The world´s waterways will be the focus of an international gathering of scientists, engineers, resource managers, and humanities researchers at the International Conference on Rivers and Civilization in LaCrosse, Wis. June 25-28. All presentations are in the LaCrosse Center. A world of earth-science information will be available at the USGS exhibit booth.
Monday, June 26
Engineering the Mississippi: An Introductory Overview
The Mississippi and its tributaries are among the most intensively engineered of the largest rivers of the world. Since the early 1700s, settlers have used increasingly sophisticated methods to control the river. Flood-control levees have been constructed for nearly three centuries. During the middle 1800s, the first intensive phase of river engineering for navigation began. Channel-constricting dikes and wing dams were built to narrow the flow and to direct scouring currents toward the deepening of the channel. Dam construction began a century ago and continued through the 20th Century. Bank-stabilization works have been steadily added to channel the flow and to retard erosion of the banks. The author will discuss the history of engineering along the Mississippi and its tributaries, and describe the consequences that include the stabilization of the main channels and a significant decrease in sediment delivered to the coastal wetlands along the Gulf of Mexico.
Fish Tales of the Past, Present, and Future of the Upper Mississippi River Ecosystem
The Upper Mississippi River has been extensively modified to enhance navigation, minimize flood damage, and generate electrical power. Because major modifications preceded the understanding of the river´s ecology, the consequences of those modifications can only be inferred. Although dams have restricted the ranges of some fishes and commercial navigation has had some adverse effects, fish biodiversity has remained stable, and species that were likely abundant prior to modification are still abundant today. The important question is not "What has been lost?" but rather "How can ecological services, including fish production, be preserved and even enhanced as the navigation capacity of the Upper Mississippi is expanded?"
Re-engineering the Missouri River: Integrating Sound Science into River Rehabilitation
The 2340 mile long Missouri River that Lewis and Clark observed in 1804 was highly braided with numerous sandbars and islands, shifting channels, high turbidity, and flooded frequently. Today, the middle one third is impounded behind six reservoirs, and the lower one third is flow-regulated. Eleven fishes are imperiled and the least tern, piping plover, and pallid sturgeon are endangered. The author will discuss a series of events since 1986 that have catalyzed rehabilitation of the Missouri River
Conservation of Upper Mississippi River Floodplain Forests: Threats and Action
Losses of floodplain forests of the Upper Mississippi River System as a result of flow management for commercial navigation and floodplain development have been dramatic system-wide. Hydrological changes continue to decrease species diversity and habitat structure, and invasive reed canary grass further threatens forest sustainability. Such changes are likely to have undesirable impacts on wildlife, ecosystem functions, and aesthetics of the river. The author will discuss the current evidence that causes concern about the sustainability of these forests, describe their value to wildlife, and examine coordinated research and management focused on restoring and maintaining floodplain forest health
An Evaluation of a Structural Method Versus a Non-Structural Method Applied to Restore Aquatic Vegetation in Pool 8 of the Upper Mississippi River
Pool 8 of the Upper Mississippi River near La Crosse has been a test ground of two different methods for restoring aquatic vegetation: building earthen structures that created habitats for vegetation, and a non-structural method to create summer low water level episodes similar to the natural flow regime that was lost after the river was impounded for navigation in 1938. The author will present the results of sampling since 1998 to quantify the effects of each of the two restoration methods.
Wednesday, June 28
GIS for the Gulf: A Geographic Reference Database for Hurricane Affected Areas (see also P-25)
GIS for the Gulf is a Geographic Information System database to locate natural and man-made physical features for areas of Louisiana, Alabama, Mississippi and Texas that were affected by Hurricanes Katrina and Rita. USGS and contractors have collected data sets in14 themes and hundreds of sub-themes including transportation, boundaries, hydrography, and elevation to assist in recovery and assist decision makers in rebuilding the Gulf.
Posters, South Hall A:
Monday, June 26, 5:30-7:30 p.m.
Nitrogen Cycling in Sediment during Water Level Drawdown on the Upper Mississippi River
Water level reductions, or "draw downs," are being used more frequently in large rivers to improve vegetation growth and wildlife habitat. The authors selected two areas of the Upper Mississippi River system: Navigation Pool 8 and Swan Lake, Ill. to examine whether water level drawdown is an effective means of reducing already high nitrogen concentrations in the Upper Mississippi.
GIS for the Gulf: A Geographic Reference Database for Hurricane Affected Areas
See O-047 Oral Session 34 for description.
Management and Recovery of Fish Species-At-Risk in the Upper Missouri River Basin: A Basin-Wide Approach
In North America about 34 percent of an estimated 1061 freshwater fish species are declining and in need of protection. To direct conservation efforts, decision support tools are needed. Gap analysis is an innovative decision support tool that uses biological data, remote sensing, and geographic information systems technology to predict species distributions, habitat, and locations where conservation programs can best protect species at risk. The author will describe a gap analysis of the Upper Missouri River Basin that included 26 major drainages and six eco-regions in portions of six states and two Canadian provinces to identify high priority areas.
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