| The groundwater and surface water comprise a single source of water resources. Efficient and sustainable water resource management requires using groundwater and surface water conjunctively. Worldwide, many water shortage problems come from the fact that neither the timing nor the location of precipitation coincide with water demands. Climate change makes this problem even worse. For California particularly, the warming trend is shifting more precipitation to fall as rain rather than snow during winter season, thereby reducing snow pack in Sierra Nevada Mountains. In addition, snowmelt is occurring earlier in spring due to warmer temperatures, therefore reducing the availability of snowmelt water that contributes to stream flow and surface reservoirs during dry summer season. Climate projections also suggest that winter floods will become more frequent, as will hotter and drier summers. The imbalance in time of water distribution within a year (wet, dry season), and between years (wet, dry year), as well as extreme climate events (for example, 1997 California flood, 2012-2014 California mega drought), create great challenges for water resource management. It is especially true when climate change effect is expected to continue.;This study evaluates winter floodplain inundation as a strategy of capturing and storing excess winter flood water beneath Central Valley floor to restore groundwater for local subsurface reservoir development. The parallel, variably saturated flow modeling code, ParFlow, is chosen to model the spatial and temporal patterns of surface water and groundwater interaction in heterogeneous subsurface under floodplain inundation at lower Cosumnes River floodplain. Particularly, the mechanics of groundwater and surface interaction in heterogeneous subsurface is investigated. Capturing and storing excess winter flood water for the development of local subsurface groundwater reservoir and its impact on water resource management is discussed..;Results of this study show that groundwater and surface water interaction under floodplain inundation is controlled by the heterogeneity of subsurface, primarily the connectivity of heterogeneity, as well as flood water inundating dynamics. A local subsurface reservoir can be augmented through floodplain inundation practice. However, its role of mitigating climate change impact on water resource management on a long time frame needs further investigation. |
