Effects of a regional channel stabilization project on suspended sediment yield

• Published in: Journal of soil and water conservation Vol. 63; no. 2; pp. 59 - 69
• Main Author: Shields, F.D. Jr
• Format: Journal Article
• Language: English
• Published: Ankeny, IA Soil and Water Conservation Society 01.03.2008; Soil & Water Conservation Society
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Conservation Effects Assessment Project (CEAP); Data analysis; Environmental aspects; Erosion control; Fundamental and applied biological sciences. Psychology; governmental programs and projects; Sediment control; Sediment transport; sediment yield; Soil erosion control; Soil erosion, conservation, land management and development; Soil science; soil stabilization; Streamflow; streams; Trends; water erosion; watershed hydrology; Watershed management; Watersheds; Mississippi; United States; North America; America; Conservation Effects Assessment Project (CEAP)-channel incision-erosion control-sediment concentration-sediment yield-watershed; Subtropical zone; Suspended particle; Project; sediment yield; Stabilization; Canal; Watershed; Erosion control; Resource management; Sediments; Soil conservation
• ISSN: 0022-4561; 1941-3300; 1941-3300
• DOI: 10.2489/jswc.63.2.59

Under legislation passed in 1984, three federal agencies constructed more than $300 million worth of channel erosion control measures in 16 watersheds in northern Mississippi between 1985 and 2003. Most work was completed between 1985 and 1995 and was confined to six larger watersheds. Flows of water and suspended sediment emanating from these watersheds were measured from 1986 until 1997 and for longer periods for two of these gages and one additional gage. Statistical analyses of flow-adjusted instantaneous measured concentration data failed to detect significant trends at six of the seven gages. A downward trend was noted for a watershed in which eight reservoirs were constructed. These results indicate that watershed-level effects of even large-scale erosion control measures are difficult to detect over 5 to 15 years. Evidently substantial reductions in sediment yields require changes in watershed hydrology that reduce runoff and peak flows or changes in channel bed slope.