Extensive research has been conducted on the effects of anthropogenic practices on lowland rivers and floodplains; particularly regarding planform changes, only a few studies have utilized detailed riverbed elevation data.
This study focuses on the Apalachicola River, one of the largest lowland rivers in the southeastern United States. The navigation project by the United States Army Corps of Engineers, which began in the late 1950s and continued till 2002, significantly impacted the Apalachicola River. The dredging and disposal, artificial cutoffs, and snag removal carried out as part of the navigation efforts significantly altered the Apalachicola River.
Using bathymetric survey data from 1960 to 2010, we developed a high-resolution digital elevation model (DEM) to analyze geomorphic changes in the lower Apalachicola River and conduct a DEM of differences analysis for the 50-year period. We assessed the river’s net sediment gain and loss patterns using the DEMs and geostatistical approaches. We quantified the cumulative sediment volume change and gross change (cumulative absolute change) per river mile of the lower Apalachicola River between 1960 and 2010.
The study revealed that the entire reach (RM ~ 45-0) experienced a loss of 8.36 million m3, a gain of 6.99 million m3, a gross change of 15.35 million m3, and a net change of 1.37 million m3. The reach upstream of the juncture with the Lower Chipola (~ RM 28), where several artificial cutoffs were present, experienced a net loss of 4.52 million m3.
In this reach and just downstream of the juncture between RM 30 and 27, multiple pools deepened markedly. These morphological alterations have significantly compromised natural river–floodplain connectivity and altered critical aquatic habitats, particularly affecting the spawning and nursery areas essential for the region’s diverse freshwater mussel populations and other endemic species.
However, downstream of RM 28, the Apalachicola had a net gain of 3.14 million m3, probably associated with sediment supply from downcutting and lateral erosion occurring upstream.
This comprehensive sediment budget analysis provides essential quantitative evidence for river managers and restoration practitioners, demonstrating that navigation-induced modifications can redistribute over 15 million m3 of sediment across a 45-mile reach, with direct implications for habitat restoration planning, flood risk assessment, and sustainable waterway management in similar modified lowland river systems globally.
Alruzuq, A. R., Mossa, J., Amanambu, A. C., Chen, Y. H., & Brenner, M. (2025). Morphodynamics and riverbed elevation changes in the lower Apalachicola River: a study of large lowland river systems. Acta Geophysica, 74(1), 11.
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