摘要:

These records are compiled from various sources. Records from 1841 to about 1850 are from those kept by Dr. Donaldson and his father of Pleasant Valley, a few miles above Davenport. Records from 1851 to 1871 are taken mainly from two sources, namely, C. H. Stoddard of Rock Island, Illinois, and Mr. Robins, Superintendent of the Government bridge at Davenport, Iowa. Some records seem to have been kept at Rock Island Arsenal and Dr. Donaldson also continued his during this time. The records since 1871 are those of the Signal Corps of the United States Army and the weather Bureau. The records have been compared where they parallel each other and preference given to those in agreement. When they show not more than one day's difference, they were considered in agreement since one observer may have observed the phenomena in the afternoon and the other may not have recorded it until next morning when making his river‐observation. Unusually long seasons of closed navigation and those of open navigation were checked with existing records of temperature and other reliable data. Thus the season of 1842–43 with 155 days of closed season was found to be very cold with a late cold spr

ISSN:0002-8606    

DOI:10.1029/TR019i002p00590-2

年代:1938

数据来源: WILEY

摘要:

Records of runoff from lands to oceans and of precipitation on lands are considered to be sufficiently reliable to indicate their relative proportions. It is estimated that for the United States less than 30 per cent of the moisture which falls as precipitation runs off the land and reaches the ocean. It may be argued that the continental moisture is transferred to the ocean only as runoff, and that since the ocean‐levels are constant, less than 30 per cent of the precipitation has a marine origin and the remainder represents reprecipitation from continental evaporation. It may be argued equally well that all of the precipitation is of marine origin, and that, since less than 30 per cent runs off in streams and as underground flow, more than 70 per cent must return to the ocean as water‐vapor. Thus, the disparity between the amount of water which falls upon a continent as rain and that which runs off from it to the ocean is in no sense an indication of the source of the precipitated moist

ISSN:0002-8606    

DOI:10.1029/TR019i002p00595-2

年代:1938

数据来源: WILEY

摘要:

The respective roles of the meteorologist and the hydrologist have, until now, been fairly free of confusing overlaps. The meteorologist has dealt with the atmosphere, including water in the form of vapor which he has handed to the hydrologist as it condensed and fell as rain. The hydrologist, in turn, has undertaken to follow the now widely publicized and graphically ornate “hydrologic cycle” through the return of runoff‐waters to the sea and of evaporated moisture to the atmos

ISSN:0002-8606    

DOI:10.1029/TR019i002p00598

年代:1938

数据来源: WILEY

摘要:

As time marches on, historians are usually quite faithful in recording the activities of man, and it will usually be found that Mother Nature is even more meticulous in reflecting and preserving her experiences, more especially with regard to climate and vegetation. Just how much the activities of man have done to modify the natural conditions of a virgin country may in some respects always remain a question. There is however, no longer the slightest doubt about the influence civilization may have had on the climate—which is none at all! And it is the purpose of the present paper to introduce a few trustworthy witnesses in support of the hypothesis that the activities of man have also been ineffective with respect to noteworthy changes in the general aspect of the native vegetation, outside the ranch‐fences of the W

ISSN:0002-8606    

DOI:10.1029/TR019i002p00604

年代:1938

数据来源: WILEY

摘要:

At San Bernardino, California, a comparison is being made between the transpiration‐loss from a plant, and the total radiant energy received by a horizontal projection of the foliage. It appears likely that the transpiration‐loss can be computed with fair accuracy by the simple procedure of dividing the total radiant energy by the latent heat of water.On the oasis of data taken at Lifton, Idaho, by the Utah Power and Light Company during the summer of 1937, a comparison is being made between the evaporation from Bear Lake, as computed by the energy‐equations, and the numbers obtained by applying a coefficient to the evaporation from a Weather Bureau pan, in accordance with the work done by Rohwer at Fort Collins. The present indications are that the agreement will be decidedly unsatisfa

ISSN:0002-8606    

DOI:10.1029/TR019i002p00607

年代:1938

数据来源: WILEY

摘要:

The instrument herein described was originally designed and built to record the evaporation‐loss from a standard Weather Bureau pan for use in a study of the variation of flow in Santa Ana River. Valuable suggestions were made by various members of the Water Resources Branch of the Geological Survey in Southern California, and financial assistance for construction was given by F. C. Ebert and H. C. Troxell of the same organization. The typing of the paper and some of the drafting were done by Works Progress Administration help.The original instrument was damaged by flood‐waters in 1934, while in operation at Baldwin Park, California. It was then redesigned and constructed of stainless materials and installed on the campus of the San Bernardino Valley Junior College. The Weather Bureau pan was replaced by a thermally insulated pan. The damping unit was added at this time by the present writers. The evaporimeter was placed in regular operation on October 30, 1937, in a study of the relative magnitudes of the various energy‐components associated with solar and sky radiation and with evaporation from water‐surfaces, from damp soil, and from

ISSN:0002-8606    

DOI:10.1029/TR019i002p00609

年代:1938

数据来源: WILEY

摘要:

Early in the course of our studies on water‐relations of soils and plants, it was noted that the amount of water transpired by growing plants was tremendously greater than that evaporated directly from the surface of the soil, and that, under the conditions prevalent in California, evaporation‐losses are too small to warrant concern. These results are based not only on comparison of the losses of water through trees or plants growing in tanks with losses of water from uncropped tanks but also on the results of sampling the soil for moisture‐determinations for fallow and cropped areas in the field.The conclusion that losses of moisture are occasioned by the upward movement of moisture from the lower moist layers of soil and dissipated into the air is based upon the familiar teaching that moisture is capable of moving through the soil in all directions through capillary forces. It is reasoned that the moisture exists in the form of films around the so 11‐particles and in wedge‐shapped masses of water between the soil‐particles at the points of contact with each other, being held partly by the attraction of the non‐water particles for the water and partly by the molecular attraction of the liquid itself. Adjoining particles with different thicknesses of moisture‐films surrounding them hold different amounts of water in the adjacent c

ISSN:0002-8606    

DOI:10.1029/TR019i002p00612

年代:1938

数据来源: WILEY

摘要:

The discussion as to whether forests were the cause of increased rainfall, or whether increased rainfall may possibly be an aid in the production of forests, attracted the attention of the Topographic Service of the United States Government prior to the first trip of the Pony Express. Time has not changed the general subject, but the wording has been modified, and one of the variations of that same subject is the topic of this paper.The United States Geological Survey, since its inception, has been charged with the duty of acquiring and preserving, among other things, data of stream‐flow and allied phenomena. The attempt is here made, first, to assemble data from this source in an attempt to trace the variation of the conception of stream‐flow and its relation to forest‐cover through the records of this branch of the Federal Government, and second, to assemble data from other sources to assist in their evaluation and to present the state of our present knowledge on the su

ISSN:0002-8606    

DOI:10.1029/TR019i002p00619

年代:1938

数据来源: WILEY

摘要:

American foresters have been ardent propagandists and zealots in the cause of watershed‐conservation. Their claims that forests and a mantle of vegetation ameliorate or prevent floods, accelerated erosion and silting of streams and reservoirs have been, however, seriously questioned. For 25 years this controversy has continued, the foresters being charged as extremists with no facts to support their philosophy on watershed‐protection. These contentious discussions chiefly between engineers, meteorologists, and foresters nave produced a voluminous literature; but in spite of this, floods and drouth continue to plague

ISSN:0002-8606    

DOI:10.1029/TR019i002p00629

年代:1938

数据来源: WILEY

摘要:

The plant‐cover on our uncultivated lands varies greatly under different elevations, soil‐types, topography, climatic conditions, and so forth. It is logical, therefore, that we should expect variations in the method of handling surface‐rights on these lands depending on local conditions and that generalization in a regulatory way must be done with care, to avoid more or less serious pitfalls.So also must all interested groups recognize that this cover will be more or less influenced from the impacts made upon it by animal‐life, both vertebrate and invertebrate, wild and domestic. V. E. Shelford [Ecology, v. 12, pp. 455–467, 1931] has attacked the fundamental concepts of some plant‐ecologlsts who apparently consider and name the vegetation apart from the animals. These investigators have desired to learn the ultimate climax of vegetation with the presence of wild animals or with equivalent domestic animals excluded by fencing rather than reduced to the early or origi

ISSN:0002-8606    

DOI:10.1029/TR019i002p00634-2

年代:1938

数据来源: WILEY