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Research about Louisiana

Source-linked reports with geographic coverage including Louisiana.

At least 775 records · Page 43Linked to original sources
USGS1989

Water resources data, Louisiana, water year 1988

Water resources data for the 1988 water year for Louisiana consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground water. This report contains records for water discharge at 61 gaging stations; stage only for 19 gaging stations and 7 lakes; water quality for 39 surface-water stations (including 15 gaging stations), and 118 wells; and water levels for 215 observation wells. Also included are data for 103 crest-stage and flood-profile 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 and Federal agencies in Louisiana.

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USGS1989

Erosion and deterioration of the Isles Dernieres Barrier Island Arc, Louisiana, U.S.A.: 1853 to 1988

Using cartographic and aerial photography data from the years 1853, 1890, 1934, 1956, 1978, 1984, and 1988, shoreline change maps of the Isles Dernieres barrier island arc were constructed. These data were accurately superimposed, using a computer mapping system, which removed projection, datum, scale, and other cartographic inconsistencies. Linear, areal, and perimeter measurements indicate that the Isles Dernieres are suffering rapid rates of coastal erosion, land loss, and breakup. Bayside and gulfside erosion, in combination with sediment shortage and subsidence, have caused the Isles Dernieres to narrow through time. In addition, the core of the barrier island arc does not migrate landward and instead, breaks up in place as a result of inlet breaching and development. This is in contrast to other models of landward barrier island migration during transgression. If these trends continue, the Isles Dernieres will likely evolve into a subaqueous inner-shelf shoal by the early 21st century. Loss of the Isles Dernieres barrier island arc will severely impact the Terrebonne parish estuary, resulting in decreased environmental quality and increased public risk from storms and hurricanes.

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USGS1989

Trends in wintering canvasback populations at Catahoula Lake, Louisiana

Aerial survey data (1968-1989) and water gauge readings (1958-1989) were examined to detennine trends in and relationships between canvasback (Aythya valisineria) populations and water levels at Catahoula Lake, Louisiana. Wintering canvasback populations at Catahoula Lake have increased over the past 21 years. A peak population estimate of 78,000 canvasbacks was recorded in January 1988. There was a significant relationship between increases in wintering canvasback numbers and increased November water levels. No significant changes in December or January water levels nor relationships between wintering canvasback numbers and December or January water levels could be detected. In recent years, Catahou1a Lake has become one of the most important canvasback wintering areas in North America. We conclude that the increased availability of open water feeding habitat has been a major factor in the increased usage of Catahoula Lake by canvasbacks.

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USGS1988

Environmental impacts and regulatory policy. Implications of spray disposal of dredged material in Louisiana wetlands

The capabilities of a new wetland dredging technology were assessed along with associated newly developed state and federal regulatory policies to determine if policy expectations realistically match the technological achievement. Current regulatory practices require amelioration of spoil bank impacts upon abandonment of an oil/gas well, but this may not occur for many years or decades, if at all. Recently, a dreding method (high-pressure spray spoil disposal) was developed that does not create a spoil bank in the traditional sense. Its potential for reducing environmental impacts was recognized immediately by regulatory agencies for whom minimizing spoil bank impacts is a major concern. The use of high-pressure spray disposal as a suitable alternative to traditional dreding technology has been adopted as policy even though its value as a management tool has never been tested or verified. A qualitative evaluation at two spoil disposal sites in saline marsh indicates that high-pressure spray disposal may indeed have great potential to minimize impacts, but most of this potential remains unverified. Also, some aspects of current regulatory policy may be based on unrealistic expectations as to the ability of this new technology to minimize or eliminate spoil bank impacts.

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USGS1988

Habitat relationships of island nesting seabirds along Coastal Louisiana

Seabirds in the saline marsh of coastal Louisiana nest on the islands that are more isolated, smaller, have lower percentages of woody vegetation, and higher percentages of herbaceous vegetation and beach habitat. Only moderate variation in these habitat features was demonstrated among years of colonization. The factors causing these preferences appear to be protection from mammalian predators and presence of suitable nesting habitat. Forster's Terns colonized islands with a lower beach percentage than those colonized by Laughing Gulls or Black Skimmers due to interspecific differences in preferred nesting substrate. Nest site tenacity was weak in that the majority (57%) of colonies was active during only one of the three years of survey. Extreme nest site tenacity is probably selected against in these highly unstable wetlands. However, those islands colonized perennially were more geographically isolated and had higher percentages of beach cover. The relationship between seabird nesting abundance and the habitat variables was low, implying a lack of fine tuning of population numbers to habitat at a local scale. Numerous islands potentially suitable for colonization by seabirds may exist along coastal Louisiana. But the presence of alternative nesting islands may be required due to the ever changing nature of these saline marsh wetlands.

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USGS1988

Eustrongylides sp. epizootic in young common egrets (Casmerodius albus)

In May 1985, epizootic mortality was reported in common egrets ( Casmerodius albus ) on Avery Island, Louisiana. Subsequent investigation revealed that more than 400 birds died. Severe peritoneal nematodiasis ( Eustrongylides sp.) was found on postmortem examination. A nearby breeding rookery on the same island was apparently unaffected. Reasons for this selective mortality are presented. Three other reports of epizootic mortality due to Eustrongylides sp. have been reported. This is the first report of this type of epizootic in gulf-coast birds.

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USGS1988

Water resources data, Louisiana, water year 1987

Water resources data for the 1987 water year for Louisiana consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground water. This report contains records for water discharge at 63 gaging stations; stage only for 19 gaging stations and 7 lakes; water quality for 48 surface-water stations (including 19 gaging stations), 6 lakes, and 77 wells; and water levels for 346 observation wells. Also included are data for 103 crest-stage and flood-profile 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 and Federal agencies in Louisiana.

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USGS1987

Seismicity map of the state of Louisiana

This map is one of a series of seismicity maps produced by the U.S. Geological Survey that show earthquake data of individual states or groups of states at the scale of 1:1,000,000. This map shows only those earthquakes with epicenters located within the boundaries of Louisiana, even though earthquakes in nearby states may have been felt or may have caused damage in Louisiana. The data in table 1 were used to compile the seismicity map; these data are a corrected, expanded, and updated (through 1987) version of the data used by Algermissen (1969) for a study of seismic risk in the United States. The locations and intensities of some earthquakes were revised and intensities were assigned where none had been before. Many earthquakes were added to the original list from new data sources as well as from some old data sources that has not been previously used. The data in table 1 represent best estimates of the location of the epicenter, magnitude, and intensity of each earthquake on the basis of historical and current information. Some of the aftershocks from large earthquakes are listed, but not all, especially for earthquakes that occurred before seismic instruments were universally used.

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USGS1987

Water resources data, Louisiana, water year 1986

Water resources data for the 1986 water year for Louisiana consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground water. This report contains records for water discharge at 70 gaging stations; stage only for 17 gaging stations and 11 lakes; water quality for 56 surface-water stations (including 24 gaging stations), 6 lakes, and 113 wells; and water levels for 398 observation wells. Also included are data for 136 crest-stage and flood-profile 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 and Federal agencies in Louisiana.

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USGS1987

Louisiana ground-water map no. 1: Potentiometric surface, 1985, and water-level changes, 1983-85, of the Chicot aquifer in southwestern Louisiana

The Chicot aquifer is the principle source of groundwater in southwestern Louisiana and is the most extensively pumped (nearly 1 billion gallons per day) aquifer in the State. Withdrawals from the Chicot aquifer are used primarily for irrigation. Two maps show the generalized potentiometric surfaces of the upper sand unit ('200-ft ' sand in the Lake Charles area) and the ' 500-ft ' sand of the Chicot aquifer. General water level altitudes and flow directions may be inferred from these maps which were prepared in cooperation with the Louisiana Department of Transportation and Development, Office of Public Works. Previous studies of groundwater hydrology in southwestern Louisiana are included in selected references.

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USGS1986

Generalized potentiometric surface of the Catahoula aquifer in central Louisiana, 1980

Generalized contours of the altitude of water levels in wells completed in the Catahoula aquifer in central Louisiana, are illustrated by this map. Most water level measurements used in compiling the map were made in 1980; however, in parts of the State where water levels from 1980 were unavailable and where evidence indicated little change in water level, some measurements from as early as 1961 and as late as 1982 were used. Groundwater levels in and near the outcrop areas fluctuate 2 ft or less yearly and no significant long-term declines have occurred. The slow downward trend in water level altitude since early 1976 may be caused by pumpage from the Catahoula aquifer by a rural water system approximately 3 miles away. Recharge to the Catahoula aquifer occurs by rainfall on the upland outcrop-subcrop areas. Saltwater occurs throughout the Catahoula aquifer downgradient from the outcrop area. The ' approximate limit of freshwater ' line on the map indicates the downgradient limit of water with a concentration of chloride < 250 mg/L; the line was determined using water quality data and analysis of resistivity curves from geophysical well logs. Water from the Catahoula aquifer is used for municipal, industrial, and domestic purposes. Total pumpage from the aquifer in Louisiana was slightly over 1.1 million gallons/day in 1980. Local cones of depression result from pumpage just east of Anacoco in Vernon Parish and northwest of Jonesville in Catahoula Parish. (Lantz-PTT)

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USGS1986

Louisiana hydrologic atlas map no. 1: Mean annual runoff in Louisiana

The map shows the mean annual runoff from drainage basins in Louisiana exclusive of those in the coastal zone and the alluvial valleys of the Mississippi, Ouachita, and Red Rivers. The mean annual runoff for the State of Louisiana varies from 0.7 (cu ft/s)/sq mi in the Sabine and Red River basins to >2.0 (cu ft/s)/sq mi in the upper reaches of the Mermentau River. Factors that account for the three-fold variation in runoff across Louisiana include regional differences in rainfall, varying physical characteristics of the land, and differing land use patterns. The mean annual runoff was determined on the basis of continuing measurements of stage and discharge of uncontrolled streams. The periods of record from the 88 stations shown on the map vary from 5 to 25 yr. The 88 stations were grouped into seven categories of runoff. The boundaries for each region generally correspond to drainage boundaries or physiographic boundaries.

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