胶州湾周边地下水和河水中^(222)Rn的分布特征及影响因素

Distribution Characteristics and Influence Factors of ^(222)Rn in Riverine Water and Groundwater Around Jiaozhou Bay

以胶州湾周边的洋河、大沽河、墨水河-白沙河以及李村河流域等为研究地点,于2011年9月底和10月初对研究地点的地下水和河水进行了调查和取样,分析和研究了地下水和河水中^(222)Rn的分布特征及其影响因素。从区域尺度上来看,岩浆岩地区以及断层发育地区的地下水和河水中^(222)Rn活度比新生代沉积岩地区的活度高。但是,局部水动力条件、水文地质因素、岩石与矿物学性质等因素可能在一定程度上影响某些相邻采样点地下水和河水中^(222)Rn活度。此外,地下水的补给程度和人类活动也是影响河水中^(222)Rn活度的重要因素。

As the research site of four watersheds around Jiaozhou Bay, this article investiga- ted and took samples of groundwater and riverine water on September and October 2011 to analysis and study the distribution characteristics of 222Rn activities and the influence factors in the water around Jiaozhou Bay. The samples were taken by special sampling bottle from RAD7 and placed about 15 min to reach the radioactive equilibrium status. Then the activi- ties of 222Rn can be measured by emanometer RAD7 and RAD-H2O The results show that the activities of 222Rn in groundwater and riverine water from the regional scale are much higher in the magmatic areas and the fault developed areas which contain higher concentra- tion of 238U decay series. Some adjacent sampling points vary widely both in groundwater and riverine water. The activities of 222Rn in groundwater and riverine water around Jiaozhou Bay mainly depend on the activities of 238U decay series from the nearby soil and rocks. Other geological factors such as fault development, hydrodynamic condition, hydrogeological fac- tors, petrological and mineralogical properties can also affect the activities of 222 Rn to some extent. In addition, the degree of supply from the groundwater and human activity are other two important factors to the activities of 222Rn in riverine water.