Alignment of stone-pavement clasts by unconcentrated overland flow – implications of numerical and physical modelling
Arid area ; Desert ; Experimentation ; Model ; Numerical model ; Overland flow ; Patterned ground ; Stone polygon
Here, the finding of lateral processes contributing to stone-pavement evolution is supported by numerical modelling and physical experiments. These unequivocally show that unconcentrated overland flow can transport clasts to form a closely packed
stone mosaic with characteristics similar to those of natural stone pavements. Monte Carlo runs confirm the natural scatter and allow characterization of the control parameters of clast orientation. The model explains up to 70% of the natural variance
. It is further validated by flume experiments, which confirm model predictions of single object orientation angles. Experiments with multiple objects yield artificial stone pavements with properties similar to those found in the field. However, stone pavements
A tracer study performed on a 3 km long reach of the Danube River in Austria is presented. Forty artificial stones of 3 different sizes were produced and a coded radio acoustic transmitter was implanted. The positions of the stones were observed
are well reproduced by the model. Single tracer stones were transported up to 1000 m during a single flood event. Size-selective behaviour could be shown and the incipient motion of the large 70 mm gravel was detected at lower discharges than predicted
Agricultural land use ; Erosion control ; Ethiopia ; Experiment plot ; Land use ; Rill wash ; Semi-arid area ; Slope gradient ; Stone wall ; Water erosion ; Watershed
to three slope gradients, were established for cropland (cultivated land for annual crop production) and rangeland (heavily grazed land on hillslopes with high rock-fragment cover) at Mayleba catchment in Tigray, Ethiopia. SWC structures tested were stone
bunds, trenches, and stone bunds with trenches, in addition to control plots. In total, 21 large runoff plots (with lengths of 60 to 100 m ) were monitored daily for runoff production and soil loss during the main rainy season (July-September) in 2010
the frost table. However, some ice-wedge signals are obscured or masked by similar hyperbolic reflections produced by stones or active-layer soil wedges. Three-dimensional GPR images ice wedges as linear amplitude anomalies, which excludes the possibility
in experiments : disturbed and uniform bare loess slope in laboratory; natural fallowed soil loess with or without stone covers in field experiments. The aim of this study was to assess the differences in hydraulic parameters and sediment detachment under
Stone-Geary et s’applique à l’ensemble des communes françaises de plus de 50000 habitants à l’exception de Paris. Les résultats montrent que les valeurs minimales des dépenses sont en moyenne de 13% (dans le cadre du système de dépenses non-linéaire) et