TY - JOUR
T1 - Simulation of baseflow accounting for the effect of bank storage and its implication in baseflow separation
AU - Chen, Xi
AU - Chen, David Yongqin
AU - Chen, Xun hong
N1 - Funding Information:
This research was partially supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. CUHK4247/03H). It was also partially supported by a grant from the Program for New Century Excellent Talents in University, China (NCET-04-0492) and a US Geological Survey grant to the University of Nebraska-Lincoln. Joe Szilagyi provided technique review and Charlie Flowerday provided editorial review.
PY - 2006/8/20
Y1 - 2006/8/20
N2 - Most baseflow separation methods for measured streamflow discharge series are based on linear and non-linear solutions of the Dupuit-Boussinesq stream-aquifer model and do not take diverse geological, hydrological, and morphological factors into account. Therefore, a key issue in baseflow separation and drought flow estimation is to reveal baseflow variations related to these factors. This study analyzed the baseflow generated from the return of bank storage to the stream using a numerical groundwater model. Under different stream-aquifer hydrologic conditions in terms of river flood-wave shapes, hydraulic conductivities, stream-aquifer interconnection, recharge and evapotranspiration, and regional hydraulic gradients, baseflow was simulated in order to investigate the non-linearity in the baseflow recession process and to evaluate the baseflow separation methods for drought flow analysis. A comparison between flood recession derived from the Boussinesq equation and that from numerical models indicated that a linear aquifer system does not hold for bank storage effects. Analyses of numerically simulated baseflow discharge also demonstrate that values of power indices of the widely used storage-discharge functions which are derived from the single-valued power law are not constant but depend on hydraulic conductivities, stream-aquifer interconnection, and other surface hydrologic conditions. Bank storage due to the stream flood-stage fluctuation reduces groundwater discharge into the channel considerably in the flood stage rising period. Thus, neglecting the influence of bank storage on baseflow would result in a large error in baseflow separation for non-ideal stream-aquifer systems.
AB - Most baseflow separation methods for measured streamflow discharge series are based on linear and non-linear solutions of the Dupuit-Boussinesq stream-aquifer model and do not take diverse geological, hydrological, and morphological factors into account. Therefore, a key issue in baseflow separation and drought flow estimation is to reveal baseflow variations related to these factors. This study analyzed the baseflow generated from the return of bank storage to the stream using a numerical groundwater model. Under different stream-aquifer hydrologic conditions in terms of river flood-wave shapes, hydraulic conductivities, stream-aquifer interconnection, recharge and evapotranspiration, and regional hydraulic gradients, baseflow was simulated in order to investigate the non-linearity in the baseflow recession process and to evaluate the baseflow separation methods for drought flow analysis. A comparison between flood recession derived from the Boussinesq equation and that from numerical models indicated that a linear aquifer system does not hold for bank storage effects. Analyses of numerically simulated baseflow discharge also demonstrate that values of power indices of the widely used storage-discharge functions which are derived from the single-valued power law are not constant but depend on hydraulic conductivities, stream-aquifer interconnection, and other surface hydrologic conditions. Bank storage due to the stream flood-stage fluctuation reduces groundwater discharge into the channel considerably in the flood stage rising period. Thus, neglecting the influence of bank storage on baseflow would result in a large error in baseflow separation for non-ideal stream-aquifer systems.
KW - Bank storage
KW - Baseflow
KW - Flood stage
KW - Groundwater flow model
KW - Stream-aquifer system
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U2 - 10.1016/j.jhydrol.2005.11.057
DO - 10.1016/j.jhydrol.2005.11.057
M3 - Article
AN - SCOPUS:33746266277
SN - 0022-1694
VL - 327
SP - 539
EP - 549
JO - Journal of Hydrology
JF - Journal of Hydrology
IS - 3-4
ER -