fluvial geomorphology + design Form and Flow Flow is generally considered the primary variable driving process in the river ecosystem. Through the periodic flow variation, the renewal of riparian vegetation communities can occur, fish spawning habitats emerge, and the transport of nutrients can be shared between the river and floodplain. With an engineered river system such as the Missouri River, periodic flows are less realistic than in an unchannelized river system. However, the hydrograph, which is the defintion of the change in flow of a particular river system, can be restored somewhat to mimic a healthy river system by allowing for more water to be released at a higher rate from the reservoirs in the spring months, for instance. If flow is restored, it can help with the timing of floods, water tempearture and turbidity.
Fall
Approx. 24,000 cfs
Winter
Approx. 16,000 cfs
Summer
Approx. 37,000 cfs
The hydrological characteristics of a river channel include magnitude, frequency, duration, timing and rate of change. These characteristics determine how much water is in the channel and for how long. The hydrological characteristics of the Missouri River have been affected by the addition of revetments along its banks. Revetments like wing dikes cause the thalweg of the river, or main channel, to self-dredge. This has caused the Missouri River to incise 3-5 meters as far as 100 km downstream from its dams. Predicting stream flows and depth is not an analytical science. There are no known processes for determining exactly how a river will change over time. There are only parameters that can be followed to corral river waters into its designated flood plain. When designing for river systems, research has pointed to a staging method with multiple tiers the river can somewhat adhere to. Benefits of the staging method include the establishment of vegetation, decreased erosion rates because the river is allowed to spread horizontally instead of being vertically constricted. During a drought condition, the lowest channel can still provide sufficient water depth for fish. Floods can be pushed out into the upper tier or flood plain and prevent constriction and release of flood waters on to developed areas near the river.
Early Spring
Approx. 20,000 cfs
Late Spring
Approx. 32,000 cfs
Flood Condtions Approx. 60,000 cfs+