This paper focuses on field studies and numericalmodels of fracture development in the area of the Hengill Central Volcano and its northern fissure swarm containing the Thingvellir Graben, in Southwest Iceland. Apart from additional field data
on normal faults, a new detailed map of the Holocene fractures in the Thingvellir Graben is presented and used as a basis for numericalmodels on normal fault development. Results and discussion.
The AA. test the representation of braided channel morphodynamics in the Murray-Paola model, MP model, against the known characteristics (mainly from a sequence of high resolution digital elevation models) of a physical model of a braided stream
. It achieves this by initiating the model from real braided topography rather than white noise. This extension of the application of the MP model is used to identify characteristics that are not reproduced, to investigate their causes, propose modifications
and discuss both the implications for the formation of braiding and alternative modelling strategies.
Numerical investigation into the influence of geometry and construction materials on urban street climate
Applied climatology ; Energy balance ; Microclimate ; Model ; Numericalmodel ; Temperature ; Urban climate ; Urban construction
Bilan énergétique ; Climat urbain ; Climatologie appliquée ; Construction urbaine ; Microclimat ; Modèle ; Modèle numérique ; Température
A numericalmodel is developed for simulating the nocturnal cooling of the ground and walls in typical urban canyons. The model is capable of dealing with homogeneous as well as inhomogeneous (layered) soil and wall substrates. Experiments carried
out with the model show that the differencein the thermal properties of urban asphalt and concrete pavements and the rural surface dry soil substrate could create urban/rural surface temperature differences of up to 4-5K.
This paper uses a time-dependent glaciological model to produce numerical reconstructions of the late Weichselian Svalbard-Barents Sea Ice Sheet, taking account of recent geological, biological, and chronostratigraphic evidence of climatic change
Charge en suspension ; Charge solide ; Cours d'eau ; Erosion des berges ; Géométrie hydraulique ; Modèle numérique ; Méandre ; Simulation ; Transport sédimentaire
The inception of channel meandering is the result of the complex interaction between flow, bed sediment, and bank material. This study presents a two-dimensional numericalmodel that links a physically based bank erosion model with the bend
migration model to simulate the formation process of meandering channels. The model replicates the downstream translation and lateral extension of meandering loops reasonably well.
Satellite images and their use in the numericalmodelling of coastal processes
The interpretation of Landsat imagery of a coastal embayment in the NW Aegean Sea is compared with numericalmodel outputs representing the same environment : remotely sensed data and output from the hydrodynamic and dispersion models can
A hydrodynamic and a dispersion model have been devised. Both models are two-dimensional, vertically integrated, and are solved numerically with a multioperational finite difference scheme (grid 300 300 m). (LW).
The AA. review elements of a structured approach to model development and testing. It is argued that natural breaks in landscape process and morphology define appropriate spatial domains for the study of landscape evolution. The concept of virtual
velocity is used to define appropriate timescales for the study of landscape change. Issues relevant to model implementation, including validation, verification, calibration and confirmation, are discussed. Finally, key developments and characteristics
associated with 3 approaches to the study of landscape modelling : conceptual, quasi-mechanistic and general physics, are reviewed.
This review summarizes and evaluates the important issues concerning numerical surface process models (SPMs) of long-term landscape evolution that have been addressed only in a passing way by previous authors. The issues reviewed here
are : the formulation of the laws that represent fluvial and hillslope processes in SPMs; the implementation of the various algorithms on numerical grids; model parameterization; and model testing.
Numerical framework for geomorphological experiments
Earth surface processes ; Erosion ; Fluvial erosion ; Model ; Numericalmodel ; Sediment transport ; Slope dynamics ; Vertical movement
Dynamique de versant ; Erosion ; Erosion fluviatile ; Géomorphodynamique ; Modèle ; Modèle numérique ; Mouvement vertical ; Transport sédimentaire
In this work the AA. present a numerical framework for simulation of surface processes and landforms. The model is called SIGNUM (Simple Integrated Geomorphological NUmericalModel) 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)
Can better environmental inputs improve sea clutter estimation? A numerical experiment
Expérimentation ; Généralités sur la géographie ; Houle ; Modèle numérique ; Océanologie ; Radar micro-ondes ; Télédétection
Examines the effects of better environmental inputs to a sea clutter model. Outlines and discuss the way of improving the existing sea clutter models. - (CB)
A numericalmodel for shore-normal sediment size variation on a macrotidal beach
Coastal dynamics ; Coastal environment ; Grain size distribution;Granulometry ; Intertidal zone ; Isle of Man ; Model ; Numericalmodel ; United Kingdom
Dynamique littorale ; Granulométrie ; Isle of Man ; Littoral ; Modèle ; Modèle numérique ; Royaume-Uni ; Zone intertidale
This paper describes a computer simulation model which is designed to predict the selective shore-normal sorting of grain sizes in the nearshore environment. The predicted grain size is used in an hydraulic interpretation of grain size distribution
of the intertidal profile, based on the hydrodynamic variations over a tidal cycle on a macrotidal beach. The model is successful in predicting the broad pattern of increasing grain size in the onshore direction which has been observed in nature.
This paper shows the effect of thaw settlement on the thermal response of a small permafrost mound in Northern Québec to different scenarios of climate warming, with a finite-element, one-dimensional, heat conduction model. In addition
permafrost nearer to the surface and accelerates its thawing. It should be included in any numerical simulation.
Chaos ; Model ; North Carolina ; Numericalmodel ; Pedogenesis ; Quaternary ; Soil ; United States
Chaos ; Etats-Unis ; Modèle ; Modèle numérique ; North Carolina ; Pédogenèse ; Quaternaire ; Sol
The purpose of this paper is to explore temporal trends in soil development that might result from various combinations of progressive and regressive pedogenetic pathways via a simple numericalmodel. Implications of the model will be compared
Cours d'eau ; Géométrie hydraulique ; Modèle ; Modèle cellulaire
Channel geometry ; Model ; Stream
This paper outlines the principles of cellular modelling in fluvial geomorphology and addresses issues of model formulation and validation in the context of numericalmodelling more generally. In doing so it seeks to highlight the prospects
for using cellular approaches to develop an improved understanding of both rivers and models.
A computer model along a flow-line of an ice dome: captured ice shelf
Floating ice ; Glacial flow ; Glacier mass balance ; Ice ; Numericalmodel ; Skane ; Sweden
Bilan de masse ; Ecoulement glaciaire ; Glace ; Glace flottante ; Modèle numérique ; Skäne ; Suède
The paper examines the captured ice shelf hypothesis through the construction of a numericalmodel. Based on ice surface elevation, ice thickness, and ground topography, the velocity is calculated. The thickness is adjusted, taking into account
Wildfire disturbance and shallow landsliding in coastal British Columbia over millennial time scales : a numericalmodelling study
British Columbia ; Canada ; Fire ; Landslide ; Model ; Numericalmodel ; Sediment transport ; Slope dynamics ; Watershed
Bassin-versant ; British Columbia ; Canada ; Dynamique de versant ; Feu ; Glissement de terrain ; Modèle ; Modèle numérique ; Transport sédimentaire
An algorithm for wildfire occurrence is introduced for incorporation into a numericalmodel of drainage basin evolution. Within the model, fire return intervals are determined using a stochastic rule set and fire sizes are assigned according
cells in interfluves show a variable response to the inclusion of wildfire in the model.
Numerical simulation of vertical marsh growth and adjustment to accelerated sea-level rise, North Norfolk, UK
Coastal environment ; Coastal marsh ; England ; Eustatism ; Fauna ; Flood ; Flora ; Global change ; Model ; Numericalmodel ; Sea level ; Sedimentation ; United Kingdom
Changement global ; England ; Eustatisme ; Faune ; Flore ; Inondation ; Littoral ; Marais maritime ; Modèle ; Modèle numérique ; Niveau marin ; Royaume-Uni ; Sédimentation
This paper outlines the implementation and application of a refined one-dimensional model designed to simulate the vertical adjustment of marsh surfaces to various combinations of sediment supply, tidal levels and regional subsidence
Apparent thermal diffusivity in soil: estimation from thermal records and suggestions for numericalmodeling
Diffusion thermique ; Géophysique ; Modèle ; Méthodologie ; Propriétés du sol ; Sol ; Suède ; Température ; Température du sol
Geophysics ; Methodology ; Model ; Soil ; Soil properties ; Soil temperature ; Sweden ; Temperature
The concept of apparent thermal diffusivity in soil is discussed and defined as consisting of an intrinsic and a pseudo part. A method that uses a numericalmodel of heat conduction and measured soil temperatures to estimate apparent thermal