Final Report: Science to Inform the Reconnection of Floodplains and Restoration of Green Space to Minimize Risk in the Future
Citation
Richard Palmer and Keith Nislow, 2019, Reconnecting Floodplains and Restoring Green Space as a Management Strategy to
Minimize Risk and Increase Resilience in the Context of Climate and Landscape Change.
Summary
The “Reconnecting Floodplains and Restoring Green Space as a Management Strategy to Minimize Risk and Increase Resilience in the Context of Climate and Landscape Change” project explores green infrastructure opportunities to manage flows, connections, and watersheds in order to improve both flood protection and ecosystem services. This project’s research specifically investigates how restoring floodplains would impact human welfare and environmental conservation. Its research objectives are addressed in two parts: 1) developing a hydraulic model to illustrate how changes in floodplain management may impact flooding along the Connecticut River, and 2) developing a geo-spatial model that demonstrates the distribution and abundance of [...]
Summary
The “Reconnecting Floodplains and Restoring Green Space as a Management Strategy to Minimize Risk and Increase Resilience in the Context of Climate and Landscape Change” project explores green infrastructure opportunities to manage flows, connections, and watersheds in order to improve both flood protection and ecosystem services. This project’s research specifically investigates how restoring floodplains would impact human welfare and environmental conservation. Its research objectives are addressed in two parts: 1) developing a hydraulic model to illustrate how changes in floodplain management may impact flooding along the Connecticut River, and 2) developing a geo-spatial model that demonstrates the distribution and abundance of sandbars along the Connecticut River and its tributaries.
Floodplains retain water, an ecosystem service that naturally mitigates flood impacts on human communities living along major rivers. The hydraulic model developed for this project analyzes the flooding impacts of eight scenarios that vary in their ratio of land-use (forested land to field land) within a floodplain. Study findings suggest that as floodplain restoration efforts increase, flood peaks decrease downstream and habitat suitability improves. Restoration leads to reduced flood risk for downstream inhabitants, however, the number of impacted people residing directly in the upstream floodplain can increase. Flood flow duration can also increase expanding the available suitable land for restoration focused efforts. Alternatively, as development in the upstream floodplain grows, flood events increase flood risk for downstream inhabitants, while habitat suitability diminishes and the impact to floodplain residents decreases. Sandbars and islands in lowland rivers form when sediment (silt, sand, and gravel) is deposited in places where the stream velocity decreases.
Sandbars and islands are the preceding habitats that evolve into floodplains. Their distribution and abundance provide information about sediment transport and flow in 2 a river, both of which influence flood risk to neighboring human communities. This study develops a spatial model to track changes in these habitats in the Connecticut River watershed, allowing for the comparison of their distribution and abundance currently and around times of storms and extreme flooding. The developed tool is effective in quantifying critical river habitat and identifying key river and floodplain areas for conservation at large scales. Sandbars are an appropriate ecological metric that this model can map to inform conservation decisions that affect floodplain restoration.
