Algorithm ; Biogeography ; Comparative study ; Conceptual model ; Ecological niche ; Model ; Plant species ; Simulation ; Spatial distribution ; Statistical analysis
This progress report addresses virtual species distribution models : the use of spatially explicit simulated data to represent a true species distribution in order to evaluate aspects of model conceptualization and implementation. Simulating a true
species distribution, or a virtual species distribution, and systematically testing how these aspects affect SDMs, can provide an important baseline and generate new insights into how these issues affect model outcomes.
Micro-simulation models have been increasingly used for studying various urban and regional processes. Here, two experimental microsimulation models are applied to the study of residential location choices of inhabitants of the Tábor micro-region
. The ability of the micro-simulation models to replicate the observed residential choices is evaluated by several quantitative indicators with special attention given to the stochasticity of the model behaviour. The limited availability of sufficiently
disaggregated data describing the demographics of households, their socio-economic characteristics, and real estate market dynamics needs to be resolved in order to exploit the full potential of micro-simulation modelling in the future. - (EN)
Agriculture ; Evolution de versant ; Modèle ; Modèle numérique de terrain ; Rendement agricole ; Tchèque république ; Topographie
Agriculture ; Crop yield ; Czech Republic ; Digital elevation model ; Model ; Slope evolution ; Topography
This paper deals with the prospects of modelling topographic features – digital elevation models and slope models for an experimental plot with an area of 11.5 hectares. The basis for the creation of these models is formed by data from various
sources (combine yield monitor, RTK-GPS and data from airborne laser scanning). The models of topographical characteristics were compared with crop yields during the observed period of 2004–2012, in order to determine which data source is best
Comparative study ; Digital elevation model ; Erosion rate ; LiDAR ; Model ; Norway ; Soil erosion ; Water erosion ; Watershed
The Limburg Soil Erosion Model (LISEM) and the EROSION 3D model were applied to the Skuterud catchment in the Ås municipality, for which measured discharge data, at the outlet, was available. The goal of this study was to investigate how
the differences of two physically based models will influence the result of one and the same problem, to give an in-depth insight of what are the sources of uncertainty in modelling processes. Special attention was given to the dependency of the model results
on effects of grid cell size and time resolution. The grid cell size of the maps was easily adapted by using digital elevation models (DEM) obtained from airborne light detection and ranging (LIDAR) data. Furthermore the predicted erosion patterns were
compared with an orthographic picture to validate the simulation results also in a spatial context. With both models, it was possible to simulate a satisfactory accurate hydrograph and total amount of surface discharge. However, the output maps produced
by the models showed quite different erosion and deposition features.
Africa ; Conceptual model ; Lateglacial ; Model ; Numerical model ; Palaeo-environment ; Palaeoclimate ; Pleistocene ; Precipitation ; Quaternary ; Simulation ; Southern Africa ; Temperature
half a century of research in southern Africa : (1) a brief historical review of key conceptual models is given, (2) key points of conflict that emerge in synthesis of palaeoenvironmental proxy records are outlined and (3) numerical model simulations
Global sensitivity analysis of a large agent-based model of spatial opinion exchange : a heterogeneous multi-GPU acceleration approach
Analyse de résolution de problèmes ; Analyse de susceptibilité ; Analyse de variance ; Analyse spatiale ; Echange d'opinions ; Modèle ; Modèle agent ; Unité de traitement graphique multiple
Analysis of variance ; Model ; Spatial analysis
The objective focuses on the sensitivity analysis of large agent-based modeling of spatial opinion exchange, accelerated using multiple graphics processing units (GPUs). It is conducted using a variance-based approach, requiring numerous model runs
for Monte Carlo integration. Experimental results indicate GPU-accelerated general-purpose computation provides an efficacious and feasible solution for the sensitivity analysis of large agent-based models. The heterogeneous parallel computing approach
Channel geometry ; Downcutting ; Fluvial dynamics ; Knickpoint ; Longitudinal section ; Model ; Stochastic model ; Stream
The stream power incision model (SPIM) is a cornerstone of quantitative geomorphology. It states that river incision rate is the product of drainage area and channel slope raised to the power exponents m and n, respectively. It is widely used
to predict patterns of deformation from channel long profile inversion or to model knickpoint migration and landscape evolution. Numerous studies have attempted to test its applicability with mixed results prompting the question of its validity. This paper
Entropy ; Estimation ; Household ; Methodology ; Model ; Modelling ; Population ; Spatial analysis ; Spatial distribution ; Tennessee ; Uncertainty ; United States of America
This article presents a new dasymetric methodology—the penalized maximum entropy dasymetric model that enables sources of uncertainty to be represented and modeled. It allows a rich array of data to be included, with disparate spatial resolutions
In this paper, we use an interregional computable general equilibrium model for Lebanon—the ARZ model—for the analysis of place-based policies in the country, in an attempt to bring additional insights to some of the proposals presented
in the National Physical Master Plan of the Lebanese Territory. We apply the model to look at the ex ante potential regional implications of an increase in domestic and international integration of Lebanese regions through reductions in trade costs. The link
Modeling soil erosion and river sediment yield for an intermountain drainage basin of the Central Apennines, Italy
Appennino ; Bassin-versant ; Bilan sédimentaire ; Erodabilité ; Erosion des sols ; Erosion hydrique ; Italie ; Lazio ; Modèle ; Prévision ; Système d'information géographique ; Variation spatiale
Appennino ; Erodibility ; Forecast ; Geographical information system ; Italy ; Lazio ; Model ; Sediment budget ; Soil erosion ; Spatial variation ; Water erosion ; Watershed
The AA. focused on accelerated soil erosion processes in an Italian central Apennine intermountain watershed using modeling techniques implemented in a GIS environment. They proposed an integrated modeling approach applying a RUSLE model
and a Turbidity Unit (TU) Index. The model outcomes were validated through measurements of lake sediment deposition. The findings indicate a potential high soil erosion risk. The validation of the model outcomes revealed that the TU Index model performed
significantly better than the RUSLE model with regard to sediment yield prediction. Accordingly, the AA. found that even though rill and interrill processes reach very alarming values (RUSLE), they are not the dominant sediment source within the Turano watershed
Key issues in local job accessibility measurement : different models mean different results
Accessibilité ; Commune ; Demande d'emploi ; Disponibilité de l'emploi ; Effet de frontière ; Emploi ; France ; Ile-de-France ; Marché local du travail ; Modèle ; Paris ; Trajet domicile-travail
Accessibility ; Employment ; Employment demand ; France ; Ile-de-France ; Journey to work ; Local labour market ; Model ; Municipality ; Paris
This examines key issues in local job accessibility and availability measurement in the Paris region municipalities. To do so, an original model where job availability is fully estimated according to a set of individual characteristics, job
competition is fully modelled on the local labour market and frontier effects are controlled for. It shows that the model-induced empirical differences are spatially differentiated , and that failing to fully estimate job availability may lead
Understanding river dune splitting through flume experiments and analysis of a dune evolution model
Auckland ; Cours d'eau ; Crue ; Dune hydraulique ; Expérimentation ; Géomorphodynamique ; Géométrie hydraulique ; Modèle ; North Island ; Nouvelle-Zélande
Auckland ; Channel geometry ; Current ripple ; Earth surface processes ; Experimentation ; Flood ; Model ; New Zealand ; North Island ; Stream
In this paper, the process of dune splitting is investigated by carrying out laboratory experiments and by means of a sensitivity analysis using a numerical dune evolution model. In the numerical model, the AA. introduced superimposed TRIAS ripples
(i.e. triangular asymmetric stoss side-ripples) on the stoss sides of underlying dunes as soon as these stoss sides exceed a certain critical length. Simulations with the model including dune splitting showed that predictions of equilibrium dune
characteristics were significantly improved compared to the model without dune splitting. As dune splitting is implemented in a parameterized way, the computational cost remains low which means that dune evolution can be calculated on the timescale of a flood wave
. Subsequently, the AA. used this model to study the mechanism of dune splitting. The sensitivity analysis of the dune evolution model showed that a minimum stoss side length was required to develop a strong flow separation zone.
Climatic change ; Ecosystem ; Environmental management ; European part of Russia ; Freshwater environment ; Impact ; Ladoga Lake ; Lake ; Mathematical model ; Model ; Onega Lake ; Water pollution
Analyse des modèles mathématiques de ces écosystèmes. Ces modèles fonctionnent comme des équations différentielles, ils utilisent les méthodes numériques actuelles et aussi des modèles dont la réalisation nécessite l'utilisation de la théorie des
sous-ensembles flous et de l’intelligence artificielle. En outre, les AA. présentent dans leur aperçu les modèles logiques, linguistiques et cognitifs qui donne une description qualitative des écosystèmes dulçaquatiques. Ils montrent entre autre que la
résolution du problème actuel d’impact des changements climatiques sur les écosystèmes lacustres est impossible sans modélisation. Les caractéristiques des modèles les plus utilisés pour les écosystèmes lacustres sont présentées dans un tableau.
Agent-based modeling in Coupled Human and Natural Systems (CHANS): lessons from a comparative analysis
Chine ; Environnement ; Interaction homme environnement ; Module standardisé ; Modèle ; Modèle agent ; Népal ; Parc national ; Paysage ; Réserve naturelle ; Tibet
China ; Environment ; Landscape ; Model ; National park ; Nature reserve ; Nepal ; Tibet
This article examines a Coupled human and natural systems -oriented protocol based on the overview, design concepts, and details (ODD) framework to help CHANS modelers and other researchers build, document, and compare CHANS-oriented ABMs Agent
-based models). Using this approach, it shows how complex demographic decisions, environmental processes, and human–environment interaction in CHANS can be represented and simulated in a relatively straightforward, standard way with ABMs by focusing
on a comparison of two world-renowned CHANS: the Wolong Nature Reserve in China and the Chitwan National Park in Nepal. The four key lessons we learn from this cross-site comparison in relation to CHANS models include how to represent agents and the landscape
, the need for standardized modules for CHANS ABMs, the impacts of scheduling on model outcomes, and precautions in interpreting “surprises” in CHANS model outcomes. It concludes with a CHANS protocol in the hope of advancing the science of CHANS.
Delayed delivery from the sediment factory : modeling the impact of catchment response time to tectonics on sediment flux and fluvio-deltaic stratigraphy
Accumulation fluviatile ; Bassin-versant ; Delta ; Fucino ; Italie ; Italie centrale ; Modèle ; Modèle numérique ; Précipitation ; Stratigraphie ; Tectonique ; Temps de réponse ; Transport sédimentaire ; Vitesse d'érosion
Central Italy ; Delta ; Erosion rate ; Fluvial deposit ; Italy ; Model ; Numerical model ; Precipitation ; Response time ; Sediment transport ; Stratigraphy ; Tectonics ; Watershed
In order to investigate the impact of catchment response time on sediment flux, the AA. integrated a spatially-lumped numerical model PaCMod, with new routines simulating the evolution of landscape morphology and erosion rates under tectonic
and climatic forcing. They subsequently applied the model to reconstruct the sediment flux from a tectonically perturbed catchment in central Italy. Finally, they coupled their model to DeltaSim, a process-response model simulating fluvio-deltaic stratigraphy
Hyperscale terrain modelling of braided rivers : fusing mobile terrestrial laser scanning and optical bathymetric mapping
Balayage laser terrestre ; Bathymétrie ; Chenal anastomosé ; Cours d'eau ; Géomorphodynamique ; Modèle ; Modèle numérique de terrain ; Nouvelle-Zélande ; Rees River ; South Island ; Transport sédimentaire
Bathymetry ; Braided channel ; Digital elevation model ; Earth surface processes ; Model ; New Zealand ; Sediment transport ; South Island ; Stream ; Terrestrial laser scanning
and mobility problems, respectively. In an attempt to confront these issues directly, this paper presents a novel survey methodology that combines mobile terrestrial laser scanning and non-metric aerial photography with data reduction and surface modelling
techniques to render DEMs from the resulting very high resolution datasets. The approach is used to generate and model a precise, dense topographic dataset for a 2.5 km reach of the braided Rees River, New Zealand. A detailed error analysis of the resulting
sub-metre resolution is described to quantify DEM quality across the entire surface model. This reveals unparalleled low vertical errors for such a large and complex surface model.
Very high resolution environmental predictors in species distribution models : Moving beyond topography?
Alpes ; Distribution spatiale ; Espèce végétale ; Modèle ; Modèle numérique de terrain ; Montagne ; Radiation ; Suisse ; Température ; Télédétection ; Vaud ; Végétation
Alps (The) ; Digital elevation model ; Model ; Mountain ; Plant species ; Radiation ; Remote sensing ; Spatial distribution ; Switzerland ; Temperature ; Vaud ; Vegetation
In this study, the AA. tested the influence, in species distribution models (SDMs), of predictors derived from a very high resolution (VHR) digital elevation model (DEM) by comparing the predictive power of models for 239 plant species
and their assemblages fitted at 6 different resolutions in the Swiss Alps. They also tested whether changes of the model quality for a species is related to its functional and ecological characteristics. The results suggest that improving resolution of topographic data
Remote sensing and hydrologic modeling are 2 key approaches to evaluate and predict hydrology and water resources. This paper presents an overview of research efforts to combine hydrologic/land models and remote sensing products (mainly including
Household ; Location ; Model ; Netherlands (The) ; Noord Brabant ; Public space ; Social geography ; Social interaction
This article examines social interaction location choice through a latent class modeling in Eindhoven region in the Netherlands. A latent class multinomial logit model is used to segment respondents in terms of their social activity location choices
Threshold of tolerance model : strategy for international travel
Australie ; Compagnie aérienne ; Gestion ; Modèle ; Organisation ; Seuil de tolérance ; Stratégie d'entreprise ; Transport ; Transport aérien ; Voyage d'affaires
Air transport ; Airline company ; Australia ; Business travel ; Firm strategy ; Management ; Model ; Organization ; Tolerance threshold ; Transport
successful international ventures or operating effectively in international markets. From the findings a strategic model was developed called the Threshold of Tolerance Model—which illustrates the potential point where both organisational goals are most