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J.T. Wilson

Publications and source records attributed to J.T. Wilson.

27 records · Page 2Linked to original sources

Bathymetric surveys of Morse and Geist Reservoirs in central Indiana made with acoustic Doppler current profiler and global positioning system technology, 1996

Acoustic Doppler current profiler, global positioning system, and geographic information system technology were used to map the bathymetry of Morse and Geist Reservoirs, two artificial lakes used for public water supply in central Indiana. The project was a pilot study to evaluate the use of the technologies for bathymetric surveys. Bathymetric surveys were last conducted in 1978 on Morse Reservoir and in 1980 on Geist Reservoir; those surveys were done with conventional methods using networks of fathometer transects. The 1996 bathymetric surveys produced updated estimates of reservoir volumes that will serve as base-line data for future estimates of storage capacity and sedimentation rates.An acoustic Doppler current profiler and global positioning system receiver were used to collect water-depth and position data from April 1996 through October 1996. All water-depth and position data were imported to a geographic information system to create a data base. The geographic information system then was used to generate water-depth contour maps and to compute the volumes for each reservoir.The computed volume of Morse Reservoir was 22,820 acre-feet (7.44 billion gallons), with a surface area of 1,484 acres. The computed volume of Geist Reservoir was 19,280 acre-feet (6.29 billion gallons), with a surface area of 1,848 acres. The computed 1996 reservoir volumes are less than the design volumes and indicate that sedimentation has occurred in both reservoirs. Cross sections were constructed from the computer-generated surfaces for 1996 and compared to the fathometer profiles from the 1978 and 1980 surveys; analysis of these cross sections also indicates that some sedimentation has occurred in both reservoirs.The acoustic Doppler current profiler, global positioning system, and geographic information system technologies described in this report produced bathymetric maps and volume estimates more efficiently and with comparable or greater resolution than conventional bathymetry methods.

Water-Resources Investigations Report

Evaluation of scour at selected bridge sites in Indiana

Twenty bridge sites in Indiana were evaluated to determine: the extent of scour during floods, streambed stability, the maximum historical scour, and estimates of potential scour. Historical scour data were collected by means of geophysical methods and used to evaluate the scour-computation procedures recommended by the U.S. Federal Highway Administration and 13 other published pier-scour equations. Hydraulic conditions for the peak historical discharges were estimated by use of WSPRO, a water-surface profile computation model. Depth soundings were made periodically at all of the sites and during flooding at some sites. These data indicate that scour may not totally be a function of discharge or depth but is influenced greatly by debris on piers.

Indiana

Low-flow characteristics of Indiana streams

Knowledge of low-flow characteristics of streams is essential for management of water resources. Low-flow characteristics are presented for 229 continuous-record, streamflow-gaging stations and 285 partial-record stations in Indiana. Low- flow-frequency characteristics were computed for 210 continuous-record stations that had at least 10 years of record, and flow-duration curves were computed for all continuous-record stations. Low-flow-frequency and flow-duration analyses are based on available streamflow records through September 1993. Selected low-flow-frequency curves were computed for annual low flows and seasonal low flows. The four seasons are represented by the 3-month groups of March-May, June-August, September-November, and December- February. The 7-day, 10-year and the 7-day, 2 year low flows were estimated for 285 partial-record stations, which are ungaged sites where streamflow measurements were made at base flow. The same low-flow characteristics were estimated for 19 continuous-record stations where less than 10 years of record were available. Precipitation and geology directly influence the streams in Indiana. Streams in the northern, glaciated part of the State tend to have higher sustained base flows than those in the nonglaciated southern part. Flow at several of the continuous-record gaging stations is affected by some form of regulation or diversion. Low-flow characteristics for continuous-record stations at which flow is affected by regulation are determined using the period of record affected by regulation; natural flows prior to regulation are not used.

Indiana

Characteristics, transport, and yield of sediment in Juday Creek, St. Joseph County, Indiana, 1993-94

Juday Creek is a tributary of the St. Joseph River in St. Joseph County, north-central Indiana. The creek has been identified as one of the few streams in the State that can support a naturally reproducing brown trout population. A recent study of benthic invertebrates shows a decline in the production rate of insect species and suggests that this decline may be caused by increased sedimen- tation. This report presents the results of a study of the sediment conditions in Juday Creek from April 1993 through June 1994. Measurements of streamflow, suspended sediment, and bedload were made at six sampling sites during three storms and a period of low flow. A total of 11 samples were collected during storms, and 1 sample was collected during low flow at each site. Bed-material samples were collected at the six sites. Sediment cores were collected from the delta of an instream pond and at a sediment trap near the mouth of the stream. Scour and fill at the six sites were monitored by means of scour chains and surveyed cross sections. The instream pond was surveyed twice, and the volume weight of the sediment was determined to estimate the yield of sediment for the upper reach of Juday Creek. Particle-size distributions indicate that the bed material is predominantly sand and gravel and that very little of the bed material is silt or finer (less than 0.062 millimeter). Analysis of sediment cores showed that most of the sediment deposited in the sediment trap and instream pond was sand. Sediment sampling during a period of low flow detected only minimal concentrations of suspended sediment; the maximum concentration was 6 milligrams per liter, equivalent to a daily load of 0.32 ton. Bedload ranged from 5.2 to 76.7 grams per cross- channel sampling, equivalent to 0.11 to 1.70 tons per day. Sediment sampling during the storms indicates that bedload discharge is the primary mode of sediment transport. Suspended-sediment concentration ranged from 4 to 67 milligrams per liter; the median was 17 milligrams per liter. Bedload ranged from 3.4 to 862 grams per cross- channel sampling; the median was 109 grams. Only 15 percent of the samples were less than 50 grams. Scour chains and surveyed cross sections documented some scour and fill at most of the sites.Scour and fill tended to balance out; after a 1-year period, the net change in the streambed altitude was minimal. Some infilling was the net result at most of the sites. Surveys of the instream pond determined that the volume of sediment delivered to the pond from April 1993 to April 1994 was approximately 26,500 cubic feet. The average volume weight of the sediment was determined to be 102 pounds per cubic foot. The sediment yield for the upper reach of Juday Creek from April 1993 to April 1994 was estimated to be 48 tons per square mile.

Indiana

Historical and potential scour around bridge piers and abutments of selected stream crossings in Indiana

Historical scour data were collected by means of geophysical techniques and used to evaluate the scour-computation procedures recommended by the U.S. Federal Highway Administration and 12 other pub- lished pier-scour equations. Geophysical data were collected at 10 bridges in Indiana. For this evaluation it was assumed that the historical scour measured by use of geophysical techniques was associated with the peak historical discharge. The hydraulic conditions for the peak historical discharge were estimated by use of a model that computes water-surface profiles. For the evaluation, the results of the contraction and pier-scour equations were combined to determine a computed bed elevation, which was compared to the minimum historical bed elevation at the upstream end of the piers estimated from the geophysical data. None of the pier-scour equations accurately represented the historical scour at all of the study sites. On the basis of the limited data presented, the Federal Highway Administration procedures provided a combination of accuracy and safety, required by design equations, equal to or better than the other equations evaluated. The potential scour was com- puted according to the procedures recommended by the Federal Highway Administration. At two bridges, the procedures overpredicted historical scour by more than 10 feet, and at two other bridges, the proce- dure underpredicted historical scour by more than 5 ft therefore, the potential-scour computations need to be verified by additional data and sediment-transport modeling. Computed abutment scour appeared to be excessive at about half of the sites.

Indiana