A two‐component hydrograph separation for three high‐elevation catchments in the Sierra Nevada, California
A two‐component hydrograph separation for three high‐elevation catchments in the Sierra Nevada, California
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DOI：
10.1002/hyp.1414
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发表时间：
2004-06
影响因子：
3.2
通讯作者：
A. Huth;A. Leydecker;J. Sickman;R. Bales
中科院分区：
文献类型：
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作者：
A. Huth;A. Leydecker;J. Sickman;R. Bales
在红杉国家公园，对三个嵌套的融雪主导集水区进行了双分量过程线分离。过程线分离的目的是：（i）使用δ 18 O特征区分融雪期间排放的新旧水贡献;（ii）使用二氧化硅或钠确定融雪期间通过地下（反应）隔间的融雪部分;（iii）调查变化的端元特征对分离的影响。“旧”水是指前一年储存在流域的水，而“新”水是当前的融雪。对高累积（1998年，年降水量2.4 m）和平均年（1999年，1.3 m）进行了水文分离。在过程线上升段，老水对流量的贡献比例为10- 20%，80-100%的融雪是反应性的，即通过土壤和堆积物。1999年，各集水区对新老土壤水和直接进入河流的融雪水的估计各不相同。在1998年，这些组成部分之间的差异是最小的，无论不同的地形和不同比例的土壤，岩石和岩屑。使用时间依赖性而不是恒定的δ 18 O融水和硅土水特征对新的和旧的水，以及反应性和非反应性的估计产生了有意义的影响。版权所有© 2004年约翰威利父子有限公司。
Two‐component hydrograph separations were performed for three, nested, snowmelt‐dominated catchments in Sequoia National Park. The purpose of the hydrograph separations was to: (i) differentiate between the old and new water contributions to discharge during snowmelt using δ18O signatures; (ii) identify the fraction of snowmelt that travelled through the subsurface (reactive) compartment during the snowmelt period using silica or sodium; and (iii) investigate the impact of changing end‐member signatures on the separations. ‘Old’ water refers to water that was stored in the watershed during the previous year, whereas ‘new’ water is current snowmelt. Hydrograph separations were performed for both a high‐accumulation (1998, annual precipitation 2·4 m) and an average year (1999, 1·3 m). The proportion of old water contribution to discharge during the rising limb of the hydrograph was 10–20%, with 80–100% of snowmelt being reactive, i.e. passing through soil and talus. Estimates of old and new soil water and direct snowmelt entering the stream varied among the catchments in 1999. Differences between these components were minimal in 1998, regardless of varying topography and differing proportions of soil, rock and talus. Using time‐dependent rather than constant δ18O meltwater and silica soil‐water signatures made a meaningful impact on both new and old water, and reactive and unreactive, estimates. Copyright © 2004 John Wiley & Sons, Ltd.