GREAT I

GREAT I
Author: Great River Environmental Action Team (U.S.)
Publisher:
Total Pages: 380
Release: 1980
Genre: Dredges
ISBN:

Sediment Response to Large-scale Environmental Change

Sediment Response to Large-scale Environmental Change
Author: Richard P. R. Pannell
Publisher:
Total Pages: 150
Release: 1999
Genre:
ISBN:

Knowledge about sediment yields is important in developing management strategies for fluvial systems. The effect of sediment must be considered in the design of river structures and in determining water quality for biotic systems. Changes in sediment transport regimes are difficult to understand or predict due to the complexity of factors that influence sediment flux in fluvial systems. Relationships about sediment source, sinks and transport have long been studied and many of these relationships have been quantitatively and qualitatively defined. However, due to the scarcity of long-term sediment records it is often difficult to test these relationships. This study examines one of these long-term suspended sediment records for the Mississippi River at East Dubuque, Illinois from 1943 to 1996. Daily suspended sediment concentrations from the United States Army Corps of Engineers station at East Dubuque were analyzed for the spring and summer months (March - August). Sediment concentrations were analyzed in terms of average concentration during different hydrologic events at the large basin scale. These events included the spring snowmelt runoff (low and high magnitude) and different intensity storm runoff (low, moderate and high). Additionally, peak sediment concentrations during storm runoff were also analyzed. The general trend for all of these analyses suggests a significant decrease in sediment concentrations from the 1940s to the 1990s. The strongest trends are found in high magnitude snowmelt runoff and in high and moderate magnitude storm runoff. Peak concentrations in storm runoff have decreased from about 1000 ppm in the l940s to about 200 ppm in the 1990s. Average concentrations have likewise decreased from about 200 ppm in the 1940s to 100 ppm in the 1990s. Changes in land management practices are identified as being the primary environmental factor influencing sediment concentrations.

GREAT II

GREAT II
Author:
Publisher:
Total Pages: 140
Release: 1980
Genre: Conservation of natural resources
ISBN:

The 1993 Flood on the Mississippi River in Illinois

The 1993 Flood on the Mississippi River in Illinois
Author: Nani G. Bhowmik
Publisher:
Total Pages: 160
Release: 1994
Genre: Flood damage
ISBN:

The lessons learned from this flood focus on the performance of the levees, governmental responses, the effects of flood fighting, change in stages due to levee breaches, flood modeling, and the lack of information dissemination to the public on the technical aspects of the flood. These lessons point out information gaps and the need for research in the areas of hydraulics and hydrology, meteorology, sediment transport and sedimentation, surface and ground-water interactions, water quality, and levees. The report presents a comprehensive summary of the 1993 flood as far as climate, hydrology, and hydraulics are concerned.