to follow up on the post on my father’s FBI problems- i thought i would mention that the very same
time of his suspect activities this is what he was working on as well as rockets ! This was work that
followed the disastrous dust bowl period in the USA and its devastation of agriculture- my father
Those particles of the Earth’s land-surface that are in contact with the atmosphere are at the mercy of two powerful natural forces, resulting from water- and air-flow. The story a single soil-grain could tell of its travels would surpass that of Marco Polo. It is unfortunate that one cannot “get the story” and thus answer many questions that are in the minds of those who wish to explain and control its behavior.
The transport of granular material by fluids has been a subject of intense interest, especially in connection with flowing water. A great number of investigations have been made, both in the laboratory and in streams, on the effects of water-erosion and the underlying mechanisms of the movement of debris. As a result, at least for some phases of the process, explanations and empirical rules have been developed.
TRANSACTIONS, AMERICAN GEOPHYSICAL UNION
RECENT DEVELOPMENTS IN THE DYNAMICS OF WIND-EROSION
Those particles of the Earths land-surface that are in contact with the atmosphere are at
the mercy of two powerful natural forces, resulting from water– and air-flow. The story a
single soil-grain could tell of its travels would surpass that of Marco Polo. It Is unfortunate
that one cannot “get the story“ and thus answer many questions that are in the minds of those
who wish to explain and control its behavior.
The transport of granular material by fluids has been a subject of Intense interest, es–
pecially In connection with flowing water, A great number of investigations have been made,
both In the laboratory and in streams, on the effects of water-erosion and the underlying mechan–
isms of the movement of debris. As a result, at least for some phases of the process, explana–
tions and empirical rules have been developed.
When one turns to the problem of the transport of soil by wind, a much less satisfactory
situation is found. Within the last decade, a. pressing need has arisen In the United States far
an understanding of the fundamental principles of wind-erosion due to the severe movement of
soil in the Great Plains region. The phenomenon of the “dust-storm“
has,become familiar, even In the City of Uasnington–2,000 miles distant from the region in which the particles were car–
ried aloft. To the soil conservationist fell the responsibility for developing methods of checking this
destruction of vast areas of valuable land. The necessity of doing something quickly to allevi–
ate a suddenly critical situation brought about an almost “panicky“ search for a solution.
The most obvious way of evaluating proposed control-methods lay In trying them in the
field. A large number of such investigations have been conducted, to determine the defectiveness
of various land-use methods and the effectiveness of corrective measures. Experiments of this
type are of primary importance; however, they are handicapped by dependence on the whim of the
weather, the often objectionable length of time needed to obtain data, and in many instances the
prohibitively large cost. The fact that a control-method recommended in one region may not suc–
ceed in another further restricts the value of the field-studies.
To these difficulties must be added the Inherent complexity of the problem. In Table 1
some of the variables that play a greater or lesser part and some of the surface-effects that
result are listed.
The number of situations that can be set up by making combinations of the variables listed
in Table 1 is seen to be very large. The_ following problems are of basic importance and are,
therefore, the ones upon which research has been concentrated:
(a) The mechanism of lifting the soil from surfaces and the mechanism of transportation and
deposition of particles
(b) The dependence of the amount of soil blown on the velocity and turbulent structure of
(c) The effect of the soil-surface and suspended soli on the velocity-distribution and
structure of wind
(d) The distribution of transported soil-particles above the surface
(e) The effectiveness of obstacles of different kinds In preventing soil-blowing
(f) The mechanism underlying the formation of dunes and drifts, and methods of reclaiming