Insights into hydrologic and hydrochemical processes based on concentration‐discharge and end‐member mixing analyses in the mid‐Merced River Basin, Sierra Nevada, California
Insights into hydrologic and hydrochemical processes based on concentration‐discharge and end‐member mixing analyses in the mid‐Merced River Basin, Sierra Nevada, California
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DOI：
10.1002/2016wr019437
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发表时间：
2017-01
影响因子：
5.4
通讯作者：
Fengjing Liu;M. Conklin;G. Shaw
中科院分区：
文献类型：
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作者：
Fengjing Liu;M. Conklin;G. Shaw
利用2006-2008年在快乐岛（468 km 2）、波霍诺桥（833 km 2）和布里塞堡收集的化学数据，对浓度-流量关系和端元混合分析进行了探索，以阐明水文和水化学过程的连通性（1873平方公里）在融雪喂养的中默塞德河流域，由美国地质调查局在1990-2014年期间在快乐岛收集的化学数据增强。水流中的浓度-流量（C-Q）由明确的幂律关系控制，指数的大小（0.02-0.6）和R2值（p < 0.001）在上升分支上低于下降分支。水流中保守溶质的浓度是由快乐岛和波霍诺桥的两个端元和布里塞堡的三个端元混合而成的，端元中的溶质浓度相对恒定。在所有流域尺度上，地下水的贡献率都是上升段高于下降段。由于端元混合的结果，地下水流和地下水与径流（F-Q）的部分贡献之间的关系遵循与C-Q相同的关系。F-Q关系被用作一个简单的模型来模拟从1990年到2014年快乐群岛的地下水流和地下水排放，并通过USGS测量的溶质浓度成功验证。研究还表明，F-Q和C-Q关系的一致性适用于端元和C-Q关系定义明确的其他流域，表明水文和水化学过程是强耦合和相互可预测的。结合浓度-流量和端元混合分析，可用作诊断工具，以了解流域水文研究中的径流生成和水化学控制。
Both concentration‐discharge relation and end‐member mixing analysis were explored to elucidate the connectivity of hydrologic and hydrochemical processes using chemical data collected during 2006–2008 at Happy Isles (468 km2), Pohono Bridge (833 km2), and Briceburg (1873 km2) in the snowmelt‐fed mid‐Merced River basin, augmented by chemical data collected by the USGS during 1990–2014 at Happy Isles. Concentration‐discharge (C‐Q) in streamflow was dominated by a well‐defined power law relation, with the magnitude of exponent (0.02–0.6) and R2 values (p < 0.001) lower on rising than falling limbs. Concentrations of conservative solutes in streamflow resulted from mixing of two end‐members at Happy Isles and Pohono Bridge and three at Briceburg, with relatively constant solute concentrations in end‐members. The fractional contribution of groundwater was higher on rising than falling limbs at all basin scales. The relationship between the fractional contributions of subsurface flow and groundwater and streamflow (F‐Q) followed the same relation as C‐Q as a result of end‐member mixing. The F‐Q relation was used as a simple model to simulate subsurface flow and groundwater discharges to Happy Isles from 1990 to 2014 and was successfully validated by solute concentrations measured by the USGS. It was also demonstrated that the consistency of F‐Q and C‐Q relations is applicable to other catchments where end‐members and the C‐Q relationships are well defined, suggesting hydrologic and hydrochemical processes are strongly coupled and mutually predictable. Combining concentration‐discharge and end‐member mixing analyses could be used as a diagnostic tool to understand streamflow generation and hydrochemical controls in catchment hydrologic studies.