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Research about North Carolina, Virginia

Source-linked reports with geographic coverage including North Carolina, Virginia.

72 records · Page 4Linked to original sources
USGS1994

Flow and salinity in West Neck Creek, Virginia, 1989-92, and salinity in North Landing River, North Carolina, 1991-92

Flow and salinity were monitored during 1989-92 in West Neck Creek, Virginia, which provides a direct hydraulic connection between the brackish waters of Chesapeake Bay and the relatively fresh waters of Currituck Sound. During the 308 days for which data were available, flow was to the south 64 percent of the time, but 80 percent of the southward flows were less than 40 cubic feet per second. Flows ranged from 356 cubic feet per second to the south to 50 cubic feet per second to the north, and the highest flows were associated with precipitation events. Salinity ranged from less than 0.1 to 24.5 parts per thousand, and the highest salinities were observed during periods of sustained, high northerly winds. Salt transport ranged from 34,510 tons per day to the south to 302 tons per day to the north.

North Carolina, Virginia↗
USGS1994

Land use in, and water quality of, the Pea Hill Arm of Lake Gaston, Virginia and North Carolina, 1988-90

The City of Virginia Beach currently (1994) supplies water to about 400,000 people in southeastern Virginia. The city plans to withdraw water from the Pea Hill Arm of Lake Gaston to meet projected water needs of the population to the year 2030. The purpose of this report is to (1) describe the temporal and spatial distribution of selected water-quality constituents, (2) document current (1989) land use and land cover in the Pea Hill Arm drainage basin, and (3) discuss relations, if any, between the quality of water in the inlets within the Pea Hill Arm and land uses. The report focuses on water-quality problems in the basin, including changes in concentrations of major ions, nutrients, and algae associated with urban development adjacent to water bodies. The Pea Hill Arm was classified as mesotrophic on the basis of the range of concentrations of total phosphorus (0.001 to 0.61 milligrams per liter); the range of concentrations of total organic-plus-ammonia nitrogen (0.2 to 1.4 milligrams per liter); and the range of concentrations of chlorophyll a (1.4 to 56 micrograms per liter). These water-quality data were collected at 3 feet below the water surface during water years 1989-90. Thermal stratification in Pea Hill Arm generally began in April and ended in September. Water below a depth of about 25 feet generally became anoxic by June. Destratification generally began in late September and was completed by November. Lake Gaston followed the same general stratification and destratification pattern as Pea Hill Arm, except Lake Gaston was partially destratified during the summer when large amounts of water were released from John H. Kerr Reservoir and Lake Gaston Dams. During water year 1988, streamflows were 33 percent below the long-term mean-annual streamflows at one of the major streams to Lake Gaston. Low streamflows contributed to elevated specific conductances and concentrations of sodium, calcium, magnesium, and alkalinity from October 1988 to February 1989 at sampling stations in the Pea Hill Arm and Lake Gaston. About 75 percent of the land use in the Pea Hill Arm is forest land. The remaining 25 percent of the Pea Hill Arm drainage basin is 8 percent pasture/open land, 8 percent open water, 6 percent residential land, and 3 percent cropland. No statistical relations are present between water-quality constituents measured and developed land uses within 11 basins in the Pea Hill Arm Basin, except during periods of stormwater runoff. During a stormwater-runoff event, there was a relation between total nitrite plus nitrate and land use (Kendall's tau correlation coefficient of 0.69). The relation between the developed land use and total nitrite plus nitrate can also be related to the increased ground-water inputs during high base-flow periods. Spatial differences in water-quality constituents as determined by Wilcoxon (matched-pairs) signed-rank tests and cluster analyses were longitudinal and primarily grouped into riverine, transition, and lacustrine zones. These zones were grouped on the basis of flow characteristics and nutrient concentrations.

North Carolina, Virginia↗
USGS1993

Water-quality data from continuously monitored sites in the Albemarle Sound estuarine system, North Carolina, 1989-91

Water-quality measurements were made at 11 sites in or near North Carolina?s Albemarle Sound. Measurements taken at 15-minute intervals included near-surface and near-bottom specific conductance; near-surface water temperature; and near-surface, mid-depth, and near-bottom dissolved-oxygen concentrations. Salinities generally ranged from less than 0.1 to about 32 parts per thousand during the period October 1989 through September 1991. Recorded water temperatures were between zero and 35 degrees Celsius during the measurement period. Dissolved-oxygen concentrations ranged from less than 1 milligram per liter to 19 milligrams per liter. Daily mean values of specific conductance; salinity; water temperature; dissolved-oxygen concentrations; and dissolved oxygen, percent saturation, are presented in tables and graphs. Five-day mean values of water temperature and dissolved-oxygen concentrations for day and night conditions are also presented in tables.

North Carolina, Virginia↗
USGS1990

Water-quality trends and basin activities and characteristics for the Albemarle-Pamlico estuarine system, North Carolina and Virginia

The Albemarle-Pamlico estuarine system has a total basin area of nearly 31,000 square miles and includes the Neuse, Tar, Pamlico, Roanoke, Chowan, and Alligator Rivers, and the Albemarle, Pamlico, Currituck, Croatan, and Roanoke Sounds. Albemarle Sound receives the greatest freshwater inflow of all the sounds in the estuarine system. Inflow to this sound averages about 13,500 cubic feet per second. Inflow to Pamlico Sound from the Pamlico River averages around 5,400 cubic feet per second, and average inflow into the Neuse River estuary is about 6,100 cubic feet per second. Approximately one-half of the inflow into the system is from ground-water discharge. The Neuse River basin has had the greatest increases in wastewater discharges (650 percent since the 1950's) and had the greatesttotal wastewater discharges of any of the basins in the study area, averaging about 200 million gallons per day in 1988. Wastewater discharges into the Neuse and Tar Rivers were nearly equal to the 7-day, 10-year low flows for these rivers. Land-use data compiled in 1973 for the lower parts of the Neuse River basin and lower part of the Tar-Pamlico River basin indicate that 25 percent of the area was evergreen forest, 25 percent was forested wetlands, 20 percent was cropland and pasture, 12 percent was mixed forest, 10 percent was nonforested wetland, and 4 percent was urban. The amount of nonforested wetland in the part of the study area along the Outer Banks declined 6.5 percent from 1973 to 1983. The numbers of farms and acreage in agricultural use in the study area have declined since the 1920's. A decrease of more than 60 percentin the number of farms was shown between the early 1950's and 1982. Fertilizer sales increased through the 1970's, but declined in the 1980's. Manufacturing employment has increased in the last 30 years, while agricultural employment has decreased. Data from seven stations of the U.S. Geological Survey National Stream Quality Accounting Network were used to evaluate water quality for the major streams flowing into the Albemarle-Pamlico estuarine system. Water-quality data for 296 stations in the estuarine system were examined for the period 1945-88. The statistical test used for trend analysis was the Seasonal Kendall test (Hirsch and others, 1982). This nonparametric procedure is useful for analyses of water-quality properties that show non-normally distributed frequency distributions. The Seasonal Kendall trend analyses of water-quality data indicate that change has occurred in the water quality of the Albemarle-Pamlico estuarine system from 1945 to 1988. Dissolved-oxygen concentrations increased at a mean rate of 0.1 milligram per liter per year throughout the estuarine system, except in the Chowan River where decreases of approximately 0.06 milligram per liter per year occurred. In general, pH increased in streams throughout the area at a mean rate of 0.04 pH unit per year, except in the Pamlico River where pH decreased by 0.03 pH unit per year. A general increase in pH and dissolved-oxygen concentrations (if daytime measurements) might be indicative of more productive estuary conditions for algal growth. Suspended-solids concentrations decreased throughout the area at a mean rate of 1.1 milligrams per liter per year, probably as a result of a general decrease in suspended inorganic material. Increasing trends of salinity concentrations, as much as 0.1 part per thousand per year, were detected in Albemarle Sound. Total ammonia plus organic nitrogen concentrations decreased (-0.03 milligram per liter per year) in streams throughout most of the area but increased (0.02 milligram per liter per year) in the Pamlico River. However, ammonia nitrogen concentrations decreased (-0.0035 milligram per liter per year) in the Pamlico River; therefore, increases in organic nitrogen probably caused the observed increase in combined ammonia plus organic nitrogen concentrations. This probably results from increas

North Carolina, Virginia↗
USGS1990

Water withdrawals in the Roanoke-Chowan Subregion of North Carolina and Virginia, 1983

The Chowan-Roanoke Subregion of North Carolina and Virginia comprises an area of about 18,300 sq mi, of which 7,600 sq mi are in North Carolina and 10,700 sq mi are in Virginia. Precipitation in the region is relatively high, and therefore water supplies appear to be plentiful. However, projected increases in water withdrawals, proposed interbasin diversions, and limited storage could reduce the amount of water available to meet the water use demand in the region. This report summarizes water withdrawals for the relatively dry year 1983 by type of use and county for the Subregion. Total surface and groundwater withdrawals in the Subregion were about 3,660 million gal/day; 95% was withdrawn in North Carolina where large amounts of water were withdrawn at four thermoelectric powerplants. Self-supplied industries accounted for the second largest withdrawal of water (206 million gal/day), which was 55% of the water withdrawals excluding power generation. Also, industries accounted for about 57% of the total groundwater withdrawals in the Subregion.

North Carolina, Virginia↗
USGS1979

Tree rings as indicators of hydrologic change in the Great Dismal Swamp, Virginia and North Carolina

Analyses of tree rings of large, canopy loblolly pines ( Pinus taeda L.,) growing near a drainage ditch in the Great Dismal Swamp have indicated that the tree rings are datable and hydrologically (climatically) sensitive. Climatic and prior growth factors in regression explained 87 and 71 percent of the variance of the preditching and postditching earlywood widths, respectively, and 82 and 7O percent of the latewood widths for the same time periods. Early summer precipitation was significantly, and positively, correlated with preditching latewood growth. When pre and postditching records were merged into a single record, regression analysis explained less growth variation than when the two time periods were considered individually, implying a change in growth response following ditching. Prior to ditching, growth was most limited by dry summers which followed dry summers. After ditching, growth was less strongly linked with precipitation and more strongly linked with temperature. Regression results are compatible with the contention that growing season water levels in the proximity of the collection site have been lower since ditching.

North Carolina, Virginia↗
USGS1978

Premetamorphic hydrothermal origin of the Tungsten Queen vein, Hamme District, North Carolina, as indicated by mineral textures and minor structures

The Hamme Tungsten district is a 13-km long, 2-km wide, northeast-trending belt located in northern Vance County, North Carolina and southern Mecklenburg County, Virginia (Fig. 1). The district contains the largest quartz-wolframite-type vein deposits in the United States. Over 50 tungsten-bearing veins occur in this area (Espenshade, 1947), from which more than 1 million short ton units of WO 3 have been produced since World War II Mining terminated in 1971 after a sharp drop in the price of tungsten; currently, the district is inactive.

North Carolina, Virginia↗
USGS1977

Distribution of some biostratigraphically diagnostic ostracodes in the Pliocene and lower Pleistocene of Virginia and northern North Carolina

Ostracodes are abundant and diverse in Pliocene and lower Pleistocene deposits of Virginia and North Carolina. Many readily identified species are short ranging or have well-defined beginning and (or) end points to their stratigraphic range. These microscopic crustaceans, therefore, are very useful in zonation and correlation in the region. In this paper, 54 particularly useful species are illustrated, and their ranges are indicated graphically. The range zones, concurrent range zones, and local range zones of these forms allow the recognition of the chronozones of previously proposed ostracode assemblage zones in Virginia and North Carolina as well as in other regions.

North Carolina, Virginia↗
USGS1974

Hydrology of the Dismal Swamp, Virginia-North Carolina

The Dismal Swamp, on the border between eastern Virginia and North Carolina is one of the few remaining large (approximately 210,000 acres) areas of wet wilderness in the eastern United States. There has been much speculation concerning the hydrologic conditions that led to the formation of the swamp. Oaks and Coch (1973) recently completed a detailed investigation of the geology and morphology of the area. An analysis of their geology and the pollen work of Whitehead (1972) has lead the authors to the following hypothesis concerning the hydrologic conditions that led to the formation of the peat in the swamp. A permeable sand facies of the Norfolk Formation underlies Dismal Swamp. This facies was originally completely covered by the Sand Bridge Formation, which is a confining layer, and underlain by the impermeable Yorktown Formation. Movement of water eastward within the Norfolk Formation from the outcrop area on the top of the Suffolk Scarp was further restricted by a less permeable facies of the Norfolk east of the swamp; thereby creating an artesian head within the permeable sand facies of the Norfolk Formation. Erosion during the Pleistocene age breached the Sand Bridge confining layer and allowed upward seepage of water along the shallow stream valleys. This seepage, combined with the abundant rainfall and naturally sluggish surface drainage, may have been sufficient to trigger the formation of peat along stream valleys about 9,000 years ago. The peat further inhibited surface drainage, which in turn, accelerated the accumulation of peat until the interfluve areas were covered. The present role of the Norfolk Formation in the hydrology of the swamp is not clear, but it is considered to be one of the most important aspects of the hydrology to be studied in future investigations. Surface inflow is from small streams draining from the west. The flow of these streams varies widely, being generally less in the summer than in winter. Outflow is primarily through the Feeder Ditch-Dismal Swamp Canal system, which discharges at South Mills and Deep Creek locks. Rates and direction of surface flow within the swamp are partly controlled by gates on many of the ditches. Inadequately controlled ditches penetrating the Norfolk Formation plus withdrawal of water from wells along Suffolk Scarp have altered the flow of ground water under the swamp. These modifications and the loss of water through the Dismal Swamp Canal have probably resulted in a generally drier swamp as indicated by changes in the vegetation. It is feasible to preserve Dismal Swamp, but more detailed studies of the hydrology are needed to aid in future management.

North Carolina, Virginia↗
USGS1957

Water resources of the Yadkin-Pee Dee River basin, North Carolina

Sufficient water is available in the basin of the Yadkin and Pee Dee Rivers to meet present requirements and those for many years to come if water use increases at about the present rate. Data presented in this report show that the average annual streamflow from approximately 82 percent of the basin area during the 25-year period, 1929-53, was about 6,200 mgd, representing essentially the total available water supply. Comparison of the available water supply to the estimated withdrawal use (excluding water power) of both surface and ground water of 600 mgd indicates the relative utilization of the water resources of the basin at present. If proper pollution controls are observed and practiced so that water in the various streams may be reused several times, the potential water available is even greater than indicated by the above comparison. Preliminary studies indicate that the quantity of water now being withdrawn from ground-water reservoirs in the basin is only a fraction of the total that may be obtained from this source. Twenty-eight of the 64 municipalities having public water-supply systems use surface water; however, as the largest cities in the area use surface supplies, about 85 percent of the water used for public supplies is from surface sources. Of the 20 complete-record stream-gaging stations now in operation in this area 7 have been in operation for 24 years or longer. Periodic measurements of the rate of flow have been made at 31 additional sites on streams scattered widely over the basin. All available streamflow data including those for 1953 are summarized in either graphic or tabular form, or both. Because of the critically low flows occurring during the drought of 1954, several illustrations include data for 1954 and the early months of 1955 for comparison with the minima of previous years. Adequate water for domestic use is available from wells throughout the basin. The consolidated rocks of the Piedmont furnish water for small industries and for municipalities whose population is less than about 1,500. The yields of wells in rock range from less than 1 gpm to as much as 200 gpm with local, rather than regional, geologic factors controlling the yield. The average municipal well in consolidated rocks yields about 30 gpm. In contrast, the sands of the Coastal Plain, in the eastern part of the basin, furnish as much as 500 gpm to individual wells, and ground-water conditions are generally similar throughout that region. A cumulative deficiency in rainfall from 1953 to 1955, has caused ground-water levels to fall below the seasonal averages, but the decline is thought not to indicate a long-term trend. The most serious problem involving future use of ground water is the lack of knowledge of the characteristics of the ground-water provinces in the basin. Generally the chemical quality of the surface waters in the Yadkin-Pee Dee River basin is good. They are low in mineral matter and soft, although some of the surface water contains excessive quantities of iron. In some local areas the streams have been polluted by municipal and industrial wastes. During periods of high runoff many of the streams transport large quantities of suspended sediment. Tributary streams in the lower eastern part of the basin are highly colored because of drainage from swampy areas. Ground water from the consolidated rocks in the Piedmont region is more variable in quality than water from other areas in the basin. The dissolved solids in water from the consolidated rocks ranged from 26 to 1,480 ppm with a median of 109 ppm. Wells in the Cretaceous clay province normally yield slightly acid waters. The pH ranges from 4.7 to 7.7 with a median of 5.3. Generally ground water in this province is extremely soft and low in dissolved solids. Wells in the Cretaceous sand province yield a sodium bicarbonate type of water ranging in hardness from 2 to 130 ppm.

North Carolina, Virginia↗