Conference Papers

A flood hydrograph for an ungaged stream site can be estimated from a mean dimensionless hydrograph and estimates of instantaneous peak discharge (Q) and total storm runoff volume (V). However, the time base of the resulting flood hydrograph can be inversely related to the magnitude of the peak discharge if estimates of runoff volume were defined using ordinary least-squares regression...

Nonpoint-source contamination accounts for a substantial part of the water quality problems in many watersheds. The Wisconsin Nonpoint Source Water Pollution Abatement Program provides matching money for voluntary implementation of various best management practices (BMPs). The effectiveness of BMPs on a drainage-basin scale has not been adequately assessed in Wisconsin by use of data...

Deuterium (D) content of groundwater and precipitation, and tritium content of selected groundwater samples are used to infer flowpaths for groundwater in the Kilauea Volcano area. The spatial distribution of calculated recharge elevations and residence times for groundwater samples tends to support the idea that Kilauea's rift zones comprise leaky boundaries within the regional...

Nowhere are the problems of coastal wetland loss more serious and dramatic than in the Mississippi River deltaic plain region of south-central Louisiana. In that area, rates of shoreline erosion of 20 m.yr and loss of land area of up to 75 km/yr result from a complex combination of natural (delta switching, subsidence, sea-level rise, storms) and human (flood control, navigation, oil and...

There are three general characteristics of the data to be collected in a monitoring program that should be met in order to maximize the use and value of the data: the data quality should be known the data type and quality should be consistent and comparable, and the data should be available and accessible. Potential problems with each of these characteristics are addressed effectively by...

A quality control and quality assurance plan has been implemented as part of the Massachusetts bridge scour and channel-stability assessment program. This program is being conducted by the U.S. Geological Survey, Massachusetts-Rhode Island District, in cooperation with the Massachusetts Highway Department. Project personnel training, data-integrity verification, and new data-management

For a fixed cost, computing power increases 5 to 10 times every five years. The readily available computing resources have inspired new modal formulations and innovative model applications. Significant progress has been advanced in three-dimensional numerical estuarine modeling within the past three or four years. This paper attempts to review and summarize properties of new 3-D...

Depth of scour is measured as the vertical distance between scoured channel geometry and a measurement reference surface. A scour depth measurement can have a wide range depending on the method used to establish the reference surface. A consistent method to establish reference surfaces for bridge scour measurements is needed to facilitate transferability of scour data an scour analyses...

Data from assessments of channel stability and observed-scour conditions at 876 highway bridges over Maryland waterways were entered into a database. Relations were found to exist among specific, deterministic variables and observed-scour and debris conditions. Relations were investigated between (1) high-flow angle of attack and pier- and abutment-footing exposure, (2)abutment location...

Hydraulic properties, bridge geometry, and basin characteristics at 31 bridges in New York are being investigated to identify factors that affect local scour. Streambed elevations measured by the U.S. Geological Survey and New York State Department of Transportation are used to estimate local-scour depth. Data that show zero or minor scour were included in the analysis to decrease bias...

Laboratory investigation into the precision and accuracy of various mechanical-current meters are presented. Horizontal-axis and vertical-axis meters that are used for the measurement of point velocities in streams and rivers were tested. Meters were tested for repeatability and response to oblique flows. Both horizontal- and vertical-axis meters were found to under- and over-register...

No abstract available.