The impact of cropland conversion on environmental effect in the Loess Plateau : a pilot study based on the national experimentalbases
Bassin-versant ; Biodiversité ; Chine ; Erosion des sols ; Expérimentation ; Formation herbacée ; Forêt ; Propriétés du sol ; Shaanxi ; Sol cultivé ; Utilisation du sol
Biodiversity ; China ; Cultivated land ; Experimentation ; Forest ; Grassland ; Land use ; Shaanxi ; Soil erosion ; Soil properties ; Watershed
The feasibility, methods, and environmental effects of cropland conversion were studied based on 11 typical watersheds of national experimentalbases instead of different geographic areas of the Loess Plateau. The land use change not only decreased
Experimentation ; Research technique ; Runoff ; Threshold ; Turbulence
This technical communication presents some MATLAB routines for visualizing the structure in turbulent signals based on a standard conditional averaging and thresholding approach. The latter information is derived from a wavelet decomposition
of the signal and may assist in providing a process-based explanation of observed flow features.
Les expérimentations de Southard et Mackintosh prouvent uniquement que l'autosuspension n'apparaît pas dans les conditions de test car celles-ci sont basées sur la formule de Bagnold. Un critère de remplacement est proposé ainsi qu'une méthode de
Testing an experimental printing of the Ordnance Survey 1:50.000map
Comparaison entre deux méthodes d'impression de la carte au 1:50000 de l'Ordnance Survey. Un test expérimental, basé sur des critères de lecture de carte, n'a pas montré de différence significative au niveau de la lisibilité des deux cartes.
The weathering of a Late Miocene gypsum-calcareous mudstone outcropping in large badland areas of SE Spain, under a semi-arid Mediterranean climate, was studied by means of 2 experimental approaches using both laboratory and field-based techniques
Discussion sur la structure méthodologique de la géomorphologie| distinction entre les différentes méthodes pour obtenir des données de base| contenu et but des mesures et de l'expérimentation sur le terrain.
on experimental fan-like deposits under conditions of constant water discharge, no base-level change, and no sediment supply. The terrace formation process was investigated by relating terrace morphology to the process of lateral channel shifting accompanied
Base militaire ; Centre d'expérimentation ; Centre nucléaire ; Communauté pluriethnique ; Croissance économique ; Disparité économique ; Economie régionale ; Géographie de l'Océanie ; Métissage ; Océanie ; Polynésie française ; Société ; Vie
Le contexte géopolitique. La formation d'une communauté pluriraciale. Le centre d'expérimentation du Pacifique: l'accroissement des revenus et des déséquilibres. La vie politique.
This article presents a simple physical concept of aeolian dust accumulation, based on the behaviour of the subprocesses of dust deposition and dust erosion. A model is tested in a series of wind tunnel experiments. Some implications of the model
lengths were increased. The runoff data were used to validate a simple process-based model that combines the Philip-two-term infiltration equation with the kinematic wave overland flow principle. The predicted and experimental results agreed well
The A. develops and explores probability-based decision strategies for the consumer spatial search problem. They extend experimental and analytical work in psychology on repeated choice among alternatives. The models encompass a wide range
Channel geometry ; China ; Discharge ; Experimentation ; Fluvial dynamics ; Fluvial erosion ; Fluvial processes ; Human impact ; Model ; Simulation ; Watershed
As a branch of geomorphology, the fluvial dynamic geomorphology is a marginal science among fluid dynamics, sediment mechanics and fluvial geomorphology. With physical modelling by similarity based on Newtonian mechanics, and principle of the same
effect but different structure based on systematic theory, it is possible to study properties, formation and processes in fluvial dynamic geomorphology. A new research method, which is a combination of mathematical simulation by computer with physical
Pour permettre une approche paléoclimatique des formations quaternaires de type périglaciaire, une confrontation des observations détaillées de terrain avec celles effectuées en milieu actif est indispensable. La connaissance des processus de base
permettent de comprendre la dynamique du faciès cryopédologique observé dans un contexte fossile. Mise en évidence de l'utilité de l'expérimentation qui permet de saisir les étapes initiales de l'évolution, difficilement observables en milieu actif.
Canada ; Contrainte de cisaillement ; Cours d'eau ; Eau du sol ; Ecoulement ; Ecoulement fluvial ; Erosion des berges ; Expérimentation ; Lit fluvial ; Mouvement de masse ; Ontario ; Propriétés du sol ; Toronto
Bank erosion ; Canada ; Experimentation ; Mass movement ; Ontario ; River bed ; Runoff ; Shear stress ; Soil properties ; Soil water ; Stream ; Stream flow ; Toronto
The study was based on 2 grey luvisols, a sandy loam and a loamy sand, developed on late Wisconsinan glacial and glaciofluvial deposits near Toronto, Canada. The study involved intensely instrumented flume experiments to identify soil water
Oceanographic and marine mapping: a decade of experience at the Experimental Cartography Unit, London in Monograph 25.
Cartographie thématique ; England ; Experimental Cartographic Unit ; Généralités sur la géographie ; Géologie sous-marine ; Géophysique ; Océanographie ; Recherche ; Royaume-Uni ; Technique cartographique
Expérience depuis 1967| projets cartographiques aboutis ou en cours d'élaboration: le golfe d'Aden, cartographie automatique de la bathymétrie| la bathymétrie de l'Atlantique du NE et constitution d'une base de données à partir des sondages récents
| tracé d'isohypses automatiquement sur des régions-tests| les courants de la mer d'Irlande: film expérimental digital| cartographie géochimique de la Mer du Nord britannique| classification des formes littorales des îles Shetland.
Atacama ; Brouillard ; Chili ; Domaine aride ; Désert ; Expérimentation ; Météorisation ; Sel ; Simulation
Arid area ; Chile ; Desert ; Experimentation ; Fog ; Salt ; Simulation ; Weathering
The AA. investigate interactions within a hyper-arid and hyper-saline weathering environment based on conditions observed in the Atacama Desert. The experimental design produced a matrix of 18 different weathering environments with 6 levels of salt
of breakdown was similar, irrespective of the fog and salt levels. The morphological observations provide an experimental example of the role of inheritance in weathering processes.
Sediment transport rate-based model for rainfall-induced soil erosion
Ecoulement superficiel ; Erosion des sols ; Erosion hydrique ; Expérimentation ; Modèle ; Modèle mathématique ; Précipitation ; Simulation de pluie ; Transport sédimentaire
Experimentation ; Mathematical model ; Model ; Overland flow ; Precipitation ; Rainfall simulation ; Sediment transport ; Soil erosion ; Water erosion
A one-dimensional mathematical model, termed sediment transport rate-based model, is developed for determining rainfall-induced soil erosion and sediment transport. A series of soil flume experiments under simulated rainfall were conducted
to simulate the overland flow and sediment transport and to test the sediment transport rate-based model. The numerically simulated hydrographs, sediment transport rate and concentration distributions are in good agreement with those measured in laboratory
experiments, demonstrating the efficacy of the transport rate-based model.
Aménagement hydraulique ; Capacité de charge ; Ecoulement fluvial ; Expérimentation ; Fluviatile ; Granulométrie ; Gravier ; Lit fluvial ; Modèle ; Niveau de base ; Pente de versant ; Sable
Base level ; Carrying capacity ; Experimentation ; Fluvial processes ; Grain size distribution ; Gravel ; Hydraulic works ; Model ; River bed ; Sand ; Slope gradient ; Stream flow
This paper reports flume experiments with a bimodal gravel/sand bed and sediment feed, designed to investigate river channel response to declining slope. The AA. simulated a series of sites along a concave profile approaching a local base level
and undergoing a transition from gravel to sand bed; it also models the effect of a rise in base level on a fixed site. The results support the view that the gravel-sand transition along river channels with a local base level control is assisted by positive