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Flume experiments were conducted with five coarse sands of different sizes to investigate the development of bed configurations. For fixed depth and increasing velocity the bed configurations are no movement, flat bed, ripples, bars, and dunes. For sand sizes coarser than about 0.70 mm, ripples are replaced by a flat bed. By introducing an irregularity on the sediment bed, ripples can be initiated in the no-movement and flat-bed phases. Ripples develop because of the effect of turbulence on the bed in the reattachment zone. The resulting strong instantaneous shear stresses initiate a maximum in sediment transport, which generates a ripple. The sequence ripples to bars to dunes observed in the experiments matches that observed in rivers and in the ocean. (Modified author abstract)

This report describes a project in which sandhills (relic dunes) were leveled, and the sand was used to widen the beach against erosion. The project extended from El Segundo to Venice. Water, at high pressure, was shot from nozzles onto the hills. The resulting slurry (sand suspended in water) was sluiced down to a sump or low area. An eductor drew in the slurry by siphon, and discharged it by pipeline to a surge pit. Here, the slurry moved through a surge well to a dredge pump suction. The slurry was then moved by a series of pumps and pipelines to the beach. The report describes the process in detail, shows photos and drawings of the equipment and work, and also shows aerial progress photos of the area. Recommendations are presented about using the method in other areas. (Modified author abstract)

The growth of dune vegetation can be stimulated by the application of suitable fertilizers. Newly planted seedlings and sparse vegetation on the sea dunes can be very much improved by this means, provided the quantity of windblown sand is not excessive. Otherwise sand fences have to be constructed for stabilization purposes. Marram grass and sand twitch can be sown successfully. Marram grass, Baltic marram grass, sand twitch and lyme grass ean be cultivated. With proper fertilization, cuttings can be taken in the autumn from stock planted in the spring. Withered dune grasses can be mown. With proper fertilization a new, vigorous vegetation of suitable height can be obtained. Sand dams and embankments of dredged sand can be sown with a selected seed mixture. Fertilization is recommended. The sand can be stabilized rapidly and satisfactorily by this method. Dykes of drifted sand can be constructed more successfully if a few practical conditions are complied with.

Appartient à l’ensemble documentaire : PhoVerre2

Référence bibliographique : Leroy-Crèvecoeur, 310, Appartient à l’ensemble documentaire : FranceJp0, Couverture

Référence bibliographique : Rol, 43891, Appartient à l’ensemble documentaire : Pho20Rol

Severe sand and dust storms occur at a rate of less than 2 per year on the average in the des ert areas of southwestern United States. Less severe storms average about 4 per year. Most storms occur in late winter or spring and last for a period of 1 to 3 days. Storm incidence is higher in desert areas that have been dis turbed by man's activities, such as agrrgul ture or large- scale military maneuvers. During a storm, sand and dust in militarily significant amounts are carried a few miles at most, but generally only a few hundreds or thousands of feet. Wind-driven sand is carried mostly within 2 feet of the ground, with 6 feet as a maximum height in all but extremely high winds. Critical pick-up velocities of winds vary according to the type of desert surface, the grain size and coherency of the surface materials, and whether or not the surface has been disturbed artifi cially. In dune areas, winds of 10 to 15 miles per hour will innmovement, and on other sandy terrain, winds of 20 miles per hour will be necessary for this. Fine materials on desert flats will be set in motion at 20 to 25 miles per hour, and on alluvial fans and playas at 30 to 35 miles per hh r. No wind-blown mate rial will be derived from desert pavements unless the surface has been broken, and on all other above-mentioned types, disturbing the surface will lower critical pick-up velocities by as much as 5 miles per hour. (Author)

Limited number of copies containing color other than black and white are available until stock is exhausted. Reproductions will be made in black and white only.

Field investigations were conducted in modern beaches, dunes, tidal flats, lagoons, and alluvial fans. Experiments were made also to determine some of the controls in the development of cross-stratification by changing one variable at a time. The angle of repose of sands indicates that both subaerial and subaquerous deposits vary considerably as a result of differences in roundness of grain, sorting, and other textural features. In longitudinal section, the sand deposits in a water tank form series of sloping strata of uniform character which continue to build forward without change in form provided the environmental factors remain constant. Most of the major changes in cross stratification of delta tank deposits which are formed in a standing body of water result from fluctuations in water level. Delta front deposits sectioned transversely to the main direction of movement are essentially horizontal or slightly convex upward where sedimentation has been uniform across a broad surface. Stream erosion and deposition experiments indicate that channels formed by water currents moving over an unconsolidated sand surface tend to have steep sides and flat bottoms.

This is a discussion of an Air Force training film where all scenes are authentic desert. The air to ground terrain scenes were taken over the Sahard south of Wheelus Field, Libya. Some were made well inland, 300 miles from the Mediterranean Coast. All ground scenes of the survival incidents were taken south of Wheelus Field. The sand dunes were photographed in the Arabian Desert of Saudi Arabia. The scenes of desert vegetation and the kangaroo rat were taken in the Great American Desert. The African desert scenes were filmed between 21 May and 3 June 1954. This film is recommended for Briefing for overdesert flights; and Training for desert survival. Intended Audiences are military personnel operating in, near, or over desert areas; Crews and passengers on overdesert flights; and, Ground forces operating beyond an immediate and constant supply of drinking water.

Shock absorbency of various types of ground was tested by dropping impactographs from different heights on a 16-foot drop tower. Results showed that water ahs the greatest shock absorbency of all of the surface materials incuded in this study. However, the problems connected with recovery, and possible damage to items by water itself seriously lessen its value as a drop surface in air drop oeprations. Shallow water tends to reflect the shock absorbency characteristics of its underlying materials. The shock absorbency of a partially compacted sand surface was demonstrated to be approximately 35% less than that of loose dry sand. Moisture in loose sand tends to lessen its shock asborbency by 5g to 40g, depending on the amount present. Dry clay dust is a slightly better shock absorber than loose dry sand. However, deceleration values obtained on compacted dry clay were exceeded only by those on concrete and rock. Both moist dune sand and wet beach sand surfaces have nearly four times greater shock absorbency than concrete or rock surfaces.

The purpose of this report is to describe the biophysical environment of the Georgetown Harbor, South Carolina project area, including all areas that can be expected to be influenced by the operation and maintenance of the project as delimited by the U. S. Army Corps of Engineers, Charleston District Office. Contents: General Setting; Geology; Climate; Soils; Hydrology; Biotic Communities: Open Water, Beach and Dune, Salt Flat, Low Marsh, High Marsh, Brackish Marsh, Freshwater Marsh, Cypress Swamp, Oak-Pine Forest, Agriculture, Man-influenced, Man-dominated; Endangered Species., Includes envelope with chart.

Contents: Quaternary deformation of Western Baja California, Mexico, as Indicated by Marine Terraces and Associated Deposits; Coastal dune systems of Northwest Baja California, Mexico; Coastal salt marshes of Northwest Baja California, Mexico., Also includes Rept. no. TR-O-73-1. See also AD-773 598.

The aim of this study is to explain the dunes and deflation relief formed from sediments accumulated in an ice-dammed lake during the deglaciation in the Kaamasjoki-Kiellajoki river basin. At present the dunes are parabolic fossil dunes formed in periglacial conditions having been deposited by winds blowing from directions lying between WNW and NW. In the subarctic conditions prevailing today eolian activity resulting from the fact that effective wind directions are between W and SW is principally one of deflation. The results of the investigation into the evolution stages of eolian relief are presented in a chronological table in which are also given the periods of vegetation history, the types of vegetation, the climatic conditions and the estimated average July temperatures. (Author)

The author discusses an unusual geographical feature found in the basins of the Vilyuy and Linde Rivers in Yakutiya. The so-called 'Tukulans' are areas of wind-blown sands, with numerous dunes; the latter are dissimilar to barchans in that the 'cusps' are pointed backward. The typical vegetation in such areas is pine and cedar. However, the Tululans are not real deserts, because there are numberous lakes which are situated in deflation basins. Moreover, the general climatic conditions are not those typical for deserts. In addition to being a geographical curiosity, the Tukulans may in some way or another be indicative of the presence of petroleum or gas; however, this latter possibility has not been fully explored. (Author), Trans. of Nauka i Zhizn (USSR) v36 n3 p58-59 1970. Errata sheet inserted.

The formation and existence of coastal sand dunes are important considerations in the analysis of coastal problems and selection and design of remedial measures, but little in the way of detailed information has been published on the coastal dunes of California. This paper describes dune localities along the California coast and examines their common features. Dune forms, beach configuration and conditions, activity of dune sand, and sediment sources are the factors considered in describing the localities.

In connection with its mission of developing hurricane protection plans for the Atlantic and Gulf shores of the United States, the Corps of Engineers, Department of the Army, has need to know the magnitude of shore erosion which can be expected from hurricane wave attack. To partially fill this need, the information on storm wave erosion available in the files of the Beach Erosion Board is summarized in this report.

Storms and increased habitation on barrier islands have reduced the height and width of dunes on the Texas Coast, thereby exposing it to the surges and waves produced by tropical storms in the Gulf of Mexico. This publication reports on experimental means of creating and stabilizing sand dunes to protect the coast. Four locations were selected; the SW end of Galveston Island, Packery Channel, Newport Pass on North Padre Island and Corpus Christi Pass. Low areas of the barrier islands were planted in various types of vegetative cover in an attempt to establish dunes without the aid of sand fences. Snow fencing was used to accumulate windblown sand and vegetative planting made to stabilize dunes. Junk car bodies were placed in line parallel to beaches and used instead of more conventional means to establish and stabilize dunes by trapping sand. Since snow fences are more effective and much cheaper, junk cars are not recommended for building dunes. (Author)

The study appraises the feasibility of photogeologic methods for estimating nature of surface materials, moisture conditions, relief, and other characteristics of desert basin floors in the Saharan region, using medium-scale Tri-Metrogon photography, in black-and-white. A frame of reference is provided by studies on playas in western U. S., by reports on widely-scattered field observations on African basins, and by available literature on regional geology and geography. Interpretation is based partly on direct evidence from what is seen on photos, and partly on indirect evidence deduced from the geologic context. Results are of a reconnaissance nature, informative as to general characteristics, but more limited with respect to specifics because of the scale, type, and quality of the photos. For more definitive interpretation, supplementary sources of data are required. One general conclusion, however, is that the dry, firm type of playa surface well known in western U. S. is uncommon in the Sahara, and has been recognized only in western part of that region. (Author)

Sand ripples in the marine and desert environments were studied so that comparisons of ripple structure, geometry, movement and behavior could be made with theoretical studies. Crest sediment of small wavelength oscillation ripples is slightly coarser than the material in the troughs, whereas for megaripples, trough sediment is coarser. Ripple wavelength is a function of grain size. Sediment motion on the sea floor is negligible when the average surge velocity is less than 10 cm/sec, particle motion commences at 18 to 21 cm/sec and is widespread at 27 to 30 cm/sec. Bedload exceeds 80% of the total load and 95% of all transport occurs within 15 cm of the bottom. In the aeolian environment ripple geometry is variable and wavelength is a function of crest grain size. Using tracer sand it was determined that under winds of 15-25 mph, threshold velocities range from 21 to 36 cm/sec, average grain velocity is 0.78 m/min, natural ripples travel at 0.4 cm/min and the rate of sand transport is about 0.4 metric tons/meter width/hour. (Author), See also report dated Aug 68, AD-681 048.

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Photograph of sand dunes in Death Valley, 1900-1940. The rippled, wind-swept sand dunes are devoid of any vegetation. The sunlight comes in from the right so the left sides of the dunes are dark with shade. Mountains stand across the background.

Photograph of the sky over hills in Death Valley, 1900-1940. Desert hills are visible towards the bottom spanning left to right. Desert bushes and shrubs can be seen on the hills at right, while small clouds cover the entire sky above the hills. Dirt is visible in the foreground.

Photograph of sand dunes at Devil's Playground in the Mojave desert near San Bernardino, 1930. The expanse of large windswept dunes have a rippled surface and are almost completely desolate. A small group of short desert shrubs is tucked into a small valley at right, and there are other plants scattered across the sand. A caption that reads "Devils Play Ground - Mojave Desert" is written at the bottom of the image.

This is a view of sand dunes and palm trees.

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

This is a view of sand dunes and palm trees.

Stereograph with a photograph on one side and a description on the back. The photograph shows a soldier looking over a sand dune to see if an enemy is near., Gelatin silver prints; Stereographs, 9 x 18 cm., Title printed on front of stereograph. Photographer unknown.

The history of dune afforestation in the Netherlands was described in six periods varying in maintenance. Afforestation of dunes in other countries of Europe was reviewed. The origin and evolution of the Dutch dunes were traced, and data were mentioned on the mineralogical and chemical composition of the dune sands. After discussion of other ecological factors those of importance for afforestation were listed as nutrient deficiency, low content of humus and of fine sand, adverse watertable, wide range of soil temperature, the mobility of the sand, windiness, less rainfall than further inland, and damage by rabbits. Further special attention must be paid to local differences in lime content, exposure of slopes and height above the watertable (valleys).Techniques of dune afforestation were discussed: landscaping, soil preparation, drainage, fixation, road making, planting (chiefly Pinus spp.), the differences between the results of direct sowing and of planting out, the protection of forest margins, thinning and exploitation. Plant diseases and damage and some data on cost were discussed.The importance of dune forests (enlargement of the forest area, defence against drifting, wood production and regional social advantage were examined and the most important dune forests were described.

The plant communities on about 1800 ha of dunes were studied before any consequences could be observed of percolation since 1955 of fresh water stored underground for mains supply. Classification was by the French-Swiss and sometimes the Scandinavian sociological system. Some difficulties of classification by the French-Swiss method were discussed. The floristic composition, distribution of the communities and their mutual relations were considered. Chapters cover the broad plant formations, arranged according to succession. New sub-alliances introduced were Erodio-Koelerion albescentis (slightly open dune vegetation on usually limy substrate) and Luzulo-Koelerion albescentis (closed dune grasslands, later in the succession; topsoil often leached of lime).New associations described were Erodium glutinosum-Phleum arenarium- assn. (dune district as far as N. France), Jasione montana var. Litoralis-Phleum arenarium- assn. ( Netherlands and German Friesian Isles), Didymodon recurvirostris - Tortella flavovirens -assn. (small associations mainly of cryptogams on northern faces of limy banks), Ranunculus bulbosus - Trifolium striatum -assn. (moderately grazed or ruderally influenced; completely leached soil; old dunes), (sub-assn. Koeleria albescens on grounds used for drying fishing nets), Hippophaë rhamnoides-Sambucus nigra -assn. and Crataegus monogyna-Betula pubescens -assn.

The area studied was between Egmond and Schoorl (12 km2; 6 km long). Plant associations were described by estimate and by combining the mapsquare method of Clements and the method of Raunkiaer. The dune area was divided into 7 parts, different in vegetation. Towards the south the density of the vegetation and the number of species increased. In each part 7 or 8 plant associations could be distinguished with different watertables. Plant species of only local occurrence were grouped into: A. Northern plants; B. Plants very near the sea; C. Plants of waste places (such as verges); D. Southern plants. The A and D species were calcifuges and calciphils, respectively. The B species were true halophytes, the C and some of the D species were nitrophils.Lime status and pH of soil were closely correlated. The dunes of Bergen were the most acid ones of the Netherlands and differ from the old inner dunes. The lack of some plants and animals on the Friesian islands suggests the former existence of a large post-glacial river between Egmond and Texel. So the dune sands of Bergen are fluvial.

Stiboka onderzoek

RIVON onderzoek zout zoet vegetatie

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

Smudged., This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about

This archival material has been provided for educational purposes. Ball State University Libraries recognizes that some historic items may include offensive content. Our statement regarding objectionable content is available at: https://dmr.bsu.edu/digital/about