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K.V. Wilson

Publications and source records attributed to K.V. Wilson.

6 recordsLinked to original sources
USGS1995

Scour at selected bridge sites in Mississippi

Scour data were collected during 1936-94 at 22 bridge sites in Mississippi. The drainage area of the bridge-scour sites ranged from 60.8 to 5,720 square miles, and the slope in the vicinity of each site ranged from 0.00011 to 0.00163 foot per foot. Measured pier-scour depths ranged from 0.6 to 20.4 feet. Measured total-scour depths at minimum-bed elevation ranged from 5.2 to 29.8 feet. Recurrence intervals of measured streamflow discharges ranged from less than 2 years to about 500 years. All of the Mississippi pier-scour depths were within 2.3 times the normal pier width, which agreed with previous research. Only 12 (6 percent) of the 190 measured pier-scour depths were greater than 1.1 times the normal pier width. Measured pier-scour depths were as much as 2.24 times a normal pier width of 3.3 feet. However, for pier widths greater than about 4 feet, measured pier-scour depths were significantly less than 2.3 times the normal pier width. An envelope-curve equation for the Mississippi pier-scour data was developed by relating pier-scour depth divided by normal pier width to measured approach-flow depth divided by normal pier width. The envelope-curve equation predictions could be used for reasonable verifi- cations of the HEC-18 pier-scour predictions, currently required for the design and mainte- nance of bridges over waterways in Mississippi.

Water-Resources Investigations Report↗
USGS1994

Geomorphic response to channel modifications of Skuna River at the State Highway 9 crossing at Bruce, Calhoun County, Mississippi

Skuna River at State Highway 9 at Bruce, Calhoun County, Mississippi, has geomorphically responded to channel modifications by lowering of the channel bed through degradation, which heightened and steepened channel banks and induced widening. Skuna River Canal (Skuna River) has typically degraded about 16.5 feet and widened about 150 feet from 1925 (when constructed) to 1992. Old Skuna River has degraded and widened about 11 feet and 40 feet, respectively, from 1921 to 1991. Skuna River Canal tributary has degraded about 6 feet from 1921 to 1991. Most of the geomorphic response on the Old River and the tributary seems to be a consequence of modifications of the canal. The bankfull discharge of the canal has increased about 1,450 percent, and the channel slope has decreased about 34 percent from 1925 to 1989. The bankfull stream power has been decreasing since 1980. The bankfull channel width-depth ratio has been increasing since 1975, which indicates the canal has been widening more than degrading since 1975. As much as 1 foot of additional degradation and 40 feet of additional widening are projected through 2010 on Skuna River Canal in the vicinity of State Highway 9. About 70 feet of additional widening could occur before the canal reaches quasi-equilibrium, which will likely be reached after 2010. If Old Skuna River and Skuna River Canal tributary degrade as much as the canal, which is doubtful, then about 6 and 11 feet of additional degradation could occur by 2010 on the Old Skuna River and the tributary, respectively, at State Highway 9. Old Skuna River and the tributary could both widen an additional 30 feet in the next 10 to 20 years. The channel low-stage thalweg of Skuna River Canal is beginning to meander around sandbars inducing lateral erosion of the channel banks. The widening projections in this report do not directly account for lateral erosion and are considered to be a minimum for the typical channel reach. Lateral erosion will likely have a significant effect on future widening site.

Water-Resources Investigations Report↗
USGS1991

Flood characteristics of Mississippi streams

Flood magnitudes for selected recurrence intervals from 2 to 500 years were determined for 330 gaged sites in the study area where annual peak-flow records have been collected. The principal study area is Mississippi; however, selected data collected in adjoining States on streams draining into or from Mississippi are also included, flood frequency at a gaged stream site is defined by fitting the Pearson Type III probability distribution to the log-transformed annual peaks. The accuracy of the flood frequency determined for a gaged site is determined primarily by the number of years of annual peak-flow record (the sample size). Greater accuracy is achieved in the current analysis than in previous analyses because of the additional years of annual peak-flow record. Flood-frequency and basin characteristics at gaged sites were used to develop regression equations for estimating flood frequency where annual peak-flow records are not available. Flood frequency for ungaged stream sites in Mississippi may be estimated using basin characteristics in regression equations. Regression equations were computed using the generalized-least-squares procedure rather than the ordinary-least-squares procedure used in previous regional hydrologic analyses. The generalized-least-squares procedure considers the variable error of the gaging station flood frequencies and corrects for the cross-correlation of concurrent annual peaks. When the gaging stations in the sample for regression analysis have widely varying record lengths and concurrent peak flows, which are correlated between sites, the generalizedleast-squares procedure provides more accurate estimates of the regression coefficients and model error than does the ordinary-least-squares procedure. These flood-frequency equations provide managers with improved tools for estimating flood frequencies for purposes of management and design.

Mississippi↗