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K. E. White

Publications and source records attributed to K. E. White.

9 recordsLinked to original sources
USGS2024

The LTAR cropland Common Experiment at Lower Chesapeake Bay

The Lower Chesapeake Bay (LCB) Long-Term Agroecosystem Research (LTAR) Common Experiment (CE) located in Beltsville, MD, focuses on research of concern to producers of the major regional crops, which are corn ( Zea mays L.), soybean [ Glycine max (L.) Merr.], wheat ( Triticum aestivum L.), and various forage species. Livestock production in the region includes broiler and laying chickens ( Gallus gallus domesticus L.) and dairy and beef cattle ( Bos taurus L.). The LCB region is among the most heavily populated in the United States. Urban development pressure is high for both farms and natural areas. The need to restore Chesapeake Bay water quality is a major influence on regional agricultural practices. Conservation practices such as cover cropping, no-till agriculture, and nutrient management planning are more common in the region compared to nationally. However, farmers still face management challenges implementing practices that address water quality and the rise of herbicide-resistant weeds. Researchers at the LCB site recognize the need to protect the Chesapeake and Delaware Bays and maintain farmer profitability. The LCB CE compares a 3-year crop rotation system featuring alternative crop management (cover crop intensification, crop rotation diversification, and integrated weed management [IWM]) with a prevailing 2-year system (no cover crops and no IWM), both under continuous no-tillage, to identify the optimal balance to promote the sustainability of regional cropping systems. The LTAR LCB site provides data-driven tools and solutions to support farmers in the mid-Atlantic region.

Delaware, Maryland, New Jersey, Pennsylvania, Virg↗
USGS1994

Determination of traveltime in the Delaware River, Hancock, New York, to the Delaware Water Gap by use of a conservative dye tracer

Traveltime of a soluble substance was determined for a 120-mile reach of the Delaware River from the confluence of the East Branch Delaware River and the West Branch Delaware River at Hancock, N.Y. to the Delaware Water Gap. Dye studies were conducted at the 85-95 percent and the 25-30 percent flow durations. Discharges ranged from 500-1,740 cubic feet per second during the 85-95 percent flow duration and 3,070-7,500 cubic feet per second for the 25-30 percent flow duration. The data were used to develop a set of time-concentration curves that would enable estimation of the traveltime of a spill at any point in the river within the study reach for 10 flow durations. The leading edge of a contaminant spill at Buckingham Access would take about 70 hours to reach the Delaware Water Gap when flows are at the 30-percent flow duration. The trailing edge (location of the dye cloud when concentrations would decrease to 10 percent of the peak concentration) would take about 50 hours after the arrival of the leading edge.

Water-Resources Investigations Report↗
USGS1990

Base-flow-frequency characteristics of selected Pennsylvania streams

Streamflow hydrographs of 309 streamflow stations in Pennsylvania were analyzed by using three computer-assisted empirical methods--local-minimum , fixed-interval, and sliding-interval--to separate the ground-water and surface-runoff components. The 2-, 5-, 10-, and 25-year base-flow-recurrence intervals were determined for each station. The 50- and 100-year recurrence intervals were determined for stations with minimums of 25 and 50 years of record, respectively. All active and inactive continuous-recording Pennsylvania streamflow stations with 10 or more years of record through water year 1986 were analyzed. Stations on the Delaware River in New York and New Jersey also were included. Hydrograph analysis by computer provides consistency of results by removing the subjectivity inherent in manual analyses and considerably reduces the time required to make the analyses. Estimates of the 25-year base-flow-recurrence interval made by using the local-minimum technique, which gives the most conservative estimate, range from 0.069 to 0.888 million gallons per day per square mile. Base flows estimated by using the three computer-assisted techniques compared well with published base flows estimated by using manual methods for three studies in southeastern Pennsylvania. Examples of the effects of geology, climate, regulation, and urbanization on base flow are provided.

Pennsylvania↗