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Articles 661 - 672 of 672

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation Jan 1971

Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation

Publications (WR)

Progressive increases in concentration of dissolved solids in the Colorado River water from Lake Powell to Imperial Dam seem to alter plankton dynamics and biological productivity of the river. Also, changes in biological productivity and micronutrients concentrations occur within the same reservoir. Development of a digital simulation model to predict micronutrients concentrations and biological productivity is necessary for diagnosing changes in plankton population and effluent-carrying capacity of the system. The objectives of the study are: (1) to determine trace metal balance at different locations in Lake Mead, (2) to measure biological productivity and conduct plankton population counts at each sampling …


Fishery Report Iv (4) - Report On The Barramundi Fishery In Western Australia, N M. Morrissy Jan 1969

Fishery Report Iv (4) - Report On The Barramundi Fishery In Western Australia, N M. Morrissy

Fisheries Research Reports

Barramundi are widely distributed in rivers and estuaries in the semi-tropical and tropical regions of the Indo- Pacific from South China to the Persian Gulf and along the coast of northern Australia. The limiting factors to the distribution appear to be temperature and salinity.


Biological Studies Of Selected Reaches And Tributaries Of The Colorado River, Nelson Thomas, Federal Water Pollution Control Administration Oct 1968

Biological Studies Of Selected Reaches And Tributaries Of The Colorado River, Nelson Thomas, Federal Water Pollution Control Administration

Publications (WR)

This report fulfills the request of the Colorado River Basin Project, Denver, Colorado, to determine the effects of municipal and industrial wastes on the aquatic life in selected waters of the Colorado River Basin. These studies were conducted with the assistance of personnel from the Colorado River Basin Project.


Water Quality Study Of Lake Mead, Dale A. Hoffman, Paul R. Tramutt, Frank C. Heller, Bureau Of Reclamation Nov 1967

Water Quality Study Of Lake Mead, Dale A. Hoffman, Paul R. Tramutt, Frank C. Heller, Bureau Of Reclamation

Publications (WR)

This report presents Lake Mead Water quality data obtained from 1964 to 1966. The effect of filling Lake Powell on the water quality of Lake Mead is evaluated. General limnological principles and the present limnology of Lake Mead are discussed. Lake Mead has a warm monomictic annual temperature cycle characterized by summer stratification, fall overturn leading into a continuous circulation throughout the winter; temperatures never fall below 39 deg F (4 deg C). During stratification, lower dissolved oxygen values were recorded in the thermocline than in the epilimnion and hypolimnion. Mineral content increases from the upper to the lower end …


Development, Verification, And Use Of Methods To Model Chemical And Thermal Processes Lakes Mead And Powell, Bureau Of Reclamation Jul 1966

Development, Verification, And Use Of Methods To Model Chemical And Thermal Processes Lakes Mead And Powell, Bureau Of Reclamation

Publications (WR)

PURPOSE The purpose of the proposed research is to quantify the effects that Lakes Mead and Powell have on the salinity in the Colorado River system, and to evaluate changes that cap be made to the operating system of the reservoirs (within legal/institutional constraints) to enhance salt precipitation and/or minimize evaporation within the reservoirs. The effect of any changes (i.e., selective withdrawal uses, pumped storage, etc.) on reservoir evaporation could also be evaluated with a goal of minimizing evaporation. This will be accomplished through the development of a mathematical model of the reservoirs as described below. BACKGROUND Two major problems …


Fisheries Report No 3 - Western Australian Freshwater Fisheries, Donald D. Francois Jan 1966

Fisheries Report No 3 - Western Australian Freshwater Fisheries, Donald D. Francois

Fisheries Research Reports

Most of the Australian States have a comprehensive system of inland waterways, Western Australia, however, is in a less fortunate position. True, the maps of the State show many rivers, but in much of the southern, more populous part, with no summer rain and no winter snow, the majority are virtually a chain of waterholes during the long summer months. At the same time, in a relatively small section in the south-west corner, there is a series of permanent streams flowing through what was originally dense forest. But apart from the three indigenous freshwater crustaceans, the marron (Cherax tenuimanus), the …


Water Chemistry Survey Of Boulder Basin, Lake Mead, P. R. Tramutt, Bureau Of Reclamation Jun 1965

Water Chemistry Survey Of Boulder Basin, Lake Mead, P. R. Tramutt, Bureau Of Reclamation

Publications (WR)

The survey results indicate that the impoundment of water behind Hoover Dam has not adversely affected the dissolved oxygen (DO) content and that water quality and DO content were uniform regardless of depth. The study made in April-May 1964 will provide water quality data of Lake Mead prior to releases from Lake Powell as a basis for evaluating Lake Powell's effect on water quality and limnology of Lake Mead. The performance of a DO analyzer was tested and found unsatisfactory at depths below 150 ft. Parameters tested by standard chemical analyses of water samples in the Denver Laboratory and by …


Available Water Supply Of The Las Vegas Ground-Water Basin Nevada, Glenn Thomas Malmberg Jan 1965

Available Water Supply Of The Las Vegas Ground-Water Basin Nevada, Glenn Thomas Malmberg

Publications (WR)

The Las Vegas ground-water basin as described in this report includes the southern part of Indian Spring Valley, Three Lakes Valley, the northern half of Ivanpah Valley, and Las Vegas Valley. These valleys in part are inferred to form a hydrologic unit that includes an area of about 3,000 square miles in the southern part of Clark County, Nev.

The valleys forming the Las Vegas ground-water basin are broad structural depressions surrounded by mountains. The climate of the region is arid, and precipitation in the basin lowlands rarely exceeds 5 inches per year. Drainage is interior except for occasional Hood …


Beach Erosion Control Study On Duval County, Fla, U.S. Army Engineer District, Jacksonville Corps Of Engineers Nov 1964

Beach Erosion Control Study On Duval County, Fla, U.S. Army Engineer District, Jacksonville Corps Of Engineers

Waterways and wildlife

The purpose of this study was to define the beach erosion and the hurricane-induced flooding problems in Duval County, to determine the most economical methods of alleviating those problems, and to determine the division of costs between the Federal Government and local interests .


Preliminary Report: Monolayer Behavior Studies, 1959, Bureau Of Reclamation Jan 1960

Preliminary Report: Monolayer Behavior Studies, 1959, Bureau Of Reclamation

Publications (WR)

During the fall of 1959, monolayer behavior studies were made on two lakes in the southwest; Boulder Basin of Lake Mead, Nevada, and Lake Sahuaro near Phoenix, Arizona. These studies were made to evaluate the effect of geographical and climatological conditions on movement and behavior of monolayers. The Lake Sahuaro tests also were used to provide data for design and development of improved methods of application and maintenance of a film on this lake in anticipation of full scale, evaporation-reduction tests to be performed there during the summer of I960. The Lake Mead studies produced the following general points of …


Contour Banks For Filling Dams, B A'B Marsh Jan 1960

Contour Banks For Filling Dams, B A'B Marsh

Journal of the Department of Agriculture, Western Australia, Series 4

A LTHOUGH contour banks have been used in this State for many years to lead water into earth tanks or "dams," it is only comparatively recently that the idea has become really popular.

Thanks to the publicity given to this matter during the last three years many farmers now know that dams may be filled by contour banks, but because they do not know the finer points of the method, they are apt to mislead themselves into thinking that their territory is unsuitable for putting it into practice.


Progress Report On The Ground-Water Resources Of The Las Vegas Artesian Basin, Nevada, George B. Maxey, C. Harry Jameson Mar 1945

Progress Report On The Ground-Water Resources Of The Las Vegas Artesian Basin, Nevada, George B. Maxey, C. Harry Jameson

Publications (WR)

Whether the tremendously increased population acquired by Las Vegas in the years 1940 to 1942 will be retained cannot at present be foretold. However, the valley will undoubtedly be expected to support a considerably larger population than it did at any time prior to 1940, and continually increasing demands on the water supply for innumerable pcacetimc activities must be anticipated. Therefore, a sound evaluation of tho ground water resources of Las Vegas Valley is directly in line with the other wisely progressive planning programs which are now operating or are taking shape in the valley as well as in the …