Aggregation ; Geostatistics ; Linear regression ; Model ; Simulation ; Spatial autocorrelation
The spatial autocorrelation is modeled using a geostatistical model specified at the scale of the individual. The AA. establish that this approach also is a valid autoregressive model. It is an alternative to the conventional lattice-type approaches
for modeling spatial structure in area-level data.
Forecast ; Hunza river ; Karokoram ; Mathematical model ; Model ; Mountain ; Natural hazards ; Pakistan ; Rockfall ; Slope dynamics
Analyse des principes de conception d’un modèle mathématique tridimensionnel DEBRIS 3D concernant les mouvements des matériaux à éboulement. Ce modèle a été élaboré par l’A. lui-même. Il analyse également les résultats de fonctionnement de son
modèle pour l’éboulement de Karakoram dans la vallée de la rivière Hunza, au Pakistan. Le processus de l’éboulement est décrit par les trajectoires des barycentres des débris qui interagissent entre eux et avec la surface du talweg et subissent en même
The paper generalizes the two-step approach to estimating a first-order spatial autoregressive model with spatial autoregressive disturbances in a cross-section with heteroscedastic innovations.
Dynamique de versant ; Erosion ; Erosion fluviatile ; Géomorphodynamique ; Modèle ; Modèle numérique ; Mouvement vertical ; Transport sédimentaire
Earth surface processes ; Erosion ; Fluvial erosion ; Model ; Numerical model ; Sediment transport ; Slope dynamics ; Vertical movement
In this work the AA. present a numerical framework for simulation of surface processes and landforms. The model is called SIGNUM (Simple Integrated Geomorphological NUmerical Model) and is a Matlab, TIN-based landscape evolution model. The AA. use
the model to show a few examples of simulated topographic surfaces evolved through application of mathematical expressions for hillslope and fluvial erosion, channel sediment transport and surface uplift. Although work in the field of computer simulation
of geomorphological processes of landscape evolution is at its beginning, results and insights from models are gaining more and more attention in the scientific community, justifying and encouraging increasing research efforts. - (NF)
Comparing landscape evolution models with quantitative field data at the millennial time scale in the Belgian loess belt
Bassin-versant ; Belgique ; Dynamique du paysage ; Erosion des sols ; Erosion hydrique ; Etude comparée ; Loess ; Modèle ; Pratique culturale ; Transport sédimentaire
Agricultural practice ; Belgium ; Comparative study ; Landscape dynamics ; Loess ; Model ; Sediment transport ; Soil erosion ; Water erosion ; Watershed
This study compares 3 landscape evolution models and their ability to correctly simulate measured 2 500 year landscape evolution in 2 small catchments in the Belgian loess belt : WATEM LT and LAPSUS as examples of detachment-limited models and WATEM
LTT as an example of transport-limited model. All 3 models are DEM based. Tests demonstrate that a transport-limited approach cannot be used to model long-term landscape evolution in the Belgian loess belt. The difference in performance between
transport-limited and detachment-limited models is clear only when the models are evaluated in a 2D catchment. The lack of such distinction when models were applied in a 1D transect highlights the importance of evaluating landscape evolution models in a 2D
Numerical modelling of combined erosion and weathering of slopes in weak rock
Dynamique de versant ; Erosion ; Géotechnique ; Modèle ; Modèle numérique ; Mouvement de masse ; Météorisation ; Prévision ; Schiste
Erosion ; Forecast ; Geotechnics ; Mass movement ; Model ; Numerical model ; Schist ; Slope dynamics ; Weathering
Due to various decay processes associated with weathering, the stability of artificial slopes in weak rocks may be affected well within their envisaged engineering lifetime. This paper combines two conceptual models for erosion and weathering
, and derives a numerical model which predicts the resulting slope development. This can help to predict the development of a slope profile excavated in a weak rock in time, and can be extended with the addition of strength parameters to the weathering profile
Brazil ; Conceptual model ; Experimental catchment ; Hydrology ; Minas Gerais ; Model ; Tropical zone ; Water resources ; Watershed
The aim of this study was to calibrate and to validate the LAvras Simulation of Hydrology (LASH Model) (Beskow, 2009) in a Brazilian Tropical Watershed for daily streamflow. The Shuffled Complex Evolution (SCE-UA) global search method was used
with the LASH model in order to optimize model parameters that were found to be the most sensitive or not directly measurable. The LASH model was calibrated over a 2-year period. It was possible to conclude that the model has a great potential for being applied
in generating the long-term streamflow as well as flow-duration curves. Therefore, the model can reliably be applied under tropical conditions of this medium-sized watershed or other similar watersheds, thus making it useful to plan the sustainable development
School locations and vacancies : a constrained logit equilibrium model
Choix de l'école ; Comportement des ménages ; Espace urbain ; Etablissement scolaire ; Fonction d'utilité ; Localisation ; Marché éducatif ; Modèle logit
Educational establishment ; Household behaviour ; Location ; Logit model ; School choice ; Urban area ; Utility fonction
Théorie de l'équilibre statique concurrentiel partiel et spécification du modèle logit correspondant sous contrainte pour un scénario donné de politiques (localisations d'équilibre attendues, prix scolaires et choix de l'école. Le test d'exemple est
Accumulation du capital ; Comportement économique ; Croissance économique ; Economie régionale ; Equilibre spatial ; Modèle ; Modèle multirégional ; Système économique
Capital accumulation ; Economic behaviour ; Economic growth ; Economic system ; Model ; Multiregional model ; Regional economy ; Spatial equilibrium
The paper proposes a model of interregional economic growth with travel time, housing, residential distribution, and amenity. The economy consists of multiple regions and each region consists of the CBD and the residential area. The simulation
Application of an S-shaped curve model to the temporal development of tafoni of salt-weathering origin
Aérosol ; Désert ; Etats-Unis ; Japon ; Littoral ; Modèle ; Modèle mathématique ; Météorisation ; Sel ; Taffoni ; Zone intertidale
Aerosol ; Coastal environment ; Desert ; Intertidal zone ; Japan ; Mathematical model ; Model ; Salt ; Taffoni ; United States of America ; Weathering
To describe temporal change in tafone development, an S-shaped curve equation is proposed. The applicability of this model is examined using tafone data selected from seven sites, which are categorized into three different salt-weathering
Internal migration ; Migration model ; Migratory flow ; Multivariate analysis ; Origin-destination ; Regression analysis ; Spatial autocorrelation ; Spatial interaction ; United States of America
Les AA. proposent une technique de filtrage spatial par vecteur propre qui permet de modéliser les réseaux de flux migratoires autocorrelés aux Etats-Unis sur plusieurs périodes. Cette méthode permet d'obtenir deux types de modèles ; un modèle
linéaire ou linéaire généralisé. L'analyse des données migratoires entre états montre que l'incorporation des deux types d'autocorrélation permet d'améliorer le modèle proposé.
Climatic change ; European part of Russia ; Evapotranspiration ; Markov model ; Model ; Precipitation ; Runoff ; Stochastic model ; Stream ; Volga ; Watershed
Le modèle proposé ici est basé sur l’équation stochastique du bilan hydrique du bassin-versant. Les précipitations et l’évaporation de la zone du bassin-versant sont modélisées en appliquant des processus markoviens, non-gaussiens et statistiquement
dépendants. Le modèle proposé peut être utilisé pour l’estimation des variations du régime des précipitations et de l’évaporation liées aux changements climatiques et de leur impact sur les oscillations pluriannuelles de l’écoulement fluvial.
Discharge ; Flood ; Fluvial erosion ; Geotechnics ; Model ; Numerical model ; River bed ; Scouring ; Stream ; Stream flow
A modelling approach is presented to predict local scour under time varying flow conditions. The model is based on a number of hypotheses concerning the characteristics of the flow hydrograph, the temporal evolution of the scour and the geometry
a predictable pattern. Numerical simulations are performed with the same input parameters used in the experimental tests but with no post-simulation calibration. Comparison between the experimental and model results indicates good correspondence, especially
in the rising limb of the flow hydrograph. This suggests that the underlying assumptions used in the modelling approach are appropriate.
Preliminary geosite assessment model (GAM) and its application on Fruška gora mountain, potential geotourism destination of Serbia
Fruška Gora ; Géomorphosite ; Milieu naturel ; Modèle ; Montagne ; Patrimoine naturel ; Potentiel touristique ; Protection des sites ; Serbie ; Vojvodina
Geomorphosite ; Model ; Mountain ; Natural environment ; Natural heritage ; Serbia ; Site preservation ; Tourism potential ; Voivodina
This paper presents a preliminary geosite physical assessment model which has the potential to assist in sustainable planning and the management of natural heritage locations and their transformation into tourism destination. The resultant model
Afrique du Sud ; Bassin-versant ; Free State ; Modèle ; Modèle numérique de terrain ; Réseau de drainage
Digital elevation model ; Drainage network ; Free State ; Model ; South Africa ; Watershed
Data availability is often a serious drawback in the successful modelling of landscapes and geomorphological processes and often researchers have to make do with published data. This paper reports on a suggested methodology to incorporate as many
terrain features as possible into a digital terrain model for a particular central South African landscape. It is shown that by carefully manipulating available data, an accurate presentation of the landscape can be created. - (AJC)
Atmospheric moisture ; Climate ; Climatic change ; Convection ; Global change ; Isotope analysis ; Model ; Precipitation ; Simulation ; Water vapor
Les modèles de climat simulent tous le réchauffement actuel et futur de la planète, mais sont en désaccord sur son amplitude et, plus encore, sur la réponse des précipitations à la hausse des températures. Des mesures satellitaires de la composition
isotopique de la vapeur d'eau à différentes altitudes amélioreraient fortement la représentation des processus nuageux dans ces modèles, surtout en zone intertropicale. – (JPB)
Evaluation of gridded population models using 2001 Northern Ireland Census data
Carroyage ; Distance ; Modèle ; Northern Ireland ; Population ; Royaume-Uni ; Répartition de la population
Distance ; Model ; Northern Ireland ; Population ; Population distribution ; Quadrat mapping ; United Kingdom
The paper assesses the accuracy of models of this type. Population counts for census output areas are reallocated to a 100 m grid and then compared with true population counts uniquely available from the 2001 Census. Kernel width and cell size
are more important than the distance-decay parameter. The spatial scale of input data is more important than model parameters. More attention needs to be given to the varying spatial structures of population between places and incorporating this information
Modèle semi-compensatoire de choix de l'habitat. Les candidats à la mobilité s'engagent dans un processus en deux étapes. La stratégie retient seulement les alternatives qui satisfont les seuils recherchés au niveau des critères. La compensation
intervient pour finaliser le choix. L'estimation révèle les déterminants de la sélection des seuils et du choix du logement. Le modèle s'applique à des contextes de choix comportant un certain nombre d'alternatives.
Immigration ; Induced effect ; Input-output model ; Internal migration ; Interregional migration ; Migratory flow ; Model ; Spain
Les AA. proposent d'utiliser un modèle migratoire multirégional d'entrée-sortie pour mesurer comment l'accueil des immigrés dans une région conduit à déplacer la population parmi toutes les régions incluses dans le modèle. La méthode décrit comment