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Environmental Indicators and Impact Assessment

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Articles 451 - 466 of 466

Full-Text Articles in Fresh Water Studies

An Evaluation Of The Effects Of Dredging Within The Arkansas River Navigation System - Volume Ii - Effects Upon The Phytoplankton Associations, Myra Mcnutt, Richard L. Meyer Jan 1976

An Evaluation Of The Effects Of Dredging Within The Arkansas River Navigation System - Volume Ii - Effects Upon The Phytoplankton Associations, Myra Mcnutt, Richard L. Meyer

Arkansas Water Resources Center Technical Reports

Phytoplankton are a major source of primary production in aquatic ecosystems and constitute one of the most important assemblages of the biotic community. These organisms are the basic level of the trophic pyramid upon which other organisms are dependent. The development, maintenance, and environmental influence of phytoplankton in and on the aquatic ecosystem has been a subject of interest and concern for many years. Most of the studies concerning the nature and distribution of phytoplankton have been confined to lacustrine systems. Hutchinson (1967), citing several lake studies, sutmarized various aspects of the physical and chemical factors associated with phytoplankton. These …


Seasonal And Spatial Variation In Primary Productivity In Boulder Basin, Lake Mead, Clark County, Nevada, Isamu Aoki May 1975

Seasonal And Spatial Variation In Primary Productivity In Boulder Basin, Lake Mead, Clark County, Nevada, Isamu Aoki

Publications (WR)

The 14C light and dark bottle technique for measurement of primary production was utilized as a means of assessing the amount of inorganic carbon being converted Into organic form by the photosynthesis of phytoplankton populations In the Boulder Basin of Lake Mead.

Spatial and time series changes of productivity levels observed at eight sampling locations within Boulder Basin Indicate that the Influence of treated municipal arts' industrial effluent flowing into Les Vegas Bay is contributing high levels of available nutrients at Las Vegas Wash Inlet to cause productivity to approximate those levels associated with polluted waters.

Productivity levels at …


Fisheries Report No 16 - Notes On The Wildlife Of A Proposed Nature Reserve Around Lake Grace And Lake Chinokup, Western Australia, N. L. Mckenzie, W. K. Youngson Jan 1975

Fisheries Report No 16 - Notes On The Wildlife Of A Proposed Nature Reserve Around Lake Grace And Lake Chinokup, Western Australia, N. L. Mckenzie, W. K. Youngson

Fisheries Research Reports

During 1972 and 1973 plants and vertebrate animals were collected and recorded from a proposed 22 000 ha nature reserve centred on a chain of salt lakes in south-western Western Australia (33° 10' S - 33° 35' 8 and 118° 19' B - 118° 29' E).

The dominant plant species were collected, the structural formations desert bed and a vegetation map produced. Seven species of native terrestrial mammal and three species of bat were recorded.

Three of the terrestrial species are endemic to southwestern Western Australia, and two of these - Pseudomys occidentalis and Sminthopsis granulipes - are regarded as …


The Gulf-Atlantic Waterway: Instrument To Increase Profit Margins In The Jacksonville Area, Jacksonville Area Chamber Of Commerce Research Department, Jay A. Smith Jan 1974

The Gulf-Atlantic Waterway: Instrument To Increase Profit Margins In The Jacksonville Area, Jacksonville Area Chamber Of Commerce Research Department, Jay A. Smith

Waterways and wildlife

The purpose of this report is to reassess the economic value that the Gulf-Atlantic Waterway will have on Duval county. This will show the direct relationship on the Port and the indirect benefits to other segments in our economy. This is needed for three reasons: 1. The last economic study was completed by the Corps of Engineers with the assistance of Arthur D. Little, Inc., a national consulting firm, in 1962. So, it has been almost twelve years since an economic report has been started from scratch. 2. The economic reports in the past have been mainly concerned with cost/benefit, …


Phytoplankton Distribution And Water Quality Indices For Lake Mead (Colorado River), Robert D. Staker, Robert W. Hoshaw, Lorne G. Everett Jan 1974

Phytoplankton Distribution And Water Quality Indices For Lake Mead (Colorado River), Robert D. Staker, Robert W. Hoshaw, Lorne G. Everett

Publications (WR)

Phytoplankton samples were collected in Lake Mend 6 times from September 1910 to June 1971 for 8 stations at depths of 0. 3, 5, 10, 20, and 30 m. These samples were processed through a Millipore filter apparatus and 79 planktonic algae were identified. Algal divisions represented were Bacillariophyta, 42 species; Chlorophyta, 18 ; Cyanophyta, 9; Chrysophyta, 3; Cryptophyta, 3; Pyrrophyta, 2; and Euglenophyta, 2. Blue-green algae were dominant in late summer and fall; green algae, diatoms, and, cryptomonads in winter; and green algae in spring. The early summer flora was best represented by the Chlorophyta, Cryptophyta, and Chrysophyta. Palmer's …


A Mathmatical Model Of Primary Productivity And Limnological Patterns In Lake Mead, Lorne G. Everett Sep 1972

A Mathmatical Model Of Primary Productivity And Limnological Patterns In Lake Mead, Lorne G. Everett

Publications (WR)

The temporal and spatial changes in chemical and biological properties of Lake Mead have been investigated, thereby indicating the sources of water pollution and the time of highest pollution potential. Planktonic organisms have been shown to indicate the presence of water problems. Macro- and micro-nutrient analyses have shown that primary productivity is not inhibited by limiting concentrations. A mathematical model has been developed, tested with one set of independent data, and shown worthy of management utility. Although the model works very well for the Lake Mead area, the physical reality of the Multiple Linear Regression equation should be tested on …


A Report On The Condition Of The Gascoyne Catchment, D G. Wilcox, E A. Mckinnon Jan 1972

A Report On The Condition Of The Gascoyne Catchment, D G. Wilcox, E A. Mckinnon

Resource management technical reports

Severe flooding in Carnarvon followed heavy rains on the Gascoyne Catchment in February 1961. The flooding and erosion were extensive enough to suggest that run-off from the catchment was excessive. Lightfoot (1961)* reported that excess run-off was due to degradation of the catchment area. This report will describe the catchment area in terms of the degradation of its rangeland and its susceptibility to erosion.


Report On Water Pollution Problems In Las Vegas Wash And Las Vegas Bay, Environmental Protection Agency Nov 1971

Report On Water Pollution Problems In Las Vegas Wash And Las Vegas Bay, Environmental Protection Agency

Publications (WR)

This report was prepared by the Federal Water- Quality Administration, Pacific Southwest Region, now the Environmental Protection Agency (EPA), Region IX, at the request of the State of Nevada, Department of Health, Welfare, and rehabilitation. In a letter, dated December 5, 1969, this agency asked for technical assistance, as authorized by the Federal Water Pollution Control Act, in developing discharge standards appropriate for Las Vegas Bay, Lake Mead, and the Lower Colorado River. The subsequent study was performed by EPA from January through August, 1970. The establishment of Nevada State Water Quality Standards for these waters will enable responsible officials …


A Conceptual Draft Of A Dynamic Hydro-Biological Model For Lake Mead, L. G. Everett, Bureau Of Reclamation Apr 1971

A Conceptual Draft Of A Dynamic Hydro-Biological Model For Lake Mead, L. G. Everett, Bureau Of Reclamation

Publications (WR)

Food and energy transformation in an aquatic system must be understood in order to develop a simulation approach. This report provides a comprehensive study of an aquatic ecosystem. The objectives of this report are to show: (1) the biological relationships in an aquatic system (2) the role of nutrients in the biological cycle (3) the role of abiotic factors in a limnetic environment (4) the status of the art of "Eutrophication modeling".


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 …


The Effect Of Las Vegas Wash Effluent Upon The Water Quality In Lake Mead, D. A. Hoffman, P. R. Tramutt, F. C. Heller, Bureau Of Reclamation Jan 1971

The Effect Of Las Vegas Wash Effluent Upon The Water Quality In Lake Mead, D. A. Hoffman, P. R. Tramutt, F. C. Heller, Bureau Of Reclamation

Publications (WR)

This study developed from observations made during an earlier study on Lake Mead which was reported in CHE-70, Water Quality Study of Lake Mead. Results from that study indicated that poor-quality water was flowing into the Las Vegas Bay reach of Boulder Basin, Lake Mead. Also reports of deteriorating water quality, resulting in taste and odors in domestic water supplies taken from Boulder Basin as well as a reduction in the attractiveness of Las Vegas Bay for recreational uses caused by aquatic plants and algae blooms, indicated a need for a concentrated study concerning the effects of flows from Las …


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 …


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 …


Interbasin Movement Of Ground Water At The Nevada Test Site, Isaac J. Winograd Mar 1962

Interbasin Movement Of Ground Water At The Nevada Test Site, Isaac J. Winograd

Publications (WR)

The present paper presents hydraulic evidence for the interbasin circulation of ground water through carbonate rocks of Paleozoic age at the Nevada Test Site. An integral part of this evidence is the discovery that aquifers in alluvium and tuff, formerly thought to be the principal aquifers at the Test Site, are semiperched above a thick tuffaceous aquiclude that separates them from the carbonate rocks.

This paper is based on one of the studies being made by the Geological
/="/">Survey for the Atomic Energy Commission. These studies seek to evaluate
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