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Temperature dynamics of a proglacial stream: Identifying dominant energy balance components and inferring spatially integrated hydraulic geometry
Author(s) -
Magnusson Jan,
Jonas Tobias,
Kirchner James W.
Publication year - 2012
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/2011wr011378
Subject(s) - streams , environmental science , inflow , hydrology (agriculture) , riparian zone , glacier , stream bed , groundwater , streamflow , channel (broadcasting) , surface runoff , hyporheic zone , geology , geomorphology , sediment , drainage basin , geotechnical engineering , ecology , computer network , oceanography , cartography , engineering , habitat , computer science , geography , electrical engineering , biology
Proglacial fields typically have complex topography and heterogeneous sediments, resulting in highly variable flow and temperature regimes in surface runoff and groundwater. Using data from the Damma glacier forefield (Switzerland), we examined how longitudinal stream temperature changes can be used to infer reach‐averaged hydrological and thermal processes in proglacial riparian zones. A simple energy balance showed that (1) radiative forcing and frictional warming largely explained the observed temperature patterns in three stream reaches, and that (2) groundwater inflow and/or hyporheic exchange appear to influence stream warming along a fourth reach. Daytime stream warming depends on channel width, and here we show that stream temperature measurements can be used to infer reach‐averaged hydraulic geometry relationships between stream width and discharge, which are normally difficult to obtain by other methods in braided gravel bed streams. Our results illustrate how proglacial stream temperatures can yield spatially integrated information about hydrological and thermal processes in glacial forefields, where extreme spatial heterogeneity makes conventional methods difficult to apply.