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Geology topics

Joseph H. Wlosinski

Publications and source records attributed to Joseph H. Wlosinski.

3 recordsLinked to original sources

Analysis of water level management on the upper Mississippi River (1980–1990)

Management at 27 low-head dams affects water surface elevations for a 1050km stretch of the Upper Mississippi River (UMR) between St Louis, Missouri and Minneapolis, Minnesota. A systemic overview is given of current operating plans at dams on the UMR and historical data are analysed to determine how well the operating plans are being met. Water level elevations at all 27 dams are regulated as a function of discharge, although plans are specific for each dam. The management objective is to maintain a target water level at specific locations (control point) in each impoundment over specific ranges of discharge. The target water level and control point may change as discharge changes in each impoundment. In some of the impoundments water regulation causes drawdowns below the elevation for which the dams were planned, and at other dams no drawdown occurs. During the navigation seasons of 1980 to 1990, water levels were within their target window for an average of 72·5% of the time for 25 dams analysed. Difficulties in meeting targets are caused by winds, local rainfall events, ice dams and rapidly fluctuating discharges from tributaries with upstream reservoirs used for peaking hydropower.

Upper Mississippi River

Pool 13 drawdown: Predicting success rates and affected areas

The likelihood of 1- or 2-foot drawdowns, and the area affected by such alternative drawdowns, was estimated for Pool 13 on the Upper Mississippi River. Minimum water surface (elevation) requirements were compared to computed water surface profiles to determine a critical low flow that would allow a navigation channel 400 feet wide and 10.5 feet deep. An upper limit on flow was established based on the flow at which open river conditions would exist for a given drawdown. The range in flows that would allow for a drawdown was used to estimate success rates using historical daily discharge data. Success rates were determined for a variety of drawdown durations between two time periods. May 1—August 15 and June 15—August 15. The greatest effect of the drawdown would he near Lock and Dam 13. Higher discharges, as well as distance from the dam. lessen the drawdown amount. Areas that would he affected by these two drawdown scenarios were predicted by overlaying maps of water surfaces with depths using a geographic information system. Although the drawdown effects on most physical and biotic components of Pool 13 arc unknown, some general drawdown effects likely to occur because of the changes in water surface elevation are presented.

Illinois, Iowa

A macrophyte submodel for aquatic ecosystems

A macrophyte submodel has been incorporated and tested in CE-QUAL-R1, a one-dimensional, vertically averaged model of reservoir water quality. A quasi two-dimensional scheme was necessary to represent the spatial relationship of macrophytes in reservoirs adequately. The macrophyte processes modeled were photosynthesis, dark respiration, excretion and nonpredatory mortality. Process equations for photosynthesis as a function of light and temperature, and dark respiration as a function of temperature were tested using data from laboratory studies. The submodel was field tested, along with other components of CE-QUAL-R1, using data collected at Eau Galle Reservoir, WI, U.S.A.

Wisconsin