Open Access. Powered by Scholars. Published by Universities.®

Environmental Monitoring Commons

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1771 - 1776 of 1776

Full-Text Articles in Environmental Monitoring

Leaflet No 1003 - The Salt Problem In The Wheat Belt, G. H. Burvill Jan 1950

Leaflet No 1003 - The Salt Problem In The Wheat Belt, G. H. Burvill

Bulletins 1 - 2999

IN the wheat belt of Western Australian bare patches in farm paddocks are often seen. Many are bare, or almost bare, because of too much salt in the soil. The excess of salt prevents the germination of seeds, or kills living plants, because it causes the water supply for germination or growth to be cut off. This salt problem is so serious in places that single farms or groups of farms have been ruined; wheat growing on them has become unprofitable.


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: 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: 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: 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.


Bulletin 115 - The Value Of Windmills For Pumping Water In Western Australia, A. H. Scott Jan 1923

Bulletin 115 - The Value Of Windmills For Pumping Water In Western Australia, A. H. Scott

Bulletins 1 - 2999

It is surprising to note the dearth of up-to-date reliable information dealing with actual results of modern windmills, under working conditions, though literature on thousands of other subjects less important can usually be obtained.

In this bulletin there is presented a complete and accurate record of the amount of water pumped daily by a windmill, under actual working conditions, for a period of 14 months.