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Articles 5791 - 5819 of 5819

Full-Text Articles in Environmental Monitoring

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 …


Definite Plan Report On Southern Nevada Water Project, Nevada (First Stage): Project Development Report, U.S. Bureau Of Reclamation Aug 1967

Definite Plan Report On Southern Nevada Water Project, Nevada (First Stage): Project Development Report, U.S. Bureau Of Reclamation

Publications (WR)

This report presents the results of definite plan studies of the Southern Nevada Water Project in Clark County, southeastern Nevada. Construction of this project was authorized under Public Law 89-292 dated October 22, 1965. Authorization of the Southern Nevada Water Project was based on a project plan outlined in the feasibility report of August 1963 as supplemented in April 1965. The definite plan studies have confirmed the general project plan of the 1963 report as supplemented but some important modifications are now contemplated as explained in Part IV.

The project will be constructed in three stages. Stage development is desirable …


Dickey-Lincoln School Lakes, Maine, U.S.A. And Quebec, Canada : Design Memorandum No. 2 Hydrology And Hydraulic Analysis: Section 1 - Climatology And Stream Flow, United States Army Corps Of Engineers, New England Division Jan 1967

Dickey-Lincoln School Lakes, Maine, U.S.A. And Quebec, Canada : Design Memorandum No. 2 Hydrology And Hydraulic Analysis: Section 1 - Climatology And Stream Flow, United States Army Corps Of Engineers, New England Division

Dickey-Lincoln School Lakes Project

This section I is the first of four sections comprising Design Memo-randum No. 2. The other sections are: II - Dickey Dam - Spillway Design Flood, III - Lincoln School Dam - Spillway Design Flood and IV - Flood Analysis and Reservoir Regulation. la section I, hydro-logic studies will be confined generally to the drainage area of the Saint John River above the gaging station at Fort Kent, Maine. The purpose of section I is to present the climatological and streamflow data for the Saint John River above Fort Kent in order to establish hydrologic criteria for the design of …


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 …


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 …


How To Measure The Capacity Of Farm Dams, G Gauntlett Jan 1965

How To Measure The Capacity Of Farm Dams, G Gauntlett

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

AT some time or another nearly every farmer needs to be able to measure the capacity of an ordinary farm dam of the "excavated earth tank" type and many requests are made for a method of calculating this volume.

This article describes how this can be done.


Ground-Water Appraisal Of The Meadow Valley Area, Lincoln And Clark Counties, Nevada, F. Eugene Rush Jul 1964

Ground-Water Appraisal Of The Meadow Valley Area, Lincoln And Clark Counties, Nevada, F. Eugene Rush

Publications (WR)

This report, the 27th in the series of reconnaissance ground-water studies which were initiated following authorization by the I960 Legislature, gives the results of a study of the Meadow Valley area. This area includes eight valleys in southeastern Nevada - - Patterson, Spring, Eagle, Dry, Rose, Panaca, Clover, and Lower Meadow Valley - - all part of the Colorado River drainage system.

This study was made and report prepared by F. Eugene Rush, Geologist for the U. S. Geological Survey.

These reconnaissance ground-water resources surveys make available pertinent information of great and immediate value to many State and Federal agencies. …


Salt Land Survey, 1962 : Report Of A Survey Of Soil Salinity In The Agricultural Areas Of Western Australia, L C. Lightfoot, S. T. Smith, C. V. Malcolm Jan 1964

Salt Land Survey, 1962 : Report Of A Survey Of Soil Salinity In The Agricultural Areas Of Western Australia, L C. Lightfoot, S. T. Smith, C. V. Malcolm

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

IN Western Australia there are within the agricultural areas about one million acres of salt land, largely within the 14-25 inch rainfall area used for cereal and wool production.

In March, 1962, farmers in 68 shires in the agricultural areas of Western Australia estimated that on their properties 305,270 acres of land previously cropped or sown to pasture had become salt affected. Of this total, 59,203 acres had gone salt in the seven years immediately before the survey.


Development Of Water Quality Criteria For Aquatic Life, Clarence M. Tarzwell Nov 1962

Development Of Water Quality Criteria For Aquatic Life, Clarence M. Tarzwell

United States Environmental Protection Agency: Staff Publications

It is now recognized that water pollution is an important problem, that it becomes more widespread and serious as population and industry expand, and that something must be done if aquatic life resource are to be saved and their productivity maintained. In the past there has been a great deal of uncertainty in approaching this situation and a general lack of understanding of the details and ramification of the overall problem. In the efforts for the abatement of pollution, only a few clearcut objectives have been established. Knowledge is lacking as to what the objectives should be. There is still …


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
the risk that may arise if ground water should be contaminated …


Fossils And Farmers. 2. The Ice Age, D Merrilees Jan 1961

Fossils And Farmers. 2. The Ice Age, D Merrilees

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

What did the giant Australian marsupials of the "Ice Age" look like?

Fossil remains found by farmers could help reconstruct them, as well as giving some idea of conditions on the Australian continent at that time, says D. Merrilees, B.Sc, acting Curator of Palaeontology at the West Australian Museum.


Fossils And Farmers, D Merrilees Jan 1961

Fossils And Farmers, D Merrilees

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

The West Australian Museum is looking for fossil remains from the Pleistocene age, the period of geological time when Europe was covered with ice.

Little is known of what the Australian continent was like at that time, and the Museum hopes, by collecting as many fossil remains as possible, to get a better picture of Australian conditions at that time.

It is also hoped to discover more about the ancestors of our present marsupial fauna.

Farmers may be able to make a valuable contribution to the present knowledge of this period by forwarding suspected fossil remains to the Museum. Here …


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 …


Comprehensive Survey Of Sedimentation In Lake Mead, 1948-49, W. O. Smith, C. P. Vetter, G. B. Cummings, U.S. Bureau Of Reclamation Jan 1960

Comprehensive Survey Of Sedimentation In Lake Mead, 1948-49, W. O. Smith, C. P. Vetter, G. B. Cummings, U.S. Bureau Of Reclamation

Publications (WR)

Reservoirs are becoming an increasingly prominent feature of the American landscape. Built for flood mitigation and to change a fluctuating river into a dependable source of water for irrigation, power, and other purposes, they are predestined, like natural lakes, to be destroyed sometime following their creation. Sedimentation sooner or later robs most lakes and reservoirs of their capacity to store water. The significance of sedimentation in the life of Lake Mead, the largest artificial reservoir in the world, was realized when the plan for the reservoir was conceived, and an aerial survey of the floor was made in 1935 before …


Weed Research. 7. Weed Control Around The Yard, Geoffrey A. Pearce Jan 1960

Weed Research. 7. Weed Control Around The Yard, Geoffrey A. Pearce

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

MANY farmers and city householders have weed problems around houses and sheds which can be readily overcome by treatment with appropriate herbicides.

The risk from fire through weeds and unslightly growth can easily be removed and an area free of any plant growth can be maintained with little effort for a considerable period.


Industrial Wastes: Bio-Assays For Control Of Industrial Effluents, Croswell Henderson, Clarence M. Tarzwell Sep 1957

Industrial Wastes: Bio-Assays For Control Of Industrial Effluents, Croswell Henderson, Clarence M. Tarzwell

United States Environmental Protection Agency: Staff Publications

Waste effluents from many industries are toxic to fish and other aquatic life. The control or treatment of these wastes for safe release into receiving waters presents a problem of consider able magnitude.

Much effort has been expended by some industries to solve this problem, primarily through chemical analysis for possible toxic components and then generally by a search of the literature to find out how toxic a particular component may be. Unfortunately, this approach has not been successful, nor can it be expected to be productive of satisfactory answers.


Stream Pollution- Aquatic Macro-Invertebrate Communities As Indicators Of Organic Pollution In Lytle Creek, Arden R. Gaufin, Clarence M. Tarzwell Jul 1956

Stream Pollution- Aquatic Macro-Invertebrate Communities As Indicators Of Organic Pollution In Lytle Creek, Arden R. Gaufin, Clarence M. Tarzwell

United States Environmental Protection Agency: Staff Publications

Year-round field studies of the com position and ecology of stream communities associated with the purification of organic wastes in streams were initiated on Lytle Creek in October, 1949. This creek, which is located about 45 miles northeast of Cincinnati, Ohio, is a tributary of the Little Miami River. Its drainage basin comprises 27 sq. mi., a third of which is contained within the city limits of Wilmington, Ohio, a city of some 7,412 persons


Industrial Wastes, Charles E. Renn Mar 1955

Industrial Wastes, Charles E. Renn

United States Environmental Protection Agency: Staff Publications

This paper presents a summary of experiences with a variety of cyanogenic wastes. The work has attempted to evaluate the interaction of waste bearing waters and the environment in terms of waste disposal design requirements. In this, the approach is somewhat more critical than that commonly taken by fisheries biologists, conservationists, and others who have been concerned with the "preventive" aspects of waste disposal.

The first phases of the work were designed to discover the tolerable limits of certain waste components to fresh water fish. This was undertaken in 1950; in the interval the composition of the wastes has been …


Stream Pollution, Ruth Patrick Feb 1953

Stream Pollution, Ruth Patrick

United States Environmental Protection Agency: Staff Publications

This paper discusses the various ways in which aquatic organisms may be of use in solving problems associated with waste disposal. Since many state and federal laws set forth that nothing may be discharged that is deleterious to aquatic life, the most expedient way to determine the effect of an effluent is to study the aquatic organisms themselves.

In every river that has not been adversely affected by pollution there is a great variety of aquatic life. These organisms do not represent a great mass of living things, but rather they are organized into an intricately balance systems, often referred …


It's Time To Take Stock Apr 1950

It's Time To Take Stock

United States Environmental Protection Agency: Staff Publications

Likening colleges and universities to the automobile industry may seem far-fetched, but is it? Each is engaged in fashioning and selling necessary products- one trained men, the other mechanical equipment. Both entered the post-war years with production at low ebb; unable to satisfy pent-up customer demands. Time and high-speed assembly lines have bridged the gap of gas buggy shortage. The impact of selective buying by a discriminating public is now real cause for concern among some of the motor moguls. Rumor has had it that schools teaching wildlife management are overproducing. We decided to gather facts and opinions at the …


Public Health Reports, Clarence M. Tarzwell Feb 1950

Public Health Reports, Clarence M. Tarzwell

United States Environmental Protection Agency: Staff Publications

Preliminary tests with DDT for the control of mosquitoes, forest insects, and agricultural pests demonstrated that it was toxic to a wide variety of animal life. Because there were indications that the new insecticide would be widely used, apprehension was expressed by some groups that its extensive or indiscriminate use would cause extensive harm to wildlife.

The desirability of carefully controlled use was early recognized by those in charge of extensive programs for the control of insects of public health importance. A joint statement of policy for the use of DDT issued early in 1945 (1) by the Army and …


Geological Survey Circular 346: First Fourteen Years Of Lake Mead, Harold E. Thomas Jan 1949

Geological Survey Circular 346: First Fourteen Years Of Lake Mead, Harold E. Thomas

Publications (WR)

This circular summarizes the results of recent studies of Lake Mead and its environs. Area-capacity tables, prepared on the basis of a hydrographic survey of the lake in 1948-49, show that the capacity of the reservoir was reduced 4. 9 percent during the first 14 years after Hoover Dam was completed, but the usable capacity was reduced only 3.2 percent. Practically all of this reduction was caused by accumulation of sediment in the reservoir. Studies of inflow and outflow indicate that the reservoir has a total storage capacity about 12 percent greater than that shown by the area-capacity table, because …


Observations On The Nighttime Resting And Biting Habits Of Anopheline Mosquitoes In Ddt-Treated And-Untreated Buildings, Clarence M. Tarzwell, Frank W. Fisk Jan 1947

Observations On The Nighttime Resting And Biting Habits Of Anopheline Mosquitoes In Ddt-Treated And-Untreated Buildings, Clarence M. Tarzwell, Frank W. Fisk

United States Environmental Protection Agency: Staff Publications

Laboratory cage tests and controlled experiments in houses have clearly demonstrated that residual-spray deposits of DDT are lethal to mosquitoes for considerable periods. Although these tests valuable information on the durability of DDT residual deposits, they did not give information on the mortality of malaria mosquitoes naturally entering treated dwellings in search of a blood meal. In order to secure a lethal dose of DDT from residual deposits, mosquitoes must actually touch the material and be exposed to it for a considerable period. This period has been shown to vary (1), depending on the temperature, age of treatment, density and …


Water Levels And Artesian Pressure In Wells In Las Vegas Valley And In Other Valleys In Nevada, 1913-1945, T. W. Robinson, George B. Maxey, J. C. Fredericks, C. Harry Jameson Jan 1947

Water Levels And Artesian Pressure In Wells In Las Vegas Valley And In Other Valleys In Nevada, 1913-1945, T. W. Robinson, George B. Maxey, J. C. Fredericks, C. Harry Jameson

Publications (WR)

The rock formations of the earth are great natural reservoirs in which a part of the water derived from rain and snow is stored. Water levels and artesian pressure in wells register the stages of these natural reservoirs. The changes in water levels or artesian pressure are indicative of the depletion or replenishment of the natural reservoirs. Systematic and periodic measurements of water levels and artesian pressure in wells have been made in Nevada, by State and Federal agencies from time to time. However, only a few of these measurements have ever been published. Under the cooperative arrangement between the …


The Feeding Habits Of Gambusia Affinis Affinis, With Special Reference To The Malaria Mosquito, Anopheles Quadrimaculatus, A.D. Hess, Clarence M. Tarzwell Jun 1941

The Feeding Habits Of Gambusia Affinis Affinis, With Special Reference To The Malaria Mosquito, Anopheles Quadrimaculatus, A.D. Hess, Clarence M. Tarzwell

United States Environmental Protection Agency: Staff Publications

The viviparous top minnow, Gambusia affinis affinis (Baird and Girard), has for many years been considered an important predator of the immature stages of mosquitoes. Various field workers have reported on the value of this species in controlling both anopheline and culicine mosquitoes, but few detailed studies have been made. Probably the most detailed of these has been that of Hildebrand (1925). His investigations were made during the summers of 1921-24 in the vicinity of Augusta, Ga., with the subspecies G. affinis holbrooki. Employing the common dipper method, he compared the densities of anopheline and culicine larvae and pupae in …


An Analysis Of Fishing In The Tva Impoundments During 1939, R. William Eschmeyer, Clarence M. Tarzwell Jan 1941

An Analysis Of Fishing In The Tva Impoundments During 1939, R. William Eschmeyer, Clarence M. Tarzwell

United States Environmental Protection Agency: Staff Publications

An inventory of fishing on Norris, a storage reservoir, was begun in 1938. The following year it was extended to Wheeler, a run-of-the-river reservoir, and to the tailwater area below Wilson Dam. This inventory, therefore, covered each of the three general types of fish habitats created by the TVA dams. This discussion is a summary of the 1939 fishing data, together with recommendations for fish management based on the creel census information. The data collected totaled 34,270 usable fishing records, representing a catch of 98,495 fishes.


Examination Of Water Supply Of Indianapolis, Alonzo S. Roberts May 1897

Examination Of Water Supply Of Indianapolis, Alonzo S. Roberts

Manuscript Thesis Collection

An assessment of municipal and well water supplies of Indianapolis in 1897.


Cercidiphyllum Japonicum (Katsura) Id, Caidan Zhuoma Apr 202

Cercidiphyllum Japonicum (Katsura) Id, Caidan Zhuoma

BIO 140 Arboretum Project

Location: Between O'Hare and McKillop