Climate change and glacial retreat are changing the runoff behavior of Alpine springs and streams. For example, in the extremely dry and hot summer of 2018, many springs used for drinking water supply lost up to 50 percent of their average discharge; a few springs have even run dry. In order to ensure drinking water supply in the future, springs featuring large and constantly sufficient discharge rates will have to be identified and tapped. A case study was undertaken at the Tuxbachquelle because catchment area and temporal variation of physicochemical and hydrochemical properties were previously unknown. Tracer tests with uranine proved a hydraulic connection between this karst spring and a stream a few kilometers uphill. At low runoff, uranine needed about 4½ hours from the sink to the spring, whereas at high runoff more than four days was required. It became evident that discharge, electrical conductivity, temperature, and turbidity of the Tuxbachquelle respond within a few hours to precipitation events. The water quality and an examination of the water balance resulted in a significantly larger catchment area. It is assumed that widely karstified calcite marble subterraneously drains a considerable part of the Tuxertal (Tux Valley), including some active rock glaciers.

中文翻译：

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气候变化时期的供水——用于确定奥地利蒂罗尔高山岩溶泉集水区的示踪剂测试

气候变化和冰川退缩正在改变高山泉水和溪流的径流行为。例如，在2018年极端干燥炎热的夏季，许多用于饮用水供应的泉水损失了平均排放量的50%；一些泉水甚至干涸了。为了确保未来的饮用水供应，必须识别和挖掘具有大量且持续充足的排放量的泉水。在 Tuxbachquelle 进行了一项案例研究，因为以前未知流域面积和物理化学和水化学特性的时间变化。用铀进行的示踪剂测试证明了这个岩溶泉与几公里上坡的溪流之间存在液压连接。在低径流时，铀从汇到泉需要大约 4.5 小时，而在高径流时需要四天以上。很明显，Tuxbachquelle 的放电、电导率、温度和浊度会在几小时内对降水事件做出响应。水质和水平衡检查导致集水区面积明显扩大。据推测，广泛岩溶的方解石大理岩在地下排出了 Tuxertal（Tux Valley）的大部分地区，包括一些活动的岩石冰川。