Consideration of the available equations for prediction of aeolian sand transport led to the development of a model which relies on optimization techniques for the production of improved performance. The model has been applied
Agropédologie ; Besoin en eau ; Eau ; England ; Evapotranspiration ; Géographie physique ; Modèle ; Norfolk ; Propriété du sol ; Royaume-Uni ; Sol
The supply of water by the soil to meet the transpirational demand of crops, has been modelled on the assumption that water supply is directly related to soil water potential. Results of field testing and discussion.
Rainfall induced soil seal. (A). A critical review of observations and models
Encroûtement ; Géographie physique ; Microstructure ; Modèle ; Propriété du sol ; Précipitation ; Sol
This study is aimed to clear the ground for conceptual modeling of the hydraulic properties of structural soil seals, based on principles of soil physics.
The purpose of this paper is to develop a simple mathematical model of ground flow so as to permit computing the long term steady state flow in rivers as the runoff component of the hydrological cycle.
Using a forest stand simulation model to examine the ecological and climatic significance of the Late-Quaternary pine-spruce pollen zone in Eastern Virginia, U.S.A.
A simulation model of forest dynamics was used to reconstruct the composition and structure of the forests on the Delmarva Peninsula of Virginia, where pollen data were available to test the model, and climate and soils data were available to drive
the model. Reconstructed annual precipitation and summer air temperature were consistent with modern analog estimates from the pollen record.
between modelled and observed values, where the differences are divided by the estimated standard errors of the observed values, is suggested as a diagnostic tool for determining whether random observational errors are significant.
Modelling shore response to sea-level rise on sedimentary coasts
Action anthropique ; Bilan sédimentaire ; Environnement ; Erosion marine ; Géographie physique ; Ligne de rivage ; Littoral ; Modèle ; Niveau marin ; Variation climatique
Analysis of the different approaches which can be used to model the resulting shoreline configuration as a function of sea-level rise. Two approaches are presented and discussed : historical trend analysis and sediment budget approach.
Rainfall induced soil seal. C) A dynamic model with kinetic energy instead of cumulative rainfall as independent variable
Energie cinétique ; Erosion des sols ; Géographie physique ; Infiltration ; Limon ; Modèle ; Propriété du sol ; Précipitation ; Sol
The model is applied in the case of two soils, sandy loam and loam, under saturated conditions. Results and discussion of the observed and predicted infiltration curves.
Dynamic pedogenesis : new views on some key soil concepts, and a model for interpreting Quaternary soils
California ; Concept ; Etats-Unis ; Géographie physique ; Modèle ; Propriété du sol ; Pédogenèse ; Quaternaire ; Sol ; Transverse ranges
A model of pedogenesis is presented in an evolutional paradigm that emphasizes the integrated effects of dynamic and passive pedogenic vectors in directing pathways and in controlling rates of soil genesis through time. This model helps explain
The application of a simple lumped river flow forecasting model to hillslope soil water storage estimation
Bassin-versant ; Cycle de l'eau ; England ; Géographie physique ; Hydrologie ; Modèle ; Prévision ; Royaume-Uni ; Ruissellement
A simple lumped sequential flow forecasting model is applied to a 0.73 km2 catchment, located at Winford near Bristol, and it is shown that if field permeability is available, there is significant potential for the scheme to estimate the mean soil
water storage in catchment segments. In addition, the model is shown to provide reliable river flow forecasting.
Rainfall induced soil seal. (B). Application of a new model to saturated soils
Encroûtement ; Géographie physique ; Limon ; Microstructure ; Modèle ; Propriété du sol ; Précipitation ; Sol
A conceptual model is proposed in which the saturated soil seal (crust) properties are derived on the basis of the physical concepts estimated empirically. The reduced hydraulic conductivity of the soil surface is attributed to its decreased
porosity and increased ineffective water content. The characteristics of the modeled soil seal are examined using data of sandy loam and loam (loess) soils.
A previous model for nearshore orthogonal gradients (Hardisty, 1986) was based upon a simple bedload function and identified feedback relationships between the equilibrium seabed gradient and wave induced flow asymmetry. That model is developed here
The energetic response of urban canyons to variable urban geometry is investigated using the URBAN3 numerical model. Significant inter-urban canyon energy total differences are found which are closely linked to patterns of net solar radiation
. Implications of the study with respect to the magnitude of synoptic vs. geometric sources of urban energetic variation, and microscale and mesoscale urban modelling applications are discussed.
When choosing small basins that are subsets of each other, assumptions of hydrologic and lithologic uniformity may be satisfied. Then the autogenic and allogenic components of the denudation may be calculated by a linear model of uniform mixing
. Results of the model tested in a subartic stripe karst in North Norway and discussion.
The climatology of surface ozone in rural areas : a conceptual model
Action anthropique ; Climatologie ; Dynamique de l'atmosphère ; Environnement ; Espace rural ; Géographie physique ; Modèle ; Ozone ; Pollution ; Type de temps
in synoptic high pressure systems, but also subsynoptic local effects at the mesoscale. A conceptual model of the formation and transport of surface ozone in rural areas is presented, with a brief discussion of promising research approaches and techniques.