Project Summary:

Logistical regression equations are being developed for predicting the probability of a stream being “intermittent” or “perennial” in the State of Vermont. The regressions are based on actual flow regime observations at 400-600 small watershed sites. Site selection criteria include factors that have been successfully related to basin low-flow characteristics in previous studies in New England, such as drainage area, area of stratified-drift deposits, basin slope, basin aspect, channel slope, area of water bodies, area of wetlands, mean annual precipitation, basin elevation, basin centroid coordinates, relief, length of main channel, surficial geology and soil characteristics. Flow regime observations were made only during ‘normal' climatic and meteorological conditions defined by the State of Vermont. Logistical regression is being used to relate basin characteristics to a stream's ‘flow' or ‘no-flow' status at the time of observation.

This project will contribute to an increased understanding of the relations between flow regime in small upland watersheds and basin and climatic factors, and may eventually be used to improve the delineation of intermittent streams in USGS cartographic products and databases. Results will assist in the management of Vermont's water resources by producing consistent, hydrologically based determinations of a stream's status as perennial or intermittent. These determinations will be used for a wide variety of regulatory and planning efforts at the Federal, State, regional, county and town levels, including such applications as assessing fish and wildlife habitats, wetlands classifications, recreational opportunities, water-supply potential, waste assimilation capacities, sediment transport, and other water-quality and quantity conditions.

The product of this project will be a USGS Scientific Investigations Report describing the development and application of logistical regression equations for predicting the flow-regime of small streams in Vermont.