there is an exception, its deep groundwater is younger, it is belong to modern water. The reasons are a large number of underground brine extraction in local, resulting in the of groundwater’s update rate is faster.4、The total SGD and inflows in the intertidal sectional were 80.4 m3/d/m and 108.5 m3/d/m. The error of water level to a certain degree influences the result of SGD and inflow.