Classification of reaches in the Missouri and lower Yellowstone Rivers based on flow characteristics

Abstract

Several aspects of flow have been shown to be important determinants of biological community structure and function in streams, yet direct application of this approach to large rivers has been limited. Using a multivariate approach, we grouped flow gauges into hydrologically similar units in the Missouri and lower Yellowstone Rivers and developed a model based on flow variability parameters that could be used to test hypotheses about the role of flow in determining aquatic community structure. This model could also be used for future comparisons as the hydrological regime changes. A suite of hydrological parameters for the recent, post-impoundment period (1 October 1966-30 September 1996 for each of 15 gauges along the Missouri and lower Yellowstone Rivers were initially used. Preliminary graphical exploration identified five variables for use in further multivariate analyses. Six hydrologically distinct units composed of gauges exhibiting similar flow characteristics were then identified using cluster analysis. Discriminant analyses identified the three most influential variables as flow per unit drainage area, coefficient of variation of mean annual flow, and flow constancy. One surprising result was the relative similarity of flow regimes between the two uppermost and three lowermost gauges, despite large differences in magnitude of flow and separation by roughly 3000 km. Our results synthesize, simplify and interpret the complex changes in flow occurring along the Missouri and lower Yellowstone Rivers, and provide an objective grouping for future tests of how these changes may affect biological communities. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted. ABSTRACTSeveral aspects of flow have been shown to be important determinants of biological community structure and function in streams, yet direct application of this approach to large rivers has been limited. Using a multivariate approach, we grouped flow gauges into hydrologically similar units in the Missouri and lower Yellowstone Rivers and developed a model based on flow variability parameters that could be used to test hypotheses about the role of flow in determining aquatic community structure. This model could also be used for future comparisons as the hydrological regime changes. A suite of hydrological parameters for the recent, post-impoundment period (1 October 1966-30 September 1996 for each of 15 gauges along the Missouri and lower Yellowstone Rivers were initially used. Preliminary graphical exploration identified five variables for use in further multivariate analyses. Six hydrologically distinct units composed of gauges exhibiting similar flow characteristics were then identified using cluster analysis. Discriminant analyses identified the three most influential variables as flow per unit drainage area, coefficient of variation of mean annual flow, and flow constancy. One surprising result was the relative ...

Hydrological alteration along the Missouri River Basin: A time series approach

“…This carryover can lead to sustained higher flows and can temporally influence water release schedules beyond individual, annual climatic conditions. There is evidence to support this idea as post-impoundment period gauges that are heavily influenced by dam operations have exhibited annual variability that does not coincide with flow variability in other reaches of the Missouri River (Pegg and Pierce, 2002).…”

“…The Omaha, NE, gauge also experienced slightly lower spring fish spawning flows, indicating that the river is still influenced by reservoir operations roughly 250 km downstream of the last impoundment. However, moving downstream from these impoundments appears to mediate flow differences between the two periods due to inputs from relatively large tributaries (Galat and Lipkin, 2000;Pegg and Pierce, 2002). These tributaries are also regulated but to a lesser extent and not necessarily synchronous with Missouri River operations, thus providing additional variability.…”

Flathead catfishPylodictis olivarisdiet composition during extreme flow events in a large river

“…The largest tributary in this reach is the Platte River, which has been identified as a major contributor to discharge and sediment transport regimes in the Missouri River downstream of the Platte confluence (Pegg & Pierce 2002). Three sampling sites were located upstream and two sites were located at or downstream of the Platte River confluence (Figure 1).…”

De biologische kwaliteit van waterlopen, kanaal en vijvers in het Brussels Hoofdstedelijk Gewest in 2016.

“…Deze methode is echter niet praktisch vooral bij sterke stroming. Voor grote rivieren (> 30 m breed) worden vaak verschillende technieken gecombineerd (Meffe & Berra, 1988;Pegg & Pierce, 2002) of alleen sleepnetten gebruikt (Angermeier & Smogor, 1994). Immers bij dieptes van meer dan 2 m wordt het moeilijk om met elektriciteit te vissen (De Leeuw et al, 2007 …”