Soil containing rock fragments: effects on infiltration
Rock fragments in soil: surface dynamics
Infiltration ; Model ; Rock ; Soil ; Soil properties
Procedures for quantifying soil and surface rock fragments are reviewed. Within the soil the physical properties and hydraulic properties that affect infiltration are shown to be influenced by rock fragments. Physical properties discussed are bulk
density, porosity and water content. Hydraulic properties that affect infiltration are water retention, saturated conductivity and unsaturated conductivity. Rock fragments on the soil surface have been reported to both increase or decrease infiltration
Rock fragments in top soils: significance and processes
Rock fragments in soil: surface dynamics
Climatic variation ; Grain size distribution ; Hydrology ; Land use ; Rock ; Soil ; Soil erosion ; Soil properties ; Spatial variation
This introductory paper reviews various aspects of rock fragments in top soils. Such information is required in particular for predicting the impact of climatic or landuse changes on the response of these soils. Particular attention is paid
to the definition and measurement of rock fragment content in top soils, the density of soils containing rock fragments, the spatial distribution and movement of rock fragments in top soils, the effects of rock fragments on some key hydrological processes, thermal
Geomorphogenesis ; Glacial features ; Mountain ; National park ; Periglacial features ; Rock ; Slope ; Slovak Republic ; Structural geomorphology ; Tatra Mountains
Substantial part of the alpine relief of the High Tatra is composed of rock slopes. Geomorphological analysis shows that the development of high rock slopes on crystalline rocks is guided, in principal, by their morphostructural position
Surface sealing as affected by various rock fragment covers in West Africa
Rock fragments in soil: surface dynamics
Africa ; Arid area ; Infiltration ; Model ; Porosity ; Rill wash ; Rock ; Semi-arid area ; Soil ; Soil properties ; West Africa
This paper has two main objectives: to analyse the relations between rock fragment parameters (ground cover, position, size) and sealing for a large range of soils of West Africa which is a region where soils containing rock fragments commonly occur
Rock glaciers in Svalbard. Tentative dating and inferred long-term velocities
Arctic Region ; Cold area ; Dating ; Glacier ; Lichenometry ; Moraine ; Rock glacier ; Slope dynamics ; Spitsbergen ; Svalbard ; Tectonics
A long-term approach based on detailed mapping and lichenometry provides additional information concerning talus-foot rock glaciers overstepping raised beaches in Svalbard. Their regional distribution is primarily controlled by the tectonic pattern
and especially by the network of major thrusting faults. Tentative dating of the start of the rock glaciers movement combined with data on their longitudinal development allowed to infer average long-term rates of rock glacier movement and to compare them
The effect of rock fragment content on fine soil bulk density is investigated and a relation is proposed. Such a relation is an extension of an algorithm that allows the estimate of soil bulk density when rock fragments are not present. A comparison
between measured and predicted data has been made using the equation proposed here and Rawls'algorithm that calculates fine earth bulk density. A nomogram has been constructed for transforming rock fragment content from a by-mass to a by-volume basis
and vice versa. Such a nomogram allows the comparison of data on rock frragment content expressed in different units.
The aim of this study is therefore to identify the factors causing boreholes failures in the crystalline rocks of the basement complex and recommend strategies to overcome these factors.
The relation between surface rock-fragment cover and semiarid hillslope profile morphology
Rock-fragment cover on hillslope surfaces profoundly influences the operation of hydrologic and geomorphic processes on those surfaces. The purpose of this investigation was to examine the spatial variability of rock-fragment cover on morphological
units of hillslopes in southeastern Arizona. Simple statistical models, based upon hillslope gradient as well as a soil-slope factor were developed and validated for the estimation of percent rock-fragment covers on these units.
The effect of rock fragments on wheat biomass production under highly variable moisture conditions in Mediterranean environments
Rock fragments in soil: surface dynamics
Agropedology ; Biomass ; Catena ; Mediterranean area ; Rock ; Slope ; Soil ; Soil properties ; Soil water ; Wheat
The objective of this study was to document the relationships among biomass production of rainfed wheat and those soil properties that affect water availability such as soil depth, rock fragments, parent material and degree of erosion along
Spatial distribution of surface rock fragments along catenas in semiarid Arizona and Nevada, USA
Rock fragments in soil: surface dynamics
Arizona ; Catena ; Forecast ; Model ; Nevada ; Rock ; Semi-arid area ; Slope gradient ; Soil ; Soil erosion ; United States ; Watershed
The major objectives of this study are to determine if a slope gradient-surface rock fragment cover relation exists on various catenas of semiarid Arizona and develop an equation to describe this relation.
Hydric properties of some spanish soils in relation to their rock fragment content: implications for runoff and vegetation
Rock fragments in soil: surface dynamics
Castilla-León ; Grain size distribution ; Rock ; Runoff ; Soil ; Soil properties ; Soil water ; Spain ; Valencia ; Vegetation
This paper examines the influence of rock fragments on the hydric properties of some Spanish soils and, as far as the present knowledge allows, to draw conclusions on the development of vegetation and on the production of surface runoff.
Evidence suggesting that methods of rock-varnish cation-ratio dating are neither comparable nor consistently reliable
Using samples from a prehistoric quarry site in the Mojave Desert, the AA. tested and compared the two principal methods of rock-varnish cation-ratio dating, analysis of rock varnish scrappings and analysis of rock varnish in situ. Discussion
This paper reviews the various effects of rock fragments on soil erosion by water. Since these effects are scale dependent, they are investigated at three different nested spatial scales: the micro-, the meso- and the macroplot. For each scale
the corresponding process mechanism are discussed. Particular attention is paid to the effects of rock fragment cover on the intensity of soil erosion processes. The scatter of the data indicates that a given rock fragment cover can have different efficiencies
Effect of rock fragments on eolian deposition of atmospheric dust
Rock fragments in soil: surface dynamics
Aeolian dust ; Aeolian features ; Experimentation ; Rock ; Spatial variation ; Wind speed
The effect of rock fragment cover on the deposition of airborne dust was examined in a wind tunnel. Four parameters were studied: pebble size, pebble flattening, cover density and wind speed. The effect of these parameters on the deposition of dust
on the pebbles, on the deposition of dust between and underneath the pebbles, and on total dust deposition was measured separately. Air flow separation seems to play a primary role in the spatial distribution of dust deposition within a rock fragment field
Effect of rock fragment eccentricity on eolian deposition of atmospheric dust
The aim of this study is to investigate the physical effects of rock fragment eccentricity on the dust deposition mechanism. This was examined in a wind tunnel. All data in this study refer to intial dust deposition (not accumulation), since only
Flood geomorphology of Arthurs Rock Gulch, Colorado: paleoflood history
The AA. present evidence for multiple late Quaternary paleofloods in Arthurs Rock Gulch, a small ephemeral drainage basin in the Colorado Front Range foothills near Fort Collins, Colorado; and describe their approach to paleoflood retrodiction
Process and age constraints for the formation of Ayers Rock/Australia. An example for two-dimensional mass diffusion with pinned boundaries
Modélisation de la forme de l'inselberg d'Ayers Rock, en Australie centrale pour deux conditions de limites se rapprochant de deux scénarios géologiques possibles d'érosion. Utilisation de corrélations moindres carrés pour comparer les topographies
An experimental approach to the sequence of the stability of rock-forming minerals towards chemical weathering
The aim of this study was to obtain the dissolution rates of common rock-forming minerals in pure and slighly acid aerated water without use of buffers. The use of low pH values appears justified since acid rain as well as biogenic weathering due
Carbonate rock ; Chemical erosion ; England ; Slope ; Soil properties ; United Kingdom ; Weathering
Results from the measurement of microweight loss of Magnesian Limestone rock tablets placed at the soil-bedrock interface on a hillslope over 10 years (1982-1992) gave the same relative pattern of upslope increase in weight loss as did short-term
measurements (1979-1981). Microweighed rock tablets may therefore give unreliable absolute rates and can only be used to indicate relative spatial differences rather than to give reliable data on temporal changes.
Effects of rock fragment size and cover on overland flow hydraulics, local turbulence and sediment yield on an erodible soil surface
The interactions between overland flow hydraulics and sediment yield were studied in flume experiments on erodible soil surfaces covered by rock fragments. The high erodibility of a non-cohesive fine sediment permitted the effects of local
turbulence and scour on sediment yield to be examined. Overland flow hydraulics and sediment yield were compared for experiments with pebble and cobble rock fragment covers. An adjustment of existing scour formulas that predict scour around bridge piers