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Temporal Scaling of Groundwater Level Fluctuations Near a Stream
Author(s) -
Schilling Keith E.,
Zhang YouKuan
Publication year - 2011
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.2011.00804.x
Subject(s) - groundwater recharge , groundwater , riparian zone , hydrology (agriculture) , floodplain , scaling , environmental science , geology , channel (broadcasting) , streams , soil science , geomorphology , aquifer , geography , geometry , ecology , geotechnical engineering , mathematics , cartography , electrical engineering , engineering , habitat , computer science , biology , computer network
Temporal scaling in stream discharge and hydraulic heads in riparian wells was evaluated to determine the feasibility of using spectral analysis to identify potential surface and groundwater interaction. In floodplains where groundwater levels respond rapidly to precipitation recharge, potential interaction is established if the hydraulic head ( h ) spectrum of riparian groundwater has a power spectral density similar to stream discharge ( Q ), exhibiting a characteristic breakpoint between high and low frequencies. At a field site in Walnut Creek watershed in central Iowa, spectral analysis of h in wells located 1 m from the channel edge showed a breakpoint in scaling very similar to the spectrum of Q (∼20 h), whereas h in wells located 20 and 40 m from the channel showed temporal scaling from 1 to 10,000 h without a well‐defined breakpoint. The spectral exponent ( β ) in the riparian zone decreased systematically from the channel into the floodplain as groundwater levels were increasingly dominated by white noise groundwater recharge. The scaling pattern of hydraulic head was not affected by land cover type, although the number of analyses was limited and site conditions were variable among sites. Spectral analysis would not replace quantitative tracer or modeling studies, but the method may provide a simple means of confirming potential interaction at some sites.