Journal article
From agricultural intensification to conservation; sediment transport in the Raccoon River, Iowa, 1916-2009
Journal of environmental quality, Vol.40(6), pp.1911-1923
11/2011
DOI: 10.2134/jeq2010.0507
PMID: 22031575
Abstract
Fluvial sediment is a ubiquitous pollutant that negatively affects surface water quality and municipal water supply treatment. As part of its routine water supply monitoring, the Des Moines Water Works (DMWW) has been measuring turbidity daily in the Raccoon River since 1916. For this study, we calibrated daily turbidity readings to modern total suspended solid (TSS) concentrations to develop an estimation of daily sediment concentrations in the river from 1916 to 2009. Our objectives were to evaluate long-term TSS patterns and trends, and relate these to changes in climate, land use and agricultural practices that occurred during the 93-yr monitoring period. Results showed that while TSS concentrations and estimated sediment loads varied greatly from year to year, TSS concentrations were much greater in the early 20th century despite drier conditions and less discharge, and declined throughout the century. Against a backdrop of increasing discharge in the Raccoon River and widespread agricultural adaptations by farmers, sediment loads increased and peaked in the early 1970s, and then have slowly declined or remained steady throughout the 1980s to present. With annual sediment load concentrated during extreme events in the spring and early summer, continued sediment reductions in the Raccoon River watershed should be focused on conservation practices to reduce rainfall impacts and sediment mobilization. Overall, results from this study suggest that efforts to reduce sediment load from the watershed appear to be working.
Details
- Title: Subtitle
- From agricultural intensification to conservation; sediment transport in the Raccoon River, Iowa, 1916-2009
- Creators
- Christopher S. Jones - Iowa Soybean AssociationKeith E. Schilling - Iowa Geological and Water Survey109 Trowbridge HallIowa CityIA52242-1319
- Resource Type
- Journal article
- Publication Details
- Journal of environmental quality, Vol.40(6), pp.1911-1923
- Publisher
- American Society of Agronomy, [and] Crop Science Society of America, [and] Soil Science Society of America
- DOI
- 10.2134/jeq2010.0507
- PMID
- 22031575
- ISSN
- 0047-2425
- eISSN
- 1537-2537
- Language
- English
- Date published
- 11/2011
- Academic Unit
- Earth and Environmental Sciences; IIHR--Hydroscience and Engineering
- Record Identifier
- 9984383906202771
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