Geology topics

S. E. Morlock

Publications and source records attributed to S. E. Morlock.

6 recordsLinked to original sources

USGS2010

Flood-inundation maps for a 15-mile reach of the Kalamazoo River from Marshall to Battle Creek, Michigan

Digital flood-inundation maps for a 15-mile reach of the Kalamazoo River from Marshall to Battle Creek, Michigan, were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency to help guide remediation efforts following a crude-oil spill on July 25, 2010. The spill happened on Talmadge Creek, a tributary of the Kalamazoo River near Marshall, during a flood. The floodwaters transported the spilled oil down the Kalamazoo River and deposited oil in impoundments and on the surfaces of islands and flood plains. Six flood-inundation maps were constructed corresponding to the flood stage (884.09 feet) coincident with the oil spill on July 25, 2010, as well as for floods with annual exceedance probabilities of 0.2, 1, 2, 4, and 10 percent. Streamflow at the USGS streamgage at Marshall, Michigan (USGS site ID 04103500), was used to calculate the flood probabilities. From August 13 to 18, 2010, 35 channel cross sections, 17 bridges and 1 dam were surveyed. These data were used to construct a water-surface profile for the July 25, 2010, flood by use of a one-dimensional step-backwater model. The calibrated model was used to estimate water-surface profiles for other flood probabilities. The resulting six flood-inundation maps were created with a geographic information system by combining flood profiles with a 1.2-foot vertical and 10-foot horizontal resolution digital elevation model derived from Light Detection and Ranging data.

Michigan↗

USGS2004

USGS tethered ACP platforms: New design means more safety and accuracy

The US Geological Survey has developed an innovative tethered platform that supports an Acoustic Current Profiler (ACP) in making stream-flow measurements (use of the term ACP in this article refers to a class of instruments and not a specific brand name or model). The tethered platform reduces the hazards involved in conventional methods of stream-flow measurement. The use of the platform reduces or eliminates time spent by personnel in streams and boats or on bridges and cableway and stream-flow measurement accuracy is increased.

Hydro International↗

USGS2002

Discharge Measurements in Shallow Urban Streams Using a Hydroacoustic Current Meter

Hydroacoustic current-meter measurements were evaluated in small urban streams under a range of stages, velocities, and channel-bottom materials. Because flow in urban streams is often shallow, conventional mechanical current-meter measurements are difficult or impossible to make. The rotating-cup Price pygmy meter that is widely used by the U.S. Geological Survey and other agencies should not be used in depths below 0.20 ft and velocities less than 0.30 ft/s. The hydroacoustic device provides measurements at depths as shallow as 0.10 ft and velocities as low as 0.10 ft/s or less. Measurements using the hydroacoustic current meter were compared to conventional discharge measurements. Comparisons with Price-meter measurements were favorable within the range of flows for which the meters are rated. Based on laboratory and field tests, velocity measurements with the hydroacoustic cannot be validated below about 0.07 ft/s. However, the hydroacoustic meter provides valuable information on direction and magnitude of flow even at lower velocities, which otherwise could not be measured with conventional measurements.

Conference Paper↗

USGS2002

Hydroacoustic Current Meters for the Measurement of Discharge in Shallow Rivers and Streams

The U.S. Geological Survey (USGS) is evaluating the use of hydroacoustic current meters for making discharge measurements in shallow rivers and streams. The USGS historically has made discharge measurements in shallow rivers using mechanical, impellor-type current meters attached to a wading rod. The evaluation project has focused on three categories of hydroacoustic meters: an acoustic Doppler velocimeter (ADV) called a Flowtracker3, an acoustic Doppler velocity profiler (BoogieDopp), and bottom-tracking acoustic Doppler current profilers (ADCPs). The USGS role in this project includes providing USGS discharge-computation methods and algorithms to instrument manufacturers and evaluating instruments in the laboratory and field. An ADV (Flowtracker) designed for making discharge measurements in shallow rivers, has been tested in a USGS tow tank and was found to meet USGS calibration standards for mechanical, impellor-type current meters. The Flowtracker was field tested by USGS offices in five states; the tests were conducted by comparing discharge measurements made with the ADV to discharge measurements made with mechanical, impellor-type current meters. In general, the comparisons of Flowtracker performance to mechanical-meter results were favorable. An acoustic Doppler velocity profiler (BoogieDopp) is being evaluated for making discharge measurements in shallow rivers. The Boogiedopp will measure vertical velocity profiles at stationary positions across a channel, and the velocity profiles will be used to compute discharge. Discharge-computation software based on USGS methods and algorithms is under development for the acoustic Doppler velocity profiler. The USGS will evaluate bottom-tracking ADCPs from two manufacturers for making discharge measurements in shallow water. The bottom-tracking feature allows ADCPs to compute discharge from a moving platform as the platform moves across the channel.

Conference Paper↗

USGS1997

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↗

USGS1996

Evaluation of Acoustic Doppler Current Profiler measurements of river discharge

Developments in Acoustic Doppler Current Profiler (ADCP) technologies have made these instruments potentially useful for making measurements of discharge in rivers and large streams. Although there have been several laboratory studies and some field experiments, quantitative information on the performance of ADCP's under field conditions is relatively rare but essential to proper assessment of the potential uses and limitations of these instruments. This study was a comparative evaluation of river discharge data and ADCP data collected with conventional methods at 12 selected U.S. Geological Survey streamflow- gaging stations in the continental United States. ADCP discharge measurements were made at the 12 sites in 1994. Twenty-six of the 31 measurements differed by less than 5 percent from the discharges determined with conventional methods. All 31 ADCP measurements were within 8 percent of the conventional method discharges. The standard deviations of the ADCP measurements ranged from approximately 1 to 6 percent and were generally higher than the measurement errors predicted by error-propagation analysis of ADCP instrument performance. These error-prediction methods assume that the largest component of ADCP discharge measurement error is instrument related. The larger standard deviations indicate that substantial portions of measurement error may be attributable to sources unrelated to ADCP electronics or signal processing and are functions of the field environment.

Water-Resources Investigations Report↗