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Seasonal variation in surface‐subsurface water exchange and lateral hyporheic area of two stream‐aquifer systems
Author(s) -
Wroblicky Gregory J.,
Campana Michael E.,
Valett H. Maurice,
Dahm Clifford N.
Publication year - 1998
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 - 10.1029/97wr03285
Subject(s) - hyporheic zone , hydrology (agriculture) , streams , groundwater , aquifer , geology , alluvium , groundwater recharge , bedrock , groundwater flow , hydraulic conductivity , geomorphology , soil science , geotechnical engineering , soil water , computer network , computer science
We used two‐dimensional unconfined transient groundwater flow models to investigate the interface between stream and groundwater flow systems, or hyporheic zone, of two first‐order streams that drain catchments with distinctly different alluvial sediments and bedrock lithology. Particle tracking showed that lateral hyporheic area (planimetric area of flow paths lateral to the stream that are recharged by and return to the stream with travel times of 10 days or less) differed between the two study streams and varied with discharge within each system. At the Rio Calaveras (welded tuff), lateral hyporheic area ranged from 1.7 to 4 m 2 over the annual cycle. In the Aspen Creek system (sandstone), lateral hyporheic area (1–1.5 m 2 ) was restricted to roughly half of that observed at Rio Calaveras. The size of the hyporheic zone lateral to the streams at both sites decreased by approximately 50% during high flows. Sensitivity analyses indicated that changes in the hydraulic conductivity of alluvial and streambed sediments and variation in recharge rates have greatest impact on the magnitude, direction, and spatial distribution of stream‐groundwater exchange.