A note on the verticaldistribution of boulder fields in the archipelago of Åland (Ahvenanmaa)
Champ de blocs ; Distribution spatiale ; Fluvioglaciaire ; Littoral ; Niveau marin ; Périglaciaire ; Suède ; Sédimentaire
Boulder field ; Coastal environment ; Fluvioglacial features ; Periglacial features ; Sea level ; Sedimentary ; Spatial distribution ; Sweden
The distribution of boulder fields situated in three different parishes in Åland is discussed. It has been found that the majority of the boulder fields are situated at altitudes that correspond to Ancylus-transgressions and an early Litorina
Aeolian features ; Aeolian transport ; Experimentation ; Grain size distribution ; Mathematical model ; Methodology ; Wind erosion ; Wind speed
Vertical profiles of the horizontal mass flux of blown sand are investigated experimentally using a passive vertical array in a wind tunnel. This investigation is complemented by the measurements of the longitudinal profiles of mass flux using
a horizontal sand trap. The experiments were conducted with 2 test sands and 5 different stream velocities. A simple equation applicable for both the vertical and the longitudinal sand mass flux variations is introduced and the parameters are estimated from
Chine ; Chine, sud-ouest ; Chongqing, région ; Climat de montagne ; Climatologie ; Couverture végétale ; Distribution spatiale ; Ecosystème ; Gphy ; Géographie physique ; Humidité ; Montagne ; Qinghai-Xizang ; Région naturelle ; Régionalisation
differentiation of the vertical zonation displays a transition from east to west and from south to north corresponding to temperature and moisture distribution. (TNC).
Vertical zonation of the area transition between the Qinghai-Xizang plateau and the Yunnan-Guizhou plateau is based primarily on vegetation cover and soil, modified by considerations of temperature and moisture variations. The regional
There is a recognized need to enhance research of hydraulic, geomorphic and sediment-transport processes in rivers. This research often includes studies of the velocity distribution in rivers. This paper describes the use of the top-setting wading
rod and a table and an analytical expression to more easily obtain vertical velocity profiles in rivers.
Verticaldistribution of grain-size parameters of drifting particles during sand storms in the Taklamakan desert, Central Asia
Aeolian features ; Arid area ; China ; Desert ; Dust storm ; Experimentation ; Grain size distribution ; Sand ; Sedimentology ; Wind speed
The verticaldistributions of grain-size parameters of drifting sand flux during sand storms in the Taklamakan Desert, were investigated through field observation and laboratory wind-tunnel tests. The results show that grain-size parameters
of the drifting sands near the ground surface are similar to those of the source deposits. Regional differences in the verticaldistribution of grain-size compositions are affected by source deposits, wind speeds, and transport rates, but source has more influence
Verticaldistribution of wind-blown sand flux in the surface layer, Taklamakan Desert, Central Asia
The verticaldistribution of the wind-blown sand flux in a 40 cm low layer above the ground surface was investigated through laboratory wind-tunnel tests and field measurements on the mobile dune surface during sand storms in the Taklamakan Desert
. The objectives were: to determine the effect of wind velocity on the distribution pattern of wind-blown sand flow; to examine the properties of the discontinuous function of the transport rate with height; and to develop an equation for expressing the vertical
distribution and predicting the total sediment transport quantity of wind-blown sand flux near the ground surface.
Bibliography ; Biogeography ; Biomass ; Ecosystem ; Forest ; Photogrammetry ; Remote sensing ; Research technique ; Spatial distribution
Laser altimetry or Light Detection And Ranging (LiDAR) technology provides horizontal and vertical information at high spatial resolutions and vertical accuracies. Forest attributes such as canopy height can be directly retrieved from LiDAR data
. Direct retrieval of canopy height provides opportunities to model above-ground biomass and canopy volume. Access to the vertical nature of forest ecosystems also offers new opportunities for enhanced forest monitoring, management and planning.
Spatial distribution of rock fragments in cultivated soils in northern Ethiopia as affected by lateral and vertical displacement processes
Distribution spatiale ; Domaine aride ; Domaine semi-aride ; Désertification ; Ethiopie ; Fragment de roche ; Pente de versant ; Pratique culturale ; Ruissellement ; Sol ; Sol cultivé
Agricultural practice ; Arid area ; Cultivated land ; Desertification ; Ethiopia ; Rill wash ; Semi-arid area ; Slope gradient ; Soil ; Spatial distribution
Although, in semi-arid environments, rock fragments at the soil surface and within the topsoil play an important role in desertification control, little is known about their spatial distribution. Therefore, this study analyses spatial patterns
of rock fragment cover along catenas, and the vertical variations in volumetric rock fragment content in soil profiles in the highlands of Tigray, northern Ethiopia. Natural and anthropogenic processes inducing these patterns are assessed.
Gewinnung von Angaben über die vertikale und horizontale Verteilung der relativen Luftfeuchtigkeit über dem Nordatlantik aus Satellitenaufnahmen in sichtbaren Spektralbereich. (Information on the vertical and horizontal distribution of the relative
3477 vertical humidity distributions measured at 8 ships on the North Atlantic within a period of 2 years were used, together with satellite-based pictures on the visible spectral region, to find out relations for the determination of data
Vertical mixing of gravel over a long flood series
British Columbia ; Canada ; Flood ; Grain size distribution ; Gravel ; Island ; Sediment load ; Sediment transport ; Stream ; Tracer ; Vancouver
and passive grain exchanges throughout most of the bed produce the overall verticaldistribution of marked grains. Gravel exchanges exhibit fairly consistent patterns once tracers are well mixed by large floods. Results highlight the role of flood sequence
Some verticaldistribution patterns of zooplankton of the White Sea determined by the recurrent group
Arctique ; Benthos ; Distribution verticale ; Espèce arctique ; Espèce boréale ; Géographie physique ; Mer Blanche ; Milieu marin ; Plancton ; Taxonomie ; Zooplancton
Etude des distributions verticales de 54 unités taxonomiques de zooplancton de la Mer Blanche à partir de prélèvements effectués entre le 20 juillet et le 1 août 1972 en 51 endroits. A partir de la méthode des groupes récurrents, identification d'un
Author compares three Hungarian key loess profiles on the basis of several parameters. Comparison of the horizontal and verticaldistribution of parameter values aimed at drawing as many sedimentological and paleogeographical conclusions as possible
Composition and size distributions of local and advected sediment trapped over a tidal flat during moderate and storm conditions
Charge en suspension ; Distribution statistique ; Mer de Wadden ; Piège à sédiments ; Slikke ; Sédimentologie ; Taille des grains
Sedimentology ; Slikke ; Statistical distribution ; Suspended load
Les profils verticaux des vitesses de décantation dans une série de pièges piègeant de la matière en suspension dans un micro slikke indique un grand flux vertical de resuspension jusqu'à 1m au-dessus du lit dans des conditions modérées.
This paper describes and interprets the sedimentary facies that can be recognized in the fine-grained deposits of the Boxtel Formation in the Roer Valley Graben and explains the vertical and lateral facies distribution. It is demonstrated