Author(s): F. D. Shields Jr.; Scott S. Knight

Linked Author(s):

Keywords: No Keywords

Abstract: Lowland riverine ecosystems depend on the materials and habitats provided by floodplain backwaters, and studies of floodplain lakes indicate that connectivity with the adjacent river is a key determinant of lake fish species assemblages. Since about 1800, off-channel habitats have declined in quality and quantity due to modification and development of most of the world’s major rivers and their floodplains. Hydrologic connections between the river and backwaters become shorter and less frequent when river stages are lowered by incision or controlling elevations for floodplain water bodies are raised by sediment deposition. Proposals for rehabilitation and management of backwaters typically include restoring connection with the main channel by re-opening channels closed by sedimentation, water control structures to manipulate water levels, increasing inflow from groundwater, or diverting polluted runoff away from backwater inflow. Although large sums are spent annually on backwater rehabilitation, general design criteria for such projects are lacking.

DOI:

Year: 2009