摘要:

The American Geophysical Union was established in 1919 as the American Committee of the International Union of Geodesy and Geophysics, and its Executive Committee is the Committee on Geophysics of the National Research Council. The objects of the Union are to promote the study of problems concerned with the figure and physics of the Earth, to initiate and coordinate researches which depend upon international and national cooperation, and to provide for their scientific discussion and publication. In the accomplishment of these objects, the Union is divided into Sections following the plan of organization of the International Union of Geodesy and Geophysics. There are now eight Sections, namely, (a) Geodesy, (b) Seismology, (c) Meteorology, (d) Terrestrial Magnetism and Electricity, (e) Oceanography, (f) Volcanology, (g) Hydrology, and (h) Tectonophysics. A Section of Geophysical Chemistry was discontinued May 31, 1924, as the International Union had failed to provide such a Section. The Section of Hydrology was established November 15, 1930—matters pertaining to scientific hydrology referred to the American Geophysical Union had been previously looked after by special committees on Hydrology. The Section of Tectonophysics was established April 9, 1940, for the purpose of promoting and encouraging research of fundamental importance to our knowledge of Earth‐structure not covered in any one of the other Sections of the Un

ISSN:0002-8606    

DOI:10.1029/TR022i001p00003

年代:1941

数据来源: WILEY

摘要:

These three excellent papers present the ground‐water conditions and problems or the San Joaquin Valley from three different points of view. Taken together they comprise a very good picture of the ground‐water resources of the Valley. As the water‐supply problems of the San Joaquin Valley are more acute in the portion of the Valley south of Chowchilla River it is natural that the authors devote more of their discussion to this portion. This should not cause us to lose sight of the fact that a large part of the best development in the Valley is in its northern part where nature has been more liberal in providing an adequate water

ISSN:0002-8606    

DOI:10.1029/TR022i001p00007

年代:1941

数据来源: WILEY

摘要:

General—The San Joaquin Valley is that portion of the great Central Valley of California lying south of the Mokelumne River and the Delta of the San Joaquin River, rising in elevation from sea‐level at Suisun Bay to about 1,000 feet above sea‐level at its southerly border.General geology—The geologic history of the Sierra Nevada and Coast Ranges is determined from the formations exposed over their surfaces and the geologic structure of the mountain blocks. That of the Valley lying between is deduced therefrom as the geologic formations of the mountains are buried beneath later or younger sediments in the Valley. The exact knowledge of subsurface conditions is limited to that revealed through the drilling of water‐wells, the static and pumping water‐levels of these wells, the chemical character of their waters, and in petroleum exploration and we

ISSN:0002-8606    

DOI:10.1029/TR022i001p00008

年代:1941

数据来源: WILEY

摘要:

This paper presents a technical summary of certain hydrologic and hydrographic factors affecting the continued prosperity of the agricultural activities in the upper or southern portion of the San Joaquin Valley in California, with analyses of service water‐requirements and demands upon imported water‐supplies from storage on the San Joaquin River.The data presented herein are from reports of the Division of Water Resources of the State Department of Public Works, Edward Hyatt, State Engineer, and from reports and observations of various public and private agencies and individuals which have collaborated with that Division in the extensive investigations covering the water‐resources of the San Joaquin Valley. Particular reference is made to Bulletin No. 29, San Joaquin River Basin, 1931, a publication of the Division of Water Resources. Since the date of that Bulletin continued field‐investigations and analyses by the Division have been the direct means of pointing out the engineering and economic feasibility of importing regulated water

ISSN:0002-8606    

DOI:10.1029/TR022i001p00020

年代:1941

数据来源: WILEY

摘要:

Drainage‐conditions as we find them today, in the San Joaquin Valley, are largely man‐made. Without attempting to go into detail, or, in fact, even to verify this statement from historical records, it would appear logical to believe that the only primeval need for drainage in the Valley was confined to its flatter portions which were overflowed during the spring and early summer. Our characteristic two‐season climate would limit overflow to periods of heavy rains from January to March and to the first few hot days of early summer when the accumulated snows were melting rapidly. Probably the only permanently swampy areas were the Delta country at the confluence of the San Joaquin and Sacramento rivers where the influence of tidal action was more dominant than the flood‐stage of the streams and the Tulare and Buena Vista Lake areas of Kings and Kern counties. Overflowed areas along the San Joaquin from Mendota to the delta I have not considered as permanently wet as they probably dried up completely during the late summer a

ISSN:0002-8606    

DOI:10.1029/TR022i001p00045

年代:1941

数据来源: WILEY

摘要:

Total evaporation as used in this paper, is the sum of all water‐losses to the atmosphere from a stream drainage‐basin, during the annual climatic cycle. It occurs principally as evaporation from water‐surfaces, moist soil, and snow, as transpiration from vegetation, and as interception. It is quantitatively represented by annual precipitation upon the watershed minus runoff, corrected for change in storage within the watershed and for subsurface leakage. Various terms for this quantity are used in literature such as evapo‐transpiration, fly‐off, natural water‐loss, etc. In view of the growing interest in the determination of water‐losses, hydrologists will doubtless before long unite in selecting a single app

ISSN:0002-8606    

DOI:10.1029/TR022i001p00050-2

年代:1941

数据来源: WILEY

摘要:

Pyramid Lake, in Washoe County, Nevada, is celebrated as a scenic attraction and for generations before the coming of the white man it supplied enormous quantities of fish to the original inhabitants. Indians, from as far distant as Lovelock, gathered on the banks of the Truckee River at the beginning of the first‐high water in the spring, when countless numbers of Pyramid Lake trout and other fish ascended the River to their spawning grounds.Alter the coming of the white man, tons of fine fish were sent yearly to markets in California and Nevada. From all over America sportsmen journeyed to the Lake, and the Pyramid Lake trout, largest known of the species, became famous as a game‐fish. Today, the Lake stands 50 feet below its former normal level. Trie Truckee River enters now through a wide sandy mouth over which few fish can ascend, and very few are now caught in the Lake by sportsmen. However, to the thousands of people who annually visit its shores, Pyramid Lake presents a scene of majestic bea

ISSN:0002-8606    

DOI:10.1029/TR022i001p00071

年代:1941

数据来源: WILEY

摘要:

The purpose of this paper is to discuss briefly some factors of the hydrology in the Sierra Nevada foothills of the San Joaquin Basin. The data presented are primarily concerned with the hydrologic phases of a study started by the Forest Service at North Fork, California, in 1929 to determine the influence of the woodland‐chaparral vegetation on water‐yield, surface‐runoff, and erosion. [A complete discussion of the experimental results of the North Fork study is contained in a manuscript by P. B. Rowe, “influence of woodland‐chaparral vegetation on soil‐water relations,” submitted March 1940 for publication as a U.S. Dept. Agri

ISSN:0002-8606    

DOI:10.1029/TR022i001p00090

年代:1941

数据来源: WILEY

摘要:

In the last session of the meetings of the Section of Hydrology of the American Geophysical Union in Seattle in June, 1940, a resolution recommending that “the expression of normals of precipitation in future hydrologic studies be defined by the median instead of the arithmetical average” was presented. It was moved, seconded, and passed that the resolution be referred to a committee appointed by Chairman J. C. Stevens, composed of P. E. Church (Chairman), Edward L. Wells, and H. P. Boardman. [See p. 1053, Trans. Amer. Geophys. Union, 1940.] The Committee then weighed both the advantages and disadvantages of the median and the arithmetical average and in so doing numerous arguments, both favorable and unfavorable, were brought

ISSN:0002-8606    

DOI:10.1029/TR022i001p00102

年代:1941

数据来源: WILEY

摘要:

There having been no time for the discussion at the Sacramento Meeting, I do not think very many who heard the report got much of an idea of what it was all about. In spite of the fact that I signed it, I do not think it presents a very strong case for the adoption of median in place of average. It seemed, therefore, in order to prepare this brief appendix to the recommendations of the Committee.It seems to me that we should have included a definition of median although perhaps everybody concerned knows what the term means. Taking up the points made in the Committee's report:Under disadvantages of the median(1) The report says, “For certain purposes the arithmetical average is more useful.” The resolution specifies the use of the median only for the “expression of normals of precipitation in future hydraulic studies.” (4) It is not at all necessary to rearrange the data in order to determine the median. The method I use is to assume a trial value and then count the number of items which exceed this value; then if that is greater or less than one‐half the total number of items, adopt another trial value and repeat the operation. It will not take very many trials to determine the median and I think in all cases where a large number of data are involved the time consumed would be less than that required to rearrange the items in the order of magnitude. (6) I was at first under the impression that there was seldom, if ever, a case where there were a number of zeros in the series of numbers. However, if one were attempting to determine the normal precipitation for July or August in the Central Sierra Region over a long period of years, there would doubtless be quite a number of zeros enter into the series since we usually have very little precipitation in those months. Probably in that case the arithmetical mean would

ISSN:0002-8606    

DOI:10.1029/TR022i001p00103

年代:1941

数据来源: WILEY