Premium
Groundwater similarity across a watershed derived from time‐warped and flow‐corrected time series
Author(s) -
Rinderer M.,
McGlynn B. L.,
van Meerveld H. J.
Publication year - 2017
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 - 10.1002/2016wr019856
Subject(s) - groundwater , hydrology (agriculture) , surface runoff , environmental science , topographic wetness index , similarity (geometry) , streams , streamflow , watershed , groundwater flow , drainage basin , scale (ratio) , geography , geology , remote sensing , ecology , digital elevation model , cartography , computer science , aquifer , computer network , geotechnical engineering , artificial intelligence , machine learning , image (mathematics) , biology
Information about catchment‐scale groundwater dynamics is necessary to understand how catchments store and release water and why water quantity and quality varies in streams. However, groundwater level monitoring is often restricted to a limited number of sites. Knowledge of the factors that determine similarity between monitoring sites can be used to predict catchment‐scale groundwater storage and connectivity of different runoff source areas. We used distance‐based and correlation‐based similarity measures to quantify the spatial and temporal differences in shallow groundwater similarity for 51 monitoring sites in a Swiss prealpine catchment. The 41 months long time series were preprocessed using Dynamic Time‐Warping and a Flow‐corrected Time Transformation to account for small timing differences and bias toward low‐flow periods. The mean distance‐based groundwater similarity was correlated to topographic indices, such as upslope contributing area, topographic wetness index, and local slope. Correlation‐based similarity was less related to landscape position but instead revealed differences between seasons. Analysis of variance and partial Mantel tests showed that landscape position, represented by the topographic wetness index, explained 52% of the variability in mean distance‐based groundwater similarity, while spatial distance, represented by the Euclidean distance, explained only 5%. The variability in distance‐based similarity and correlation‐based similarity between groundwater and streamflow time series was significantly larger for midslope locations than for other landscape positions. This suggests that groundwater dynamics at these midslope sites, which are important to understand runoff source areas and hydrological connectivity at the catchment scale, are most difficult to predict.