Reliable estimates of the dynamic volume of karst aquifers, i.e. the drainable volume of groundwater, are important in the context of sustainable management and environmental protection of the karst water resources. Extrapolation of the observed recession of spring hydrographs is commonly used as a basis for the estimation of the dynamic volume. However, our understanding concerning the reliability of this approach is still limited. Therefore, the adequacy of this approach is investigated using flow models of hypothetical karst aquifers to assess the deviation of the extrapolated from the real recession curve and identify parameters controlling the extrapolated recession coefficient. The results show that parameters such as the geometry of the catchment area and point recharge have little effect on the accuracy of the estimated dynamic volume. Low extension of the highly conductive zone and increase in specific yield or catchment area with depth of the aquifer result in the underestimation of the dynamic volume. Groundwater abstraction and decrease of specific yield or catchment area with increasing saturated thickness can lead to an overestimation of the dynamic volume. These findings clarify the potential underestimation or overestimation in dynamic volume estimates on the basis of the observed recession characteristics.

岩溶含水层动态体积的可靠估算，即地下水的可排水体积，对于岩溶水资源的可持续管理和环境保护具有重要意义。观察到的弹簧水位线衰退的外推通常用作估计动态体积的基础。然而，我们对这种方法的可靠性的理解仍然有限。因此，使用假设的岩溶含水层的流动模型来评估这种方法的充分性，以评估外推与实际衰退曲线的偏差，并确定控制外推衰退系数的参数。结果表明，集水区的几何形状和点补给等参数对估算动态体积的准确性影响不大。高导水带的低扩展和随着含水层深度的增加而增加的比产量或集水面积导致低估动态体积。随着饱和厚度的增加，地下水的抽取和特定产量或集水面积的减少会导致对动态体积的高估。根据观察到的衰退特征，这些发现阐明了动态交易量估计中潜在的低估或高估。