TY - JOUR
T1 - Seasonal and Interannual Patterns and Controls of Hydrological Fluxes in an Amazon Floodplain Lake With a Surface-Subsurface Process Model
AU - Ji, Xinye
AU - Lesack, Lance F.W.
AU - Melack, John M.
AU - Wang, Shilong
AU - Riley, William J.
AU - Shen, Chaopeng
N1 - Funding Information:
This research was supported by Office of Biological and Environmental Research of the U.S. Department of Energy under contract DE-SC0010620. Shen was partially supported by U.S. Department of Energy under contract DE-SC0016605. Additional support for J. M. M. during the manuscript preparation was provided by NASA grant NNX17AK49G. The preprocessed data used in this work, including observations of lake stage, climate forcing, river-lake exchanges, and runoff estimated in LM95, can be accessed in the supporting information of this paper. The river stage and daily precipitation were obtained from ANA, Brazilian National Water Agency. The CRUNCEP forcing data were obtained from Viovy (). The lake stage, river-lake exchange, and runoff estimates were obtained from Lesack's PhD thesis.
Funding Information:
This research was supported by Office of Biological and Environmental Research of the U.S. Department of Energy under contract DE‐SC0010620. Shen was partially supported by U.S. Department of Energy under contract DE‐SC0016605. Additional support for J. M. M. during the manuscript preparation was provided by NASA grant NNX17AK49G. The preprocessed data used in this work, including observations of lake stage, climate forcing, river‐lake exchanges, and runoff estimated in LM95, can be accessed in the supporting information of this paper. The river stage and daily precipitation were obtained from ANA, Brazilian National Water Agency. The CRUNCEP forcing data were obtained from Viovy (2018). The lake stage, river‐ lake exchange, and runoff estimates were obtained from Lesack's PhD thesis.
Publisher Copyright:
©2019. American Geophysical Union. All Rights Reserved.
PY - 2019/4
Y1 - 2019/4
N2 - Floodplain lakes represent important aquatic ecosystems, and field-based estimates of their water budgets are difficult to obtain, especially over multiple years. We examine the hydrological fluxes for an Amazon floodplain lake connected to the Solimões River using a process-based hydrologic model. Water exchanges between the river and lake agree well with field estimates, including the timing of different hydrological phases. However, beyond available field data, modeling results show that the seven simulated years all differed from each other. These interannual differences were caused by the interplay between phases when water levels were rising with river-water flowing into the lake (RWRI), versus rising with lake-water flowing out to the river (RWLO). This exchange determines the river-water content in the lake (CL). Maximum CL occurred before river levels peaked because local catchment contributions can be sufficient to push lake-water out to the river, even as river levels rise. Numerical experiments show that the seasonal distribution of local rainfall, local catchment size, and interannual variability in both climate and river stage can contribute to differing dynamics of CL in a floodplain lake. Their impacts vary among phases: river-rise dominates the RWRI, whereas local hydrological processes dominate the RWLO and receding-water phases. Intermediate-to-long-term rainfall accumulation controls CL during the RWLO phase, whereas annual precipitation accumulation is important for CL during low water. Our model generalizes beyond limited available field studies and offers potential to better understand floodplain lakes in other areas and how regional versus local changes in climate may affect their hydrological dynamics.
AB - Floodplain lakes represent important aquatic ecosystems, and field-based estimates of their water budgets are difficult to obtain, especially over multiple years. We examine the hydrological fluxes for an Amazon floodplain lake connected to the Solimões River using a process-based hydrologic model. Water exchanges between the river and lake agree well with field estimates, including the timing of different hydrological phases. However, beyond available field data, modeling results show that the seven simulated years all differed from each other. These interannual differences were caused by the interplay between phases when water levels were rising with river-water flowing into the lake (RWRI), versus rising with lake-water flowing out to the river (RWLO). This exchange determines the river-water content in the lake (CL). Maximum CL occurred before river levels peaked because local catchment contributions can be sufficient to push lake-water out to the river, even as river levels rise. Numerical experiments show that the seasonal distribution of local rainfall, local catchment size, and interannual variability in both climate and river stage can contribute to differing dynamics of CL in a floodplain lake. Their impacts vary among phases: river-rise dominates the RWRI, whereas local hydrological processes dominate the RWLO and receding-water phases. Intermediate-to-long-term rainfall accumulation controls CL during the RWLO phase, whereas annual precipitation accumulation is important for CL during low water. Our model generalizes beyond limited available field studies and offers potential to better understand floodplain lakes in other areas and how regional versus local changes in climate may affect their hydrological dynamics.
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U2 - 10.1029/2018WR023897
DO - 10.1029/2018WR023897
M3 - Article
AN - SCOPUS:85064517516
VL - 55
SP - 3056
EP - 3075
JO - Water Resources Research
JF - Water Resources Research
SN - 0043-1397
IS - 4
ER -