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Mason

Publications and source records attributed to Mason.

36 records · Page 2Linked to original sources
USGS2006

Monitoring Inland Storm Surge and Flooding from Hurricane Rita

Pressure transducers (sensors) and high-water marks were used to document the inland water levels related to storm surge generated by Hurricane Rita in southwestern Louisiana and southeastern Texas. On September 22-23, 2005, an experimental monitoring network of sensors was deployed at 33 sites over an area of about 4,000 square miles to record the timing, extent, and magnitude of inland hurricane storm surge and coastal flooding. Sensors were programmed to record date and time, temperature, and barometric or water pressure. Water pressure was corrected for changes in barometric pressure and salinity. Elevation surveys using global-positioning systems and differential levels were used to relate all storm-surge water-level data, reference marks, benchmarks, sensor measuring points, and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). The resulting data indicated that storm-surge water levels over 14 feet above NAVD 88 occurred at three locations, and rates of water-level rise greater than 5 feet per hour occurred at three locations near the Louisiana coast.

Fact Sheet↗
USGS2004

Evaluating a Radar-Based, Non Contact Streamflow Measurement System in the San Joaquin River at Vernalis, California

Accurate measurement of flow in the San Joaquin River at Vernalis, California, is vital to a wide range of Federal and State agencies, environmental interests, and water contractors. The U.S. Geological Survey uses a conventional stage-discharge rating technique to determine flows at Vernalis. Since the flood of January 1997, the channel has scoured and filled as much as 20 feet in some sections near the measurement site resulting in an unstable stage-discharge rating. In response to recent advances in measurement techniques and the need for more accurate measurement methods, the Geological Survey has undertaken a technology demonstration project to develop and deploy a radar-based streamflow measuring system on the bank of the San Joaquin River at Vernalis, California. The proposed flow-measurement system consists of a ground-penetrating radar system for mapping channel geometries, a microwave radar system for measuring surface velocities, and other necessary infrastructure. Cross-section information derived from ground penetrating radar provided depths similar to those measured by other instruments during the study. Likewise, surface-velocity patterns and magnitudes measured by the pulsed Doppler radar system are consistent with near surface current measurements derived from acoustic velocity instruments. Since the ratio of surface velocity to mean velocity falls to within a small range of theoretical value, using surface velocity as an index velocity to compute river discharge is feasable. Ultimately, the non-contact radar system may be used to make continuous, near-real-time flow measurements during high and medium flows. This report documents the data collected between April 14, 2002 and May 17, 2002 for the purposes of testing this radar based system. Further analyses of the data collected during this field effort will lead to further development and improvement of the system.

Open-File Report↗
USGS1994

Field performance of an acoustic scour-depth monitoring system

The Herbert C. Bonner Bridge over Oregon Inlet serves as the only land link between Bodie and Hatteras Islands, part of the Outer Banks of North Carolina. Periodic soundings over the past 30 years have documented channel migration, local scour, and deposition at several pilings that support the bridge. In September 1992, a data-collection system was installed to permit the off-site monitoring of scour at 16 bridge pilings. The system records channel-bed elevations at 15-minute intervals and transmits the data to a satellite receiver. A cellular phone connection also permits downloading and reviewing of the data as they are being collected. A digitally recording, acoustic fathometer is the main component of the system. In November 1993, current velocity, water-surface elevation, wave characteristics, and water temperature measuring instruments were also deployed at the site. Several performance problems relating to the equipment and to the harsh marine environment have not been resolved, but the system has collected and transmitted reliable scour-depth and water-level data.

Conference Paper↗
USGS1993

Low-flow characteristics of streams in North Carolina

Ten low-flow hydrologic areas were defined for North Carolina by relating topography, geology, mean annual runoff, and other features to low-flow frequency characteristics for 122 continuous-record streamflow stations and 396 partial-record streamflow stations. Regression equations relating low-flow characteristics to mean annual discharge were developed for five of the hydrologic areas covering 40% of the State, and statistical summaries of low-flow characteristics are given for all 10 hydrologic areas. Low-flow characteristics selected for analysis were the low-flow 7Q10, which is the annual minimum 7-day consecutive low flow, which on average will be exceeded in 9 out of 10 years--or stated another way, the probability is 10% that the 7-day consecutive low flow in any year will be less than the 7Q10; the low-flow W7Q10, which is similar to the low-flow 7Q10 except that it takes into account only the months from November through March; the low-flow 7Q2; and the low-flow 30Q2. Low-flow 7Q10's ranged from zero in some hydrologic areas in the Coastal Plain and Piedmont physiographic areas to a maximum value of 1.06 cu ft/sec/sq mi for a station in the western Piedmont and mountains physiographic area.

North Carolina↗