Naturalization of the Flood Regime in Regulated Rivers: The Case of the Upper211 Mississippi River. Long Term Resource Monitoring Program

摘要

In this article, the authors assess the degree of change in the flow regimes of211u001ethe Illinois and upper Mississippi rivers and describe ongoing efforts to restore 211u001eor naturalize the regimes. The authors begin by describing the natural pattern of 211u001ewater level variation and its importance, both to organisms and ecosystem 211u001eprocesses, prior to large-scale human alteration. Next, the authors explain how 211u001enavigation dams, drainage of uplands and floodplains, and changes in 211u001eprecipitation patterns have altered the flood regimes. The authors next describe 211u001eseveral contrasting perspectives regarding threats to the two rivers and discuss 211u001ethe feasibility of naturalizing or restoring water and sediment regimes. Finally, 211u001ethe authors assess several approaches to flow naturalization, including 211u001econtrolled flooding and dewatering in leveed compartments on the floodplain, and 211u001ealtered dam operations on the mainstem river. These approaches are applicable to 211u001eother rivers with navigation dams and leveed floodplains.