Altitude isotope effects in Mediterranean high-relief terrains: a correction method to utilize stream water data
Altitude isotope effects in Mediterranean high-relief terrains: a correction method to utilize stream water data
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DOI：
10.1080/02626667.2021.1928672
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发表时间：
2021-05
影响因子：
3.5
通讯作者：
H. Hemmerle;R. van Geldern;T. Juhlke;F. Huneau;É. Garel;S. Santoni;J. Barth
中科院分区：
文献类型：
--
作者：
H. Hemmerle;R. van Geldern;T. Juhlke;F. Huneau;É. Garel;S. Santoni;J. Barth
降水同位素海拔效应的量化有助于确定高起伏地区的补给高度。然而，陡峭的地形往往限制了这种基于降水的方法的使用。多年生河流通常为全年的水采样提供方便。然而，在高凸起地区，河流可能不能充分代表区域降水同位素模式，因为它们在其过程中整合了同位素信号。这就阻止了仅从河流水样中计算海拔同位素梯度。我们提出了一项研究，显示了基于河流的采样方法如何用于确定海拔效应。用数字高程模型计算出的上游流域平均高程代替原始样地高度，使我们能够从溪水中建立一个可信的高度同位素效应。利用降水同位素资料对修正方法进行了独立验证。这种方法可以潜在地转移到其他难以确定不同海拔降水采样的地区。
ABSTRACT Quantification of the isotope altitude effect from precipitation allows the identification of recharge altitudes in high-relief areas. However, steep terrains frequently limit the use of this precipitation-based approach. Perennial rivers often provide easy, year-round access for water sampling. However, in high-relief regions rivers may not adequately represent regional precipitation isotope patterns because they integrate isotope signals along their course. This prevents the calculation of an altitudinal isotope gradient from river water samples alone. We present a study that shows how a river-based sampling approach served to determine the altitude effect. Replacing the original sample site altitude with the mean upstream catchment elevation as calculated from a digital elevation model allowed us to establish a plausible altitude isotope effect from stream water. The correction approach was verified independently using precipitation isotope data. This approach can potentially be transferred to other regions where precipitation sampling at various elevations is difficult to determine.