摘要:

In the use of snow‐survey data, particularly water‐content measurements, as a basis for estimating or predicting the runoff from a given watershed, it has long been recognized that other factors enter in which disturb the relationship that appears to exist between the amount of water stored in the snow‐blanket at the end of winter and the amount of runoff which occurs during the spring and summer months or runoff‐season.Among the factors which affect the correlation between water‐content and runoff, the following are considered important: (1) precipitation on the watershed during the runoff‐period; (2) evaporation and transpiration‐losses from the watershed, including evaporation or sublimation from the snow‐cover itself; (3) ground‐storage, as reflected by the fluctuations in water‐table caused by draining and recharging of the ground‐water reservoir; and (4) deep percolation‐losses that is, drainage through deep subterranean channels which does not appear again as springs tributary to

ISSN:0002-8606    

DOI:10.1029/TR020i001p00110

年代:1939

数据来源: WILEY

摘要:

In the prediction of spring runoff from precipitation‐records or snow‐surveys, one of the factors which seems to require consideration is the amount of water held in ground‐storage. The determination of the quantity of water in ground‐storage is a difficult problem involving soil‐sampling, measurements of ground‐water wells, and measurements of the flow of small streams and springs. It has occurred to the writer that selected stream‐flow records for either the late fall or early spring might provide a better index of the ground‐water available for spring runoff than that obtained by other methods. This would involve a comparison of runoff in the fall with runoff in the spring, and might eliminate uncertainties in the relation of a reservoir‐level in the fall with runoff in the spring. Such a method would be especially desirable because of the availability of stream‐flow records. The discussion which follows is more an explanation of the method to be used than an attempt to develop an accurate formula for the predicti

ISSN:0002-8606    

DOI:10.1029/TR020i001p00117

年代:1939

数据来源: WILEY

摘要:

Up until now only two periods of the precipitation‐year have generally been considered in relation to snow‐surveys: (1) The accumulative period, broadly speaking, November to March, inclusive: and (2) the runoff‐period April to August or September. It has been pointed out by numerous writers that if the soil beneath the snow‐mantle is dry the melting snow itself will have to reprime the soil before runoff can occur, and this represents a loss to runoff. In arid regions this loss may obviously represent a large percentage of the snow water

ISSN:0002-8606    

DOI:10.1029/TR020i001p00121

年代:1939

数据来源: WILEY

摘要:

This paper is a partial summary of work in part cooperatively conducted by the United States Bureau of Agricultural Engineering, United States Forest Service, Oregon and Colorado Agricultural Experiment stations, and the Works Progress Administration of Oregon. The authors express their appreciation for preparation of the drawings to R. B. Allyn, Jr., Irrigation Engineer, and Gottfried Michaelson.The success of any snow‐survey runoff forecasting program depends in a large measure upon location of the snow‐courses and the regularity and accuracy of the actual field‐measurements. All other things being equal, snow‐courses easily reached are far more desirable than those not so easily reached. As a general rule, however, we believe that accessibility should be subordinated to more fundamental considerations such as freedom from early spring or spotty snow‐melting, undue or irregular drifting, character of soil and vegetal c

ISSN:0002-8606    

DOI:10.1029/TR020i001p00125

年代:1939

数据来源: WILEY

摘要:

A comparison of the relative accuracy of the Mount Rose spring balance as improved by them and the Mount Rose balance (Chatillon type) with iso‐elastic springs was attempted, but the graduations of the two instruments were based on slightly different standards. Therefore, only the graph of the former (Fig. 1) is presente

ISSN:0002-8606    

DOI:10.1029/TR020i001p00135

年代:1939

数据来源: WILEY

摘要:

Chairman BOARDMAN presented his annual report and included with it the financial report. Both are printed above in the proceedings of the Los Angeles Conference [Transactions for 1939, pp. 94–95].A discussion followed, concerning the advisability of formally consolidating the Snow‐Survey Conference with the Section of Hydrology of the American Geophysical Union. Chairman Boardman explained that it was the sentiment of the Los Angeles meeting that the relations between the Snow‐Survey Conference and the American Geophysical Union should continue in an informal way. A motion to endorse the resolution of the Los Angeles meeting for the current year ca

ISSN:0002-8606    

DOI:10.1029/TR020i001p00136

年代:1939

数据来源: WILEY