A New Approach to Monitoring Groundwater/Surface Flow Relationships, Using 222Rn and SF6

天然222Rn和故意引入的SF6的测量可以准确地检测和量化地下水输送到河流的流量。同时测量222RN和SF6的实验将在佛罗里达州的圣达菲河进行。在河流中检测到异常高水平的222Rn将允许确定地下水输入的位置。观测到的SF6和222Rn之间的变化将用于确定精确的气体交换率，这需要估计地表排放的地下水成分。气体交换速率，可以表示为再生系数，也是评价溪流水质的决定性因素。因此，222Rn和SF6的测量将产生另一种用于评估水生系统水质的地球化学技术。在222Rn调查期间，在一次主要降水事件发生后，对从Sante Fe采集的水样的D/H和180/160比率进行测量，当降水产生的地表径流与井内地下水成分之间的差异最大时，将为基于222Rn数据的地下水输送估计提供独立的检查。这项提议的研究将通过建立一种强大的新的地球化学技术来检查地下水和地表流之间的相互联系，从而使水文学家和水资源管理者受益。此外，该研究将提供一个传统方法难以获得的水文和水质数据库。

The measurement of natural 222Rn and deliberately introduced SF6 can be used to accurately detect and quantify groundwater delivery to stream flow. Experiments, involving the simultaneous measurement of 222RN and SF6 will be conducted in the Santa Fe River in Florida. The detection of anomalously high levels of 222Rn in the stream will permit the identification of locations of groundwater input. The observed variations between SF6 and 222Rn will be used to determine accurate gas exchange rates, which are needed to estimate the groundwater component of surface discharge. The rate of gas exchange, which can be expressed as a reaeration coefficient, is also a determining factor in assessing water quality in a stream. Thus, the measurement of 222Rn and SF6 together will yield another geochemical technique for assessing the water quality of aquatic systems. Measurements of the D/H and 180/160 ratios in water samples collected from the Sante Fe during a 222Rn survey following a major precipitation event when the difference between the precipitation derived surface runoff and the well integrated groundwater component is maximized will provide an independent check on estimates of groundwater delivery based on the 222Rn data. The proposed research will benefit hydrologists and water resource managers by establishing a powerful new geochemical technique for examining the interconnections between groundwater and surface flow. In addition, the research will provide a hydrologic and water quality data base not easily obtained by conventional methods.