Simulation of Missouri River Bed Degradation

Hydrodynamic and morphodynamic response to river engineering documented by fixed-discharge analysis, Lower Missouri River, USA

“…National Research Council, 2002). The second major hydrologic effect of the dams was caused by sediment trapping, which reduced loads at the dam outlets 'essentially to zero' (MRRRCC, 1998) and caused severe erosion downstream including incision of up to 2.4 m (Rahn, 1977;Holly and Karim, 1986). Sediment starvation in the system also affected channelization practices, requiring the abandonment of the earlier use of timber pile dikes in favor of stone wing dams.…”

Factors affecting the reproduction, recruitment, habitat, and population dynamics of pallid sturgeon and shovelnose sturgeon in the Missouri River

“…Operation of Gavins Point Dam has caused changes in the aquatic habitat (Schmulbach and others, 1981;. Turbidity and temperature have decreased: the timing, duration, and extent of spring flows have diminished: channel incision has increased: channel macrohabitats have been dewatered: and substrate size on the river bottom has increased from scouring (Holly and Karin, 1986). Habi-tat change and fish stocking caused shifts in the kinds and numbers of plankton, macroinvertebrates, and fishes after the dam was closed (Morris and others 1968;Walburg and others, 1971;Committee on Missouri River Ecosystem Science, 2002).…”

Recurrent shoaling and channel dredging, Middle and Upper Mississippi River, USA

“…Predam sediment loads averaged 135 million tons/year at Gavins Point, the site of the most downstream of the Missouri River dams, but these loads were reduced essentially to zero following dam closure (US Army Corps of Engineers, Missouri River Region Reservoir Control Center, 1998). Sediment starvation following dam construction triggered severe downcutting of the Missouri River channel downstream (Holly and Karim, 1986), although the river has been reacquiring some of its load through incision and bank erosion (Rahn, 1977). The Illinois River lacks the large floodcontrol reservoirs of the Missouri, but the eight locks and lock-and-dam structures along the Illinois render it tame and navigable along its entire 536 km course (Bhowmik et al, 1988).…”