摘要:

The following is merely a brief statement concerning the probable effect of soil‐moisture conditions in Utah on water‐supply forecasts.In furtherance of our soil‐moisture studies, we have continued to measure the precipitation in the Earth mantle just prior to the beginning of the snow‐accumulation period. This year the measurements were made about the first of November. Unfortunately no precipitation occurred after that date on any of the watersheds until about December 20, with the result that the soil‐moisture determinations showed a much higher moisture‐percentage than was actually present at the time the snow began accumulating on the high

ISSN:0002-8606    

DOI:10.1029/TR021i001p00119-1

年代:1940

数据来源: WILEY

摘要:

Starting with the winter of 1936–37, records have been kept on the penetration of frost under different farming practices, exposures, and cover‐conditions. The data were collected on the Upper Mississippi Valley Soil Conservation Experiment Station farm, located at La Crosse, Wisconsin, which is about 43°5 north latitude. The soil‐types, on which studies were made, are the Clinton Silt Loam which has a four‐ to six‐foot loessial deposit over limestone and the Dubuque Silt Loam, which has a 12‐ to 24‐inch loessial deposit over soil residual to limestone. The measurements of frost‐depth were obtained by the use of a King soil‐tube and hammer. After measuring snow‐depth the tube was driven into the soil‐profile, a few inches at a time. The core‐samples were removed and examined for ice‐crystals. The depth to which these crystals occurred was recorded as the frost‐depth. Three measurements were u

ISSN:0002-8606    

DOI:10.1029/TR021i001p00121

年代:1940

数据来源: WILEY

摘要:

Reports have been rendered periodically telling of the progress made by the Weather Bureau in modernizing its procedures for measuring snowfall in the mountainous areas of the West. These reports have outlined the mountain snowfall‐service from the early days when it was considered adequate to measure depth by a graduated scale, through the early phases in the development of snow‐surveying, to the present‐day station equipped with the shielded storage snow‐gage. Historically, this service has paralleled the development of irrigated areas in the West, beginning before the time when the detailed knowledge of potential water‐supply was considered essential to seasonal planning in irrigation‐operations and before the significance of the water‐content of snow was fully appreciated. Today there is a need for detailed and accurate information regarding the seasonal and areal distribution of snowfall as such affect irrigation and other activities depending upon

ISSN:0002-8606    

DOI:10.1029/TR021i001p00122

年代:1940

数据来源: WILEY

摘要:

The Chairman has announced that I am to discuss problems in forecasting irrigation water‐supplies based upon snow‐surveys. I will, however, discuss informally, and without a prepared presentation, the progress of our snow‐survey and irrigation water‐supply‐forecasting program.As you know, the Appropriation Act of 1935 carried an item in the allotment to the Bureau of Agricultural Engineering to coordinate snow‐surveying, to extend, and, where necessary, to locate and maintain snow‐survey courses. As a result of that appropriation, there was undertaken in the fall of 1935 a program to coordinate snow‐surveying and standardize equipment and methods, and a plan for the exchange of data. That the information might be exchanged, it was essential that the same equipment be used and the same methods of surveying followed in eac

ISSN:0002-8606    

DOI:10.1029/TR021i001p00131

年代:1940

数据来源: WILEY

摘要:

The areas under the jurisdiction of the National Park Service, lying as they do at the headwaters of the important streams as far as water‐supply is concerned, are important from the viewpoint of snow‐surveys.In California, Sequoia and General Grant National Parks, Yosemite National Park, and Lassen Volcanic National Park all lie at the headwaters of streams which are important for irrigation and water‐storage purposes. Crater Lake National Park in Oregon, while not as important from an irrigation standpoint, nevertheless assumes increased importance on account of winter sports. Mt. Rainier National Park in Washington and Olympic National Park in the same State have no particular importance from an irrigation standpoint but are of extreme importance for power‐ and winter‐sport

ISSN:0002-8606    

DOI:10.1029/TR021i001p00134

年代:1940

数据来源: WILEY

摘要:

A progress‐report was made by your Chairman at the Los Angeles and Spokane regional meetings held in December 1938. Twenty‐five attended the Los Angeles meeting and 33 the Spokane meeting, the latter being the first snow‐survey conference in that north region. These were both interesting and profitable meetings, as can be seen by any not able to be present if they read the papers and discussions published last July as Part I of theTransactionsof the American Geophysical Union, 1939.As for several years past, Dr. Church and Carl Elges with their office assistants did most of the work of assembling and preparing these papers for publication and securing the necessary funds for their public

ISSN:0002-8606    

DOI:10.1029/TR021i001p00136

年代:1940

数据来源: WILEY