Informing Restoration Practice Through Estimation of Groundwater-Surface Water Time Lags With Windowed Cross-Correlation
University of California, Merced
Video Not Available
California’s floodplain ecosystems and their riparian wetlands provide habitat for wildlife and essential ecosystem services such as water quality regulation and flood protection, but have seen major declines due to land use changes and development of water management infrastructure. Resource managers are increasingly recognizing the benefit of restoring floodplains for the multiple benefits they provide. For example, floodplain restoration provides opportunities for aquifer recharge, a strategy that can boost flexibility in water management portfolios in terms of ameliorating water scarcity challenges due to drought, groundwater overdraft, and projected climate-driven precipitation shifts from snow to rain. Planning of multi-benefit floodplain restoration projects will need tools to support project siting and understanding of groundwater-surface water interactions while informing the regulation of stream flow regimes. Our research addresses this need through the application of standard time-series analysis of groundwater and surface water data in the lower San Joaquin River in the California Central Valley. Windowed-cross correlations were applied to times series data to estimate time lags between stage and groundwater levels, providing insight to the strength of these flow connections. This method allows for quick assessment of groundwater-surface water interactions that can be a preliminary step in developing monitoring action to help identify suitable floodplain restoration sites.