Authors: Amena Begum Ruma*, University of South Dakota, Mark Dixon, University of South Dakota, Mark Sweeney, University of South Dakota , S M Asger Ali, Mississippi State University
Topics: Geomorphology, Geographic Information Science and Systems, Remote Sensing
Keywords: successional vegetation, set-aside sandbars, LiDAR, riparian, GIS
Session Type: Virtual Guided Poster
Start / End Time: 1:30 PM / 2:45 PM
Room: Virtual 53
Presentation File: No File Uploaded
Decades of flow regulation due to upstream dams reduced sandbar area and the recruitment of early successional forests of cottonwood and willow along the Missouri River in the northcentral US. Management conflicts exist between managing remaining sandbars for habitat (removing vegetation) for threatened sandbar-nesting birds (i.e., Piping Plover) and allowing natural recruitment of early successional riparian woodland (set-aside bars) that may support other species and ecological values. Recent changes in topography, geomorphology, and vegetation were examined on sandbars that have been “set aside” from management within seven reaches of the Missouri National Recreational River (MNRR) in southeastern South Dakota, USA. An existing time series of maps of sandbar habitat and vegetation, derived from satellite imagery, was analyzed using ArcGIS to track past vegetation dynamics and geomorphic changes from 2009-2016. Digital Elevation Models (DEMs) of the seven reaches were used to detect elevational changes on the bars from 2012-2016, the years following the flood. The time series maps revealed that sandbar area was highest in 2012 (just after the flood) and declined thereafter and the elevation change maps showed that most areas did not show significant changes from 2012-2016. The findings could help inform managers from the National Park Service and US Army Corps of Engineers about how the sandbars have evolved due to flood events. This information is critical for managing the bars in a way that will balance the needs of sandbar nesting birds and the multiple species of birds and other wildlife that use early successional riparian vegetation.