Water Resources Research Act Program

Details for Project ID 2019ND210B

Interdisciplinary approach to understanding fluvial geomorphology of post-glaciolacustrine meandering rivers: a case study of the Red River

Institute: North Dakota
Year Established: 2019 Start Date: 2019-06-01 End Date: 2020-05-31
Total Federal Funds: $3,504 Total Non-Federal Funds: $7,008

Principal Investigators: Stephanie S. Day

Abstract: The Red River of the North is a post-glaciolacustrine fluvial landscape impacted by Glacial Isostatic Adjustments (GIAs) that have influenced the spatiotemporal pattern of erosion and valley development on the Red River. Modern GIA is complex in the area of the Red River, with a combination of forebulge collapse and rebound acting to decrease Red River valley-slope by 4.1 x 10-6 vertical meters per horizontal kilometer per year. Such impacts cause erosional instabilities in some reaches of the Red River and cause floods to span greater widths and last longer. Although floods cause the greatest planform changes in meandering channels, the fluvial geomorphology is likely significantly influenced by the floodplain alluvium, hydrology, and GIA. The proposed research will apply (a) GIS mapping and analysis methods to determine the current erosional state of the Red River, (b) combined laboratory and numerical Landscape Evolution Modeling to constrain the dates of major channel avulsions of Red River Basin rivers, and (c) conduct field sampling of alluvial sediments to determine both the process of short term erosion during the spring thaw and the possible control of alluvium grain size distribution and composition on channel planform and meandering dynamics. Understanding the fluvial geomorphology of the Red River is important for the inhabitants of the land because of the persistent threat of floods, and because it is unique among rivers due to its excessively low slope, high sinuosity, geological infancy, and its rare existence atop a massive former lake bottom.