Variability and controls of riverbank erosion in the United States from 35 years of satellite imagery.
Abstract
Riverbank migration has historically been seen as a risk to buildings and infrastructure, and it has often been combatted through channelization, bank stabilization, and flow regulation. More recently, these actions are seen as impractical to maintain and destructive to riparian ecology. Our current understanding of riverbank erosion and migration is a synthesis of reach-scale studies and large-scale models. We expand on this work by developing and evaluating a new dataset of riverbank erosion using optical imagery from Landsat 5, 7, and 8, starting in 1984. Because this data is primarily based on optical satellite imagery, we cannot estimate changes below the water surface, and we therefore focus on changes in river planform at mean discharge. We limit errors caused by changes in river stage by incorporating discharge data from more than 5,000 USGS gages to estimate periods of mean flow. Additionally, we plan to evaluate our estimates of erosion and accretion rates by comparing with previous studies and in situ measurements. As a first attempt at understanding the human influence on bank erosion at the scale of the United States, we will compare the downstream effects of 343 large dams. Preliminary results on the Missouri River, downstream of the Fort Peck Dam, showed a long-term imbalance of erosion and accretion which extends 150 km below the dam.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMEP0120028L
- Keywords:
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- 1815 Erosion;
- HYDROLOGY;
- 1824 Geomorphology: general;
- HYDROLOGY;
- 1825 Geomorphology: fluvial;
- HYDROLOGY;
- 1826 Geomorphology: hillslope;
- HYDROLOGY