Search results for "Modelling"
showing 10 items of 1353 documents
Graphab: A software dedicated to the modelling of landscape networks
2016
International audience; Land cover changes resulting from urban sprawl, transport network intensification and agricultural changes contribute to fragment wildlife habitats and may lead to question viability of animal and plant populations. Landscape ecologists have shown that populations living in fragmented habitats are forced to adopt specific dynamics (patchy populations or metapopulations) making them highly dependent on fluxes between their habitat patches. Landscape connectivity may be defined as the functional response of a given species in terms of movement and individual fluxes to the potential links between habitat patches provided by the landscape structure.Many methods are used …
How could hydro-climatic conditions evolve in the long term in West Africa? The case study of the Bani River catchment
2011
International audience; This paper assesses the future variability of water resources in the long term over a large Sudano- Sahelian catchment in West Africa. Flow simulations were performed with a daily conceptual model. The climate models HadCM3 and MPI-M (based on SRES-A2) were used to provide future climate scenarios over the catchment. Outputs from these models were used to generate daily rainfall and temperature series for the 21st century according to: (i) application of the unbias and delta methods, and (ii) spatial and temporal downscaling. A temperature-based formula was used to calculate present and future potential evapotranspiration (PE). The daily rainfall and PE series were i…
Impact du changement climatique sur l’évolution de la ressource en eau en Bourgogne, France (1980-2100) - Analyse des paramètres hydroclimatiques sim…
2014
Impact of climate change on water resource evolution in Burgundy, France (1980-2011) – Analysis of hydro-climatic parameters simulated at high resolution by a regional climate model (WRF) The regional climatic model ARW / WRF is used to make a dynamic downscaling of climate (driven by ERA-Interim) at a high spatial resolution (3 km2) over Burgundy, at daily time scale over the period 1980-2011. Climatic simulations were analyzed and compared with meteorological data, in order to validate them with the aim of their use by hydro(geo)logic models. The hydro-climatic parameters necessary as climatic inputs of these models, in particular precipitation and evapotranspiration, reproduce correctly …
Linking traffic and noise models to explore spatio-temporal distribution of noise pollution: an example in Besançon (France)
2012
International audience; Road transportation is one of the major environmental noise sources in urban areas, which is characterized by an important temporal and spatial variation. Therefore, linking mobility and traffic model with noise model each representing spatial and temporal dimensions is a great interest. An integrated and original approach was developed to explore noise pollution in urban areas with a spatiotemporal and prospective point of view. An agent-based Land-Use and Transport Integrated (LUTI) model - MobiSim- was used to assess traffic modulation by simulating hourly flows and mobility. Individual choices of agents (representing the city's inhabitants) were transformed to fl…
Towards the improvement of food flavour analysis: Modelling chemical and sensory data and expert knowledge integration
2019
International audience
Modelling hydrolysis: Simultaneous versus sequential biodegradation of the hydrolysable fractions
2018
Hydrolysis is considered the limiting step during solid waste anaerobic digestion (including co-digestion of sludge and biosolids). Mechanisms of hydrolysis are mechanistically not well understood with detrimental impact on model predictive capability. The common approach to multiple substrates is to consider simultaneous degradation of the substrates. This may not have the capacity to separate the different kinetics. Sequential degradation of substrates is theoretically supported by microbial capacity and the composite nature of substrates (bioaccessibility concept). However, this has not been experimentally assessed. Sequential chemical fractionation has been successfully used to define i…
Modéliser la réponse des espèces marines antarctiques aux changements environnementaux. Méthodes, applications et limites.
2021
Among tools that are used to fill knowledge gaps on natural systems, ecological modelling has been widely applied during the last two decades. Ecological models are simple representations of a complex reality. They allow to highlight environmental drivers of species ecological niche and better understand species responses to environmental changes. However, applying models to Southern Ocean benthic organisms raises several methodological challenges. Species presence datasets are often aggregated in time and space nearby research stations or along main sailing routes. Data are often limited in number to correctly describe species occupied space and physiology. Finally, environmental datasets …
Macroecology of Southern Ocean echinoids : distribution, biogeography and modelisation
2011
What are the forcing factors and main patterns of species distribution? This question is the core of macroecological issues and is of particular interest in the present context of global warming. The main objectives of this thesis were to determine the current distribution patterns of Antarctic and sub-Antarctic echinoid species at the scale of the whole Southern Ocean and to highlight the forcing factors that control them. The ecological niche modelling of 19 echinoid species showed that distribution is mainly structured in two patterns: (1) a first one represented by species that are not limited to the south of the Polar Front and distributed from the Antarctic coasts to the sub-Antarctic…
Indicators for assessing the environmental impacts of land use changes across Europe
2008
International audience; Much progress has been made in understanding future trend development over the last years. Governments and international bodies are increasingly attempting to assess ex-ante the impact of their policy proposals. In the SENSOR project, environmental sustainability is assessed by answering a set of policy relevant questions likely to affect goods and services provided by land. The answer is complex and the assessment of future options is very sensitive to scale, how far ahead in time is being considered, and whether the assessment addresses local, regional or global concerns. The relationships between components of land use and the response of environmental indicators …
Consequences of gene flow between oilseed rape and wild radish
2013
International audience; Gene flow and introgression from crops to wild species can modify the adaptive potential and weediness of arable-land plant species. It gained recent importance with the release of genetically modified (GM) crops because of the risk of transfer of herbicide-resistance genes to related weeds. It is also a permanent possibility that could have occurred in the past with any conventional variety. In order to investigate this “normal” phenomenon and its impact, we developed three approaches in the framework of the study of gene flow between oilseed rape (Brassica napus) and wild radish (Raphanus raphanistrum). First, we compared the growth and reproduction of progeny of a…