Upper Mississippi River Restoration Program Long Term Resource Monitoring

Recent Planform Changes in the Upper Mississippi River

Rogala, J. T., F. A. Fitzpatrick, and J. S. Hendrickson.  2020. Recent Planform Changes in the Upper Mississippi River.  A completion report submitted to the U.S. Army Corps of Engineers’ Upper Mississippi River Restoration Program from the U.S. Geological Survey, LTRM-2019GC8. 33 pp. with appendixes.

Abstract

The Upper Mississippi River Restoration program’s Landcover Use (LCU) data from each of the 1989, 2000, and 2010/2011 imagery were developed using similar methods and are available in a Geographical Information System (GIS) for the entire UMR and therefore provide the opportunity for a more comprehensive planform change analysis. This study used GIS overlays of LCU classes to map and quantify changes in planform features over two periods, looking specifically for depositional areas where terrestrial and wetland vegetation expanded at the expense of open water. The land expansion was grouped into four possible process-based types common in large floodplain rivers, some following that used by Lewin et al. (2017). The four types include: crevasse deltas emanating from a breach from a main channel through a natural levee or narrow floodplain into backwaters (crevasse deltas), tributary deltas expanding into backwaters (tributary deltas), deltaic bars at the upstream end of impoundments (impounded deltas), and linear-like bars extending from the downstream ends of narrow levees and remnant floodplains (bar-tail limbs). The methods deployed for change detection addressed possible errors from a variety of sources.