A thorough data analysis combined with groundwater modelling was conducted in an Austrian binary karst aquifer to better understand changes in the hydrological behaviour observed at a karst spring. During a period of 4 years after a major flood event the spring hydrograph appears to be more damped with lower peak flow and higher baseflow than in the years before. The analysis of the hydrograph recession suggests that the observed hydrological change is caused by changes within the karst system rather than by varying hydro-meteorological conditions. The functioning of the aquifer and potential causes of the observed changes are further examined using the groundwater flow model MODFLOW. The simulation results suggest that a modification of hydraulic conductivity and storage within the conduit network, e.g. due to the plugging of the drainage conduits with sediments, may be the cause of the different behaviour. MODFLOW was able to reproduce the observed dynamics of spring flow, although it does not account for turbulent flow within karst conduits. Using a simplified model scenario it is demonstrated that the damping of the hydrograph is much stronger if turbulent conduit flow is taken into account. Thus, a turbulent flow model is needed to assess potential changes in the storage properties quantitatively.

中文翻译：

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了解岩溶含水层内水文行为的变化（Lurbach 系统，奥地利）

在奥地利二元岩溶含水层中进行了结合地下水建模的彻底数据分析，以更好地了解在岩溶泉观察到的水文行为的变化。在大洪水事件发生后的 4 年期间，春季水位过程线似乎比前几年受到更大的阻尼，峰值流量更低，基流更高。对水文过程线衰退的分析表明，观察到的水文变化是由岩溶系统内部的变化引起的，而不是由水文气象条件的变化引起的。使用地下水流模型 MODFLOW 进一步检查含水层的功能和观察到的变化的潜在原因。模拟结果表明，管道网络内的水力传导率和存储的修改，例如 由于排水管道被沉积物堵塞，可能是导致不同行为的原因。MODFLOW 能够重现观察到的弹簧流动动力学，尽管它没有考虑岩溶管道内的湍流。使用简化的模型场景表明，如果考虑湍流管道流动，则水文过程线的阻尼要强得多。因此，需要一个湍流模型来定量评估存储特性的潜在变化。使用简化的模型场景表明，如果考虑湍流管道流动，则水文过程线的阻尼要强得多。因此，需要一个湍流模型来定量评估存储特性的潜在变化。使用简化的模型场景表明，如果考虑湍流管道流动，水文过程线的阻尼会更强。因此，需要一个湍流模型来定量评估存储特性的潜在变化。