Authors: Bogumila Backiel*, University of Massachusetts - Amherst, Christian O Marks, The Nature Conservancy, Keith H Nislow, United States Forest Service
Topics: Environmental Science, Geomorphology, Remote Sensing
Keywords: sandbars, sediment, fluvial geomorphology, New England, dams, GIS, floodplains
Session Type: Paper
Start / End Time: 2:40 PM / 4:20 PM
Room: Studio 1, Marriott, 2nd Floor
Presentation File: No File Uploaded
The formation of new sandbars and islands in river channels by sediment deposition is the process by which topographically diverse floodplain habitats are created. Human development particularly dams and channelization, have altered flow and sediment regimes thereby impairing formation of sandbars. These geomorphic features are early successional habitats that are colonized by pioneer plant species like the sandbar willow (Salix exigua), sandbar cherry (Prunus pumila var depressa) and eastern cottonwood (Populus deltoides). Populations of many pioneer plant species are declining, including floodplain pioneer species. Endangered animal species like the wood turtle (Glyptemys insculpta) and the puritan tiger beetle (Cicindela puritana) depend on river bars for habitat. Large scale mapping of sediment deposition in rivers helps improve our understanding of the dynamics of these ecosystems, and is necessary to preserve not only these ephemeral floodplain habitats themselves but more importantly also the processes that create them. An automated object based image classification model was created in ArcGIS Pro, that uses 1 meter resolution aerial images from the National Agriculture Imagery Program (NAIP). The model was successfully applied to the entire Connecticut River and several of its major tributaries and mapped the active geomorpholic features. The results allow policy makers and conservation practitioners to identify locations in the watershed of active fluvial geomorphology. This spatial model will also provide researchers and conservation planners with a methodology for geomorphological mapping that can be applied in other large river ecosystems across the region.