Erodibility ; Lithology ; Numerical model ; Plant canopy ; Roughness ; Sediment load ; Sediment transport ; Soil erosion ; Suspended load ; Topography ; United States of America ; Water erosion ; Watershed
soil. Available data also indicate that detachment/entrainment thresholds are highly variable in space and time in many landscapes, with local threshold values dependent on vegetation cover, rock-fragment armoring, surface roughness, soil texture
model driven by coarse global databases using an empirical database that covers the conterminous USA. The good agreement between their model results and empirical estimates indicate that the approach presented here captures the essence of agricultural
2012
[b2] Univ. of California, Dept. of Plant Sciences, Davis, Etats-Unis
Aerial photography ; Grassland ; Gully erosion ; KwaZulu-Natal ; Photointerpretation ; Plant colonization ; Soil erosion ; South Africa ; Subtropical zone ; Tree ; Water erosion ; Watershed
1976 and transformed the grassland into a savanna with 9.45% of tree cover in 2009. Gully area increased by 3.9% in the last 64 years and represented 12.76% of catchment area in 2009. A positive correlation between gully retreat rate and Acacia canopy
In this study, flume experiments of flows under a simulated ice cover are presented. Open water conditions and simulated rough ice-covered flows are discussed. Mean flow and turbulent flow statistics were obtained from an Acoustic Doppler
Velocimeter (ADV) above a gravel-bed surface. A central region of faster flow develops in the middle portion of the flow with the addition of a rough cover. The turbulent flow characteristics are unambiguously different when simulated ice covered conditions
are used. Two distinct boundary layers (near the bed and in the vicinity of the ice cover, near the water surface) are clearly identified, each being characterized by high turbulent intensity levels. Detailed profile measurements of Reynolds stresses
and turbulent kinetic energy indicate that the turbulence structure is strongly influenced by the presence of an ice cover and its roughness characteristics.
spread out over Western Alps, also outside the geographical borders of the Region. The high spatial resolution network in combination with satellite devices can be used for an integrated monitoring of snow cover that combines information on snow depth
, amount of snow precipitation and snow cover extension. In particular satellites can provide complementary knowledge on snow cover over large scale with spatial continuity, supplying the lack of data where surface measurements are not available. - (NF)
Interactions between seasonal snow cover, ground surface temperature and topography (Andes of Santiago, Chile, 33.5°S)
Andes ; Chile ; High mountain ; Model ; Periglacial features ; Permafrost ; Sensitivity analysis ; Snow cover ; Soil temperature ; Topography ; Watershed
) on mean GST (MGST) and ground surface thermal regimes. The effect of snow cover onset and disappearance dates on MGST is further examined in a sensitivity analysis. The results corroborate the effect of late snow cover in the linear models, which can
A spatial-temporal modeling approach to reconstructing land-cover change trajectories from multi-temporal satellite imagery
A spatial-temporal modeling approach is developed here for reconstructing land-cover change trajectories from time series of satellite images. The change detection method represents an enhancement to the conventional post-classification comparison
Ohio, the spatial-temporal modeling approach yielded significantly more accurate and consistent trajectories of land-cover change than conventional non-contextual approaches. These results also highlight the utility of spatial-temporal contextual
information in improving the accuracy and consistency of land-cover classifications across space and time.
derived using a 15 m Digital Elevation Model. A supervised classification approach was employed to generate land-cover maps, from which the areas of 3 land-cover classes (agricultural fields, woodlands and forests) were calculated. A post-classification
comparison change-detection technique revealed different trends in land-cover change between the periods 1960–1995 and 1995–2006. Deforestation and cultivation alter the soil hydrological conditions on steep concave slopes, rendering them susceptible
to saturation. This may trigger debris flows during rainfall events. There is a need to restore forest cover on critical slopes.
Development of covered karstic dolines in ground ice environment (Eastern Alps, Austria). Interests of experimental and mathematical modelling
melting phenomena, and based on this they calculated its melting speed. Due to the air circulation in the karst, the lower level of the ground ice starts to melt and the covering sediment particles fall down. Thus the thinned covering sediments will fall
The influence of riparian vegetation cover on diffuse lateral sediment connectivity and biogeomorphic processes in a medium-sized agricultural catchment, Austria
This paper assesses the influence of riparian vegetation cover type on diffuse lateral sediment connectivity on valley floors and investigates biogeomorphic processes acting in forested riparian zones of a medium-sized agricultural catchment
by the respective type of riparian vegetation cover. Forested riparian zones significantly reduce sediment inputs and act as strong disconnectors between the catchment area and the river channel. Topographical features called root dams emerge from biogeomorphic
Air temperature ; Climate ; Debris cover ; Digital elevation model ; Glacial ablation ; Glacial features ; Meltwater ; Moraine ; New Zealand ; Sandur ; South Island
To evaluate the effects of varying debris-cover and climate on ice-melt in a maritime mid-latitude setting, an 11-day ablation stake study was undertaken on ice-cored moraine at Fox Glacier. Ablation rates varied with enhancement of melt-rate under
thin debris-covers. Air temperature from nearby Franz Josef Glacier allowed for a simple degree-day approach to ablation calculations, with regression relationships indicating air temperature is the key climatic control on melt. Digital elevation models
produced from topographic surveys of the ice-cored moraine over the following months indicated that ablation rates progressively decreased over time, probably due to melt-out of englacial debris increasing debris-cover thickness. The morphology
Aim of this paper is the analysis of landscape heterogeneity in different natural conditions by identification of the composition and spatial configuration of CORINE land cover classes on the 2nd classification level. The results of the analysis
deficiency in the cold half-year (21st November – 10th January). Frequencies of occurrence of 10-day periods with full cloud cover or else with less than one hour per day of sunshine were then identified. The analysis involved the formula developed by R
Flow in a tightly curving meander bend: effects of seasonal changes in aquatic macrophyte cover
This study analyses a detailed field data set to provide new insights into primary velocity, secondary flow and shear stress distribution. The study site is a low-gradient peatland meander in north-east Germany, with substantial macrophyte cover
This work aims to ascertain the influence of modifications to land use as well as vegetation cover on the steady-state infiltration rate and associated properties of Andisols on the volcanic island of Tenerife (Canary Islands, Spain). Thirty two
sites were selected in 3 categories of land use/vegetation cover (green forest, pine forest and cropped areas). Infiltration is extremely rapid under green forest but falls considerably under pine forest and in formerly cropped soils. The statistical
the vulnerability of Andisols' soil properties and infiltration to land use modification, while also highlighting the influence of the type of forest cover present.
especially during late spring and summer, and substantially unchanged total precipitation, with marked reduction of snowfall, snow cover, number of snowfall events and duration of continuous snow cover, especially during spring and summer, likely driving
heterogeneity, the results contrast with earlier reported values based on the measurement of pedestal heights and inferred age for deglaciation. The AA. consider that changes in climate and the character and duration of regolith covers to have been important
with surface lowering (thickness and longevity of snow and regolith covers) are identified but as yet cannot be quantified.