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R.H. Simmons

Publications and source records attributed to R.H. Simmons.

18 recordsLinked to original sources
USGS1997

Water resources data Maryland and Delaware, water year 1996, Volume 1. Surface-water data

Water resources data for the 1996 water year for Maryland and Delaware consist of records of stage, discharge, and water quality of streams; stage and contents of lakes and reservoirs. This volume (Volume1. Surface-Water Data) contains records for water discharge at 90 gaging stations; stage and contents 1 reservoir; and water quality at 22 gaging stations. Also included are data for 4 crest-stages and 6 tidal crest-stage partial-record stations. Additional water data were collected at various sites not involved in the systematic data-collection program and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and cooperating State, local, and Federal agencies in Maryland and Delaware

Delaware, Maryland↗
USGS1995

Storm and flood of July 5, 1989, in northern New Castle County, Delaware

On July 5, 1989, intense rainfall from the remnants of Tropical Storm Allison caused severe flooding in northern New Castle County, Delaware. The flooding claimed three lives, and damage was estimated to be $5 million. Flood conditions were aggravated locally by rapid runoff from expansive urban areas. Record- breaking floods occurred on many streams in northern New Castle County. Peak discharges at three active, continuous-record streamflow-gaging stations, one active crest-stage station, and at two discontinued streamflow-gaging stations exceeded previously recorded maximums. Estimated recurrence intervals for peak flow at the three active, continuous-record streamflow stations exceeded 100 years. The U.S. Geological Survey conducted comprehensive post-flood surveys to determine peak water-surface elevations that occurred on affected streams and their tributaries during the flood of July 5, 1989. Detailed surveys were performed near bridge crossings to provide additional information on the extent and severity of the flooding and the effects of hydraulic constrictions on floodwaters.

Water-Resources Investigations Report↗
USGS1978

Technique for estimating magnitude and frequency of floods in Delaware

A flood-estimating method is presented which applies to drainage basins in Delaware without urban development and covers selected recurrence intervals from 2 to 100 years. The method was developed by multiple-regression techniques. The State is divided into two regions and sets of equations for calculating peak discharges based on physical basin characteristics are provided for each region. The boundary between regions generally corresponds with the division between the Piedmont and Coastal Plain provinces. In the northern region, flood-peak discharges were related to basin drainage area and storage. In the southern region, flood peaks were related to drainage area, slope, storage, forest cover, and two composite soil categories. Standard errors of estimate for the regression equations in the northern region ranged from 30 to 39 percent. For the southern region, the standard errors of estimate varied from 38 to 40 percent. Without using the two soil parameters in the southern region, the standard errors of estimate varied from 57 to 70 percent. Annual flood peaks, basin characteristics, and flood-frequency distributions are tabulated for the 60-gaged sites used in the regression analysis. At 23 of these sites, a rainfall-runoff model generated additional flood-peak data which were used in defining the flood-frequency distributions. (Woodard-USGS)

Delaware↗