Groundwater and surface water flow to the Merced River, Yosemite Valley, California: ³⁶Cl and Cl⁻ evidence

Abstract

Our current understanding of water fluxes and flow paths within the mountain block is limited, and improved understanding is necessary to assess hydrology more accurately above the mountain front. Source waters and the processes controlling their mixing were characterized in the Merced River basin within Yosemite National Park, California, using 36

Temporal dynamics in dominant runoff sources and flow paths in the Andean Páramo

“…In accordance with our results, the essential role of shallow groundwater in headwater catchments was reported by Shaw et al . [] in California and high mountain catchments in Scotland with similar hydropedological conditions [ Blumstock et al ., ]. In addition to our primary results regarding the relevance of shallow groundwater, detailed studies of its spatiotemporal variability are still required to better understand its contribution to runoff generation [ Lana‐Renault et al ., ; Rinderer et al ., ].…”

Insights into hydrologic and hydrochemical processes based on concentration‐discharge and end‐member mixing analyses in the mid‐Merced River Basin, Sierra Nevada, California

“…A previous study using 36 Cl and Cl − by Shaw et al . [] found that streamflow in the Merced River within Yosemite National Park was dominated by three source water end‐members: (1) near‐surface runoff of recent melt water containing bomb‐pulse 36 Cl, (2) shallow groundwater with low Cl − concentrations, and (3) deep groundwater containing high Cl − concentrations derived through extended rock interaction. Surface runoff directly generated from snowmelt (i.e., overland flow) was not a dominant end‐member.…”

“…Particularly in snowmelt‐dominated catchments, many studies have demonstrated significant difference in isotopic and solute concentrations in snowmelt runoff, shallow subsurface flow, and groundwater and significant temporal variations of isotopic and chemical concentrations in streamflow [e.g., Li et al ., ; Blaen et al ., ; Liu et al ., ]. As a result, end‐member mixing analysis, based on a single, paired or multiple tracers, has been successfully applied to identify and quantify source waters (end‐members) contributing to streamflow [e.g., Engel et al ., ; Miller et al ., ; Frisbee et al ., ; Shaw et al ., ; Liu et al ., ]. Results of end‐member mixing analysis help understand flow paths, residence times and sources of streamflow [e.g., Tetzlaff et al ., ].…”

Spatial organization of groundwater dynamics and streamflow response from different hydropedological units in a montane catchment

“…Montane catchments are usually characterized by thin soils and dynamic GW stores in drift or bedrock with poor aquifer properties (Soulsby et al, 2000;Aishlin and McNamara, 2011). Shallow GW flow paths usually dominate in smaller headwater catchments, whilst deeper GW sources become more important as catchment size increases (Shaw et al, 2014). Whilst some studies have pointed to the importance of fractures and faults in different types of rock formations as important conduits for mountain GW movement (Katsuyama et al, 2008;Haria et al, 2013;Caulfield et al, 2014), in many glaciated regions, superficial drift deposits often provide larger sources of GW (Soulsby et al, 1998;Detty and McGuire, 2010).…”