Hydrospatial Analysis of Inundation Patterns for a Restored Floodplain to Evaluate Potential Climate Change Impacts
Abstract
Interaction between rivers and their floodplains create dynamic physical conditions supporting freshwater ecosystems. The natural flood regimes to which native species are adapted are often profoundly altered by interacting factors including water management, land use change, and climate change. Reintroducing dynamic flood regimes through enhancing river-floodplain connectivity is a common floodplain restoration objective. However, it is often difficult to determine how various actions (or a combination of actions), such as levee setbacks or environmental flow releases, will impact physical conditions relevant to ecological functions, such as depth, velocity, duration, timing, and connectivity, and how these might change in the future. Understanding changes to these dynamic conditions requires improved quantification of spatiotemporal variability of floodplain inundation patterns, in essence a floodplain's hydrospatial regime. The research presented here develops this concept by quantifying the hydrospatial regime of a floodplain along the lower Cosumnes River, California, both before and after levee-removal restoration, and uses this to evaluate how effects of restoration may be altered with changing hydrology due to climate change. This approach uses spatial analysis in R to summarize metrics based on estimated spatially-distributed depth and velocity, derived from 2D hydrodynamic modeling output for pre- and post-restoration conditions. This is performed for an historical and two future periods of daily flow of the largely unregulated Cosumnes River, driven by a subset of global climate models. We show that responses to restoration vary across the hydrospatial domain and further consider these differences in floodplain dynamics in relation to hydroclimatic change. This research refines expectations for restoration and overall provides readily applied methods to inform planning and management of floodplain ecosystems within the context of climate change. Quantifying how changes due to restoration vary over space and time improves our ability to manage floodplains for variable conditions that benefit ecosystems.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.H51D1296W
- Keywords:
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- 1813 Eco-hydrology;
- HYDROLOGY;
- 1820 Floodplain dynamics;
- HYDROLOGY;
- 1830 Groundwater/surface water interaction;
- HYDROLOGY;
- 1852 Plant uptake;
- HYDROLOGY