Robert M. Beall | USGS Science

USGS1976

Mean annual runoff in the upper Ohio River basin, 1941-70, and its historic variation

A map of the Ohio River basin above the Muskingum River shows patterns of mean annual runoff for the climatologic and hydrologic reference period, 1941-70. The primary data base consisted of 98 long-term gaging-station records collected within this 27,300-square-mile headwater area of the Ohio River basin. Supplemental information was derived from 83 short-term records. Mean annual runoff is at a regional minimum of less than 12 inches in an area extending from the northern West Virginia panhandle to the headwaters of the Mahoning River in Ohio. Mean annual runoff of more than 32 inches occurs in parts of the upper Cheat River basin in West Virginia. The zone of high runoff trends northeastward along the western slopes of the Allegheny Mountains; magnitudes diminish to about 25 inches at the eastern basin boundary near Ebensburg, Pennsylvania. Runoff of this magnitude occurs also in a band across the upper Allegheny River basin in Pennsylvania. Ratios of mean annual discharge to the 30-year reference-period average were computed for each year of record for all long-term gaging stations. Annual discharges have ranged from about 30 percent to 200 percent of the 30-year mean. Graphed summaries of the annual ratios document the relative duration and magnitude of wet and dry periods during the past 65 years in the upper Ohio River basin. (Woodard-USGS)

Open-File Report↗

USGS1975

Stream reconnaissance for nutrients and other water-quality parameters, Greater Pittsburgh Region, Pennsylvania

Eighty-five stream sites in and near the six-county Greater Pittsburgh Region were sampled in mid-June 1971 in mid-October 1972. Data are reported for 89 sites because 4 substitute sites were sampled in the second period. Drainage areas of the basins sampled ranged from 4.1 to 19,5000 square miles (10.6 to 50,500 square kilometres). The chemical analyses included constituents of three general classes: (1) nutrients, (2) activity indicators, and (3) dominant anions. Modification of the natural chemical and physical characteristics of the surface waters by man's activities is evident in some of the data. However, the activities are so diverse in type and in areal extent that their influence in terms of cause and effect is often obscure. Nutrient concentrations were high enough to indicate potential problems at about a quarter of the sampling sites. Temperature, dissolved oxygen, and pH values indicated a generally favorable capacity for regeneration or recovery from degradation, although a number a streams east of the Allegheny and Monongahela Rivers are marginal or lacking in the capacity. Regionally, sulfate is the dominant ion and was observed in concentrations of 40 milligrams per litre or more at 90 percent of the sites. Bicarbonate exceeded 100 milligrams per litre at 22 sites. A moderate to high degree of mineralization, as indicated by conductance readings of more than 500 micromhos per cetrimetre at half of the sampling sites, is a characteristic of the region's surface waters.

Pennsylvania↗