Journal article
Sedimentology of a delta formed by agricultural river discharge into a flood-control reservoir, Iowa
River research and applications, Vol.40(8), pp.1584-1594
10/01/2024
DOI: 10.1002/rra.4326
Appears in UI Libraries Support Open Access
Abstract
River deltas are ecologically critical landscape components and are responsible as habitats for millions of people, wildlife, and plant communities. Deltas store vast quantities of eroded nutrient-rich sediment and play a significant role in water quality management through nutrient cycling and storage. Many studies have been conducted in marine and tidal delta environments that characterize the sedimentology and geomorphic characteristics of these relatively young landscapes. However, little work has been completed in even younger inland reservoir deltas. This study characterized the sediments and geomorphology of the growing delta forming at the outlet of the Des Moines River into Red Rock Reservoir in south-central Iowa and discussed the implications of the lower delta sediment and topographic characteristics in terms of sediment and nutrient storage, and the potential impact of the delta on other hydroecological factors. We found that the ca. 30-year-old lower delta is storing up to 60% of the contributing watershed's eroded sediment and total carbon, with total sediment depths of ca. 9 m across the 755-ha area. Further, we identified two major geomorphic landscape positions within the lower delta that were categorized as distributary channels and delta plains. Sedimentological differences in these microscale landscape positions were identified. Sand content was greater at lowest distributary channel elevations and at the highest plain elevations whereas silt dominated the elevation range between these two extremes. The zone of silt accumulation corresponds to the range in elevation associated with normal lake level management. The silt-dominated area is regularly inundated and covered with a variety of emergent vegetation and is the zone of critical importance for waterbird habitat and nutrient-processing capacity.
Details
- Title: Subtitle
- Sedimentology of a delta formed by agricultural river discharge into a flood-control reservoir, Iowa
- Creators
- Matthew T. Streeter - United States Geological SurveyKeith E. Schilling - University of IowaThomas Stoeffler - University of Iowa, IIHR--Hydroscience and EngineeringElliot Anderson - University of Iowa
- Resource Type
- Journal article
- Publication Details
- River research and applications, Vol.40(8), pp.1584-1594
- Publisher
- Wiley
- DOI
- 10.1002/rra.4326
- ISSN
- 1535-1459
- eISSN
- 1535-1467
- Number of pages
- 11
- Grant note
- U.S. Army Corps of Engineers; United States Department of Defense; United States Army US Army Corps of Engineers; United States Department of Defense; United States Army
- Language
- English
- Electronic publication date
- 05/23/2024
- Date published
- 10/01/2024
- Academic Unit
- Earth and Environmental Sciences; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984633160302771
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