Geochemical Tracing of Potential Hydraulic Connections between Groundwater and Run-Off Water in Northeastern Kansas, USA
Geochemical Tracing of Potential Hydraulic Connections between Groundwater and Run-Off Water in Northeastern Kansas, USA
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美国堪萨斯州东北部地下水与径流水之间潜在水力联系的地球化学追踪
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
S. Chaudhuri
中科院分区：
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作者：
N. Clauer;I. Techer;S. Chaudhuri
这项研究的重点是确定当地低地含水层与附近一条小溪和两条主要河流的径流水在美国堪萨斯州东北部及其周围的潜在水力连接程度。它是基于集体证据，结合了水的几种主要和微量元素的含量及其氧、氢和锶的同位素组成。调查地区位于堪萨斯州康扎草原以西几英里处，这是美国指定的定期监测生态和环境状况的地点。两河溪流径流水的δ18O和δD与当地含水层地下水的δ18O和δD几乎相同。相对于一般大气水线，δ18O-δD数据有向相对较低的δ18O值偏移的趋势，大陆内盆地的次表层水也是如此。观察到的这些水的稳定同位素组成排除了植被蒸发蒸腾过程或与直接矿物-岩石基质相互作用的任何重大影响。从靠近堪萨斯河的井中收集的含水层水的87Sr/86Sr比值与河流水明显不同，证实了含水层和河流之间缺乏水力相互作用。相反，距离堪萨斯河相对较远的井中地下水的87Sr/86Sr比值、Sr含量和Sr/Ca比值与河水相似，表明这些含水层与河流之间存在水力联系，并且没有受到植被的任何影响。研究区北部的夏山附近也发现了地下水供应，除了其西部边界，在那里含水层水与储层岩石之间或与小溪和河水之间没有明显的相互作用。地下水的87Sr/86Sr特征也表明研究区内存在一个主要的东西向流动系统，该系统可分为三个实体，以及沿三哩溪向堪萨斯河的补充南北趋势。
This study is focused on establishing the extent of potential hydraulic connections of local lowland aquifers with the run-off waters of a nearby creek and two major rivers in and around Fort Riley in northeastern Kansas, USA. It is based on collective evidence by combining the contents of several major and trace elements of the waters with their oxygen, hydrogen and Sr isotopic compositions. The area of investigation is located a few miles to the west of the Kansas Konza Prairie, which is a United States designated site for regular monitoring of ecological and environmental configurations. The δ18O and δD of the run-off waters from the two rivers and the creek, and of the ground waters from local aquifers are almost identical. Relative to the General Meteoric Water Line, the δ18O-δD data have a tendency to deviate towards relatively lower δ18O values, as do generally the sub-surface waters of intra-continental basins. The observed stable isotope compositions for these waters preclude any significant impact by either an evapo-transpiration process by the vegetation, or an interaction with immediate mineral-rock matrices. The 87Sr/86Sr ratios of the aquifer waters collected from wells close to the Kansas River were markedly different from those of the river waters, confirming a lack of hydraulic interactions between the aquifers and the river. On the contrary, ground waters from wells at a relative distance from the Kansas River have 87Sr/86Sr ratios, Sr contents and Sr/Ca ratios that are similar to those of the river water, suggesting a hydraulic connection between these aquifers and the river, as well as a lack of any impact of the vegetation. An underground water supply from nearby Summer Hill located to the north of the study area has also been detected, except for its western border where no interactions occurred apparently between the aquifer waters and the reservoir rocks, or with the creek and river waters. The 87Sr/86Sr signatures of the ground waters suggest also a major east-west flow system in the study area that can be divided into three entities, together with a supplementary north-south trend along the Threemile creek towards the Kansas River.