This project is an effort to adapt existing hydroacoustic current meters for the purpose of
measuring discharges in rivers and streams at wading depths.
During summer and early fall 1999, much of Indiana experienced record-low streamflows because of a period of drought. During such lowflow periods, government agencies, private firms, and the general public are in need of accurate streamflow records from the State's network of streamflow-gaging stations. The accuracy of the streamflow record is largely dependant upon the accuracy of discharge measurements made in the field. Traditionally, the USGS has relied upon mechanical current meters to make discharge measurements. At very low flows, mechanical current meters have limitations that can reduce the accuracy of discharge measurements. As a result, in fall 1999, the USGS Indiana District office began to investigate alternative technologies and methods for measuring discharges in shallow streams. Several commercially available hydroacoustic current meters showed potential for use in shallow streams.
In August 2000, the Indiana District office submitted a project proposal to the USGS Instrument Committee (ICOM) to guide the adaptation of existing hydroacoustic current meters for the measurement of discharge in shallow rivers and streams. The project received funding for the 2001 Federal fiscal year (October 1, 2000, to September 30, 2001).
In the 2001 fiscal year, the project will concentrate on two different instruments from two different vendors for this application. One instrument is a point-velocity meter that has the potential for use in streams with depths as shallow as 1 inch and velocities below 0.10 feet per second (ft/s). The second instrument has the potential to measure vertical-velocity profiles in depths as shallow as 6 inches.
Acoustic Doppler profilers with bottom tracking already have been fully integrated into USGS
routine streamflow-gaging operations. These instruments are deployed from a moving
platform in water depths that are generally greater than 3 feet (click here for more
information). This project is designed to apply hydroacoustic technologies for
discharge measurements in waters shallower than 3 feet. If this project is successful, the
USGS could use hydroacoustic current meters in nearly the entire range of flow conditions in
many streams and rivers.
This project is overseen by ICOM and the USGS Office of Surface Water Hydroacoustic
Workgroup. The USGS Indiana District office and Maryland-Delaware-D. C.
District offices are partnering on the point-velocity application development. Other USGS
district offices, including Florida, New Hampshire, Kentucky, and Idaho have expressed
interest in participating in instrument testing. While no formal agreements have been
entered into with the instrument vendors, the vendors have contributed resources to this
effort.
Funding sources for this project include:
A Notification of Instrument Need, Instrument Development Project Proposal, and project update reports reside on ICOM's web pages (USGS access only). Project updates also will be posted on these pages in Project Updates.
| Main |
| Introduction |
| Wading Discharge Measurements |
| Hydroacoustic Technologies for Wading Discharge Measurements |
| Project Progress |
| Project Plans |
| Project Updates |
| References |
Indiana District Hydroacoustics Main Page
Office of Surface Water Hydroacoustic Support Pages
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