References of "Cornet, Yves"
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See detailTransformée de Hough et détection de linéaments sur images satellitaires et modèles numériques de terrain
Poncelet, Nadia ULg; Cornet, Yves ULg

in Bulletin de la Société Géographique de Liège (2010), 54

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See detailAn Improved Methodology for Filling Missing Values in Spatiotemporal Climate Dataset: Application to Tanganyika Lake Dataset
Sorjamaa, Antti; Lendasse, Amaury; Cornet, Yves ULg et al

in Computational Geosciences (2010), 14(1), 55-64

In this paper, an improved methodology for the determination of missing values in a spatio-temporal database is presented. This methodology performs denoising projection in order to accurately fill the ... [more ▼]

In this paper, an improved methodology for the determination of missing values in a spatio-temporal database is presented. This methodology performs denoising projection in order to accurately fill the missing values in the database. The improved methodology is called EOF Pruning and it is based on an original linear projection method called Empirical Orthogo- nal Functions (EOF). The experiments demonstrate the performance of the improved methodology and present a comparison with the original EOF and with a widely-used Optimal Interpolation method called Objective Analysis. [less ▲]

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See detailUse of multi-angle high-resolution imagery and 3D information for urban land-cover classification: a case study on Istanbul
Binard, Marc ULg; Tack, Frederik; Van de Voorde, Tim et al

in Joint SIG Workshop Urban - 3D - Radar - Thermal Remote Sensing and Developing Countries - Ghent, 22-24 September 2010 Book of Proceedings EUROPEAN ASSOCIATION OF REMOTE SENSING LABORATORIES (2010)

The BELSPO-MAMUD project focuses on the use of remote sensing data for measuring and modelling urban dynamics. Remote sensing is a wonderful tool to produce long time-series of sealed surface maps, which ... [more ▼]

The BELSPO-MAMUD project focuses on the use of remote sensing data for measuring and modelling urban dynamics. Remote sensing is a wonderful tool to produce long time-series of sealed surface maps, which are useful for this purpose. In the urban context of Istanbul, a very dynamic city, recent high resolution satellite images and medium resolution images from the past have been exploited to calibrate and validate a regression-based sub-pixel classification method allowing this production. Image classification in an urban context is a tricky task for several reasons: prominent occurrence of shadowed and occluded areas and urban canyons, spectral confusions between urban and non-urban materials at ground and roof levels, moderately hilly relief ... To cope with these difficulties the combined use of three types of data may be helpful: diachronic (vii), multi-angle and 3D data. A master multispectral and panchromatic QuickBird image and a panchromatic Ikonos stereopair, all acquired in March 2002, were used in combination with a multispectral and panchromatic Ikonos image of May 2005. A DSM was generated from the Ikonos stereopair and building vector file. It was used for orthorectification, building height estimation and classification. The area covered by the high resolution products was divided in 3 parts and each was classified independently. This application demonstrates that a recent high resolution land-cover classification produced using multi-date, multi-angle and DSM can be used to produce sealed surface maps from longer time-series of medium resolution images over large urban areas, thus enabling the analysis of urban dynamics. [less ▲]

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See detailUsing information on urban morphology derived from a time-series of medium resolution remote sensing data for the calibration of the moland urban growth model
van der Kwast; Van de Voorde, Tim; Binard, Marc ULg et al

in Joint SIG Workshop Urban - 3D - Radar - Thermal Remote Sensing and Developing Countries, Book of Proceedings EUROPEAN ASSOCIATION OF REMOTE SENSING LABORATORIES (2010)

Land-use change models are more and more used by planners and policy makers as tools to assess the impacts of their decisions on the spatial systems that they are to manage. To be usefully applicable the ... [more ▼]

Land-use change models are more and more used by planners and policy makers as tools to assess the impacts of their decisions on the spatial systems that they are to manage. To be usefully applicable the models need extensive calibration. Typically the required time series of land-use maps based on identical and consistent mapping methodologies, legends and scales are missing. As a result, the land-use changes measured in the time intervals studied are often the result of mismatches in the mapping procedures rather than real changes in the land-use patterns of interest. As an alternative, land-use products inferred from archived medium resolution remote sensing images have a large potential for usage in the historic calibration of land-use change models. However, inferring land-use classes from remote sensing data is not straightforward. Therefore, a calibration framework for land-use change modelling is being developed which is based on the comparison of spatial metrics derived from both remote sensing images and simulation results. Parameters used in the simulation model are tuned in such a way that the simulated patterns of urban growth, as described by the metrics, match the patterns observed in the remote sensing imagery. This study evaluates the applicability of spatial metrics calculated from urban masks derived from remote sensing images and simulated land-use maps for the historic calibration of the EU-MOLAND model of Dublin. Results show that the historic calibration can be improved by using remote sensing derived spatial metrics. [less ▲]

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See detailInferring urban morphology for the greater Dublin area from continuous sealed surface data: a metric based approach
Van de Voorde, Tim; Binard, Marc ULg; Cornet, Yves ULg et al

in Joint SIG Workshop Urban - 3D - Radar - Thermal Remote Sensing and Developing Countries Ghent, 22-24 September 2010 Book of Proceedings EUROPEAN ASSOCIATION OF REMOTE SENSING LABORATORIES (2010)

Urban land-use change models are valuable tools for assessing the spatial impact of alternative planning strategies via scenario analysis. A trustworthy output can only be obtained if the models are ... [more ▼]

Urban land-use change models are valuable tools for assessing the spatial impact of alternative planning strategies via scenario analysis. A trustworthy output can only be obtained if the models are correctly calibrated and validated, which requires historic land-use data. Land-use information is often inconsistent or unavailable at the desirable time interval. Earth observation satellites supply regular information on urban development and can provide additional data to improve calibration. To study urban growth patterns with a time-span that exceeds the availability of high resolution imagery, a mapping approach is required that succeeds in capturing structural information from medium resolution images. A rather novel approach in this research area is to describe urban structure by means of spatial metrics, which are usually applied on categorical data such as land-cover maps. The main objective of our research was to quantify the spatial structure of the Greater Dublin Area by applying metrics on continuous sealed surface data. Three types of urban metrics were derived at the level of spatial units (blocks): average building density, distribution characteristics of sub-pixel sealed surface fractions and spatial variability. Using these spatial metrics as quantitative variables describing urban structure, a supervised classification based on a multi-layer perceptron classifier was used to infer basic land-use categories. With this approach, we were able to distinguish broad land-use types such as residential areas and employment zones (e.g. industrial, commercial). This distinction is relevant for urban modelling as these classes represent important driving factors. Results of applying the proposed methodology on a timeseries of Landsat images are currently being used for improving the calibration of the MOLAND land-use model for Dublin. [less ▲]

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See detailSpatio-temporal dynamics of phytoplankton and primary production in Lake Tanganyika using a MODIS based bio-optical time series
Bergamino, Nadia; Horion, Stéphanie; Stenuite, Stéphane et al

in Remote Sensing of Environment (2010)

Lake Tanganyika, the second largest freshwater ecosystem in Africa, is characterised by a significant heterogeneity in phytoplankton concentration linked to its particular hydrodynamics. To gather a ... [more ▼]

Lake Tanganyika, the second largest freshwater ecosystem in Africa, is characterised by a significant heterogeneity in phytoplankton concentration linked to its particular hydrodynamics. To gather a proper understanding of primary production, it is necessary to consider spatial and temporal dynamics throughout the lake. In the present work, daily MODIS-AQUA satellite measurements were used to estimate chlorophyll-a concentrations and the diffuse attenuation coefficient (K490) for surface waters. The spatial regionalisation of Lake Tanganyika, based on Empirical Orthogonal Functions of the chlorophyll-a dataset (July 2002–November 2005), allowed for the separation of the lake in 11 spatially coherent and co-varying regions, with 2 delocalised coastal regions. Temporal patterns of chlorophyll-a showed significant differences between regions. Estimation of the daily primary production in each region indicates that the dry season is more productive than the wet season in all regions with few exceptions. Whole-lake daily primary productivity calculated on an annual basis (2003) was 646±142 mgC m−2 day−1. Comparing our estimation to previous studies, photosynthetic production in Lake Tanganyika appears to be presently lower (about 15 %), which is consistent with other studies which used phytoplankton biovolume and changes of δ13C in the lake sediments. The decrease in lake productivity in recent decades may be associated to changes in climate conditions. [less ▲]

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See detailOptimized extraction of daily bio-optical time series derived from MODIS/Aqua imagery for Lake Tanganyika, Africa
Horion, Stéphanie; Bergamino, Nadia; Stenuite, Stéphane et al

in Remote Sensing of Environment (2010)

Lake Tanganyika is one of the world's great freshwater ecosystems. In recent decades its hydrodynamic characteristics have undergone important changes that have had consequences on the lake's primary ... [more ▼]

Lake Tanganyika is one of the world's great freshwater ecosystems. In recent decades its hydrodynamic characteristics have undergone important changes that have had consequences on the lake's primary productivity. The establishment of a long-term Ocean Color dataset for Lake Tanganyika is a fundamental tool for understanding and monitoring these changes. We developed an approach to create a regionally calibrated dataset of chlorophyll-a concentrations (CHL) and attenuation coefficients at 490 nm (K490) for the period from July 2002 to December 2006 using daily calibrated radiances retrieved from the MODIS-Aqua sensor. Standard MODIS Aqua Ocean Color products were found to not provide a suitable calibration for high altitude lakes such as the Lake Tanganyika. An optimization of the extraction process and the validation of the dataset were performed with independent sets of in situ measurements. Our results show that for the geographical, atmospheric and optical conditions of Lake Tanganyika: (i) a coastal aerosol model set with high relative humidity (90%) provides a suitable atmospheric correction; (ii) a significant correlation between in situ data and CHL estimates using the MODIS specific OC3 algorithm is possible; and (iii) K490 estimates provide a good level of significance. The resulting validated time series of bio-optical properties provides a fundamental information base for the study of phytoplankton and primary production dynamics and interannual trends. A comparison between surface chlorophyll-a concentrations estimated from field monitoring and from the MODIS based dataset shows that remote sensing allows improved detection of surface blooms in Lake Tanganyika. [less ▲]

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See detailModelling climate control on cropland and grassland development using phenologically tuned variables
Horion, Stéphanie; Tychon, Bernard ULg; Cornet, Yves ULg

in Geophysical Research Abstracts (2010), 12

Many studies already investigated the impact of climate change and climate variability on vegetation at global and continental scales. Using time series of remote sensing and climate data, Nemani et al ... [more ▼]

Many studies already investigated the impact of climate change and climate variability on vegetation at global and continental scales. Using time series of remote sensing and climate data, Nemani et al. (2003) analyzed trends in Net Primary Production in relation with changes in climate and showed that, between 1982 and 1999, primary productivity increased by 6% globally in response to climate change. This study also stressed the need to take into account the spatial variability of climatic constraints to plant growth when analyzing the climate change impact on vegetation. Others authors described different phenomenon linked with climate change such as increases of seasonal NDVI amplitude and growing season duration in the Northern high latitude or changes in circumpolar photosynthetic activities. Understanding the interactions between climate and vegetation is also a key issue in our PhD research. Our objective is to identify the meteorological factors which limit the development of croplands and grasslands in relation with their geographical localization. For that purpose, we acquired 10-daily time series of the Normalized Difference Vegetation Index, NDVI, derived from SPOT-VEGETATION and 7 meteorological parameters (Tmean, Tmin, Tmax, Rain, Rad, ETP, Rain-ETP) derived from ERA40 re-analyses and the operational ECMWF (European Centre for Medium-Range Weather Forecast) atmospheric model. Cross-correlations between NDVI and each one of the meteorological parameters were analysed for a set of 25 regions over Europe and Africa: 15 agricultural regions and 10 regions covered by grassland or savannas. Unlike others studies, we did not consider the vegetation globally but we focussed on two types of vegetation: croplands and grasslands. This is quite important considering the role of phenology on the vegetation cycle and its relation with climate. Moreover the analysis was not realised using yearly estimates but using 10-daily products. In order to avoid stationarity related issue, a specific methodology was developed taking into account the phenological cycle of the vegetation under consideration. Preliminary results showed that the relation between a meteorological limiting factor, e.g. precipitation, and NDVI can not be considered as linear during the year or even during the growing season. Interactions must to be studied at a smaller time scale than the growing season in order to identify properly the limiting factors to plant growth taking into account its phenology. Moreover the main limiting factors are variable from a region to another. In our analysis we also considered the possibility of a delayed response of the vegetation or a cumulated effect of meteorological events (up to 3 months). Our methodology will be presented during the conference and results will be discussed and illustrated by some test cases. [less ▲]

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See detailCombining spatial data in landslide reactivation susceptibility mapping: A likelihood ratio-based approach in W Belgium
Dewitte, Olivier ULg; Chung, Chang-Jo; Cornet, Yves ULg et al

in Geomorphology (2010)

A key issue in landslide susceptibility mapping concerns the relevance of the spatial data combination used in the prediction. Various combinations of high-resolution predictor variables and possibilities ... [more ▼]

A key issue in landslide susceptibility mapping concerns the relevance of the spatial data combination used in the prediction. Various combinations of high-resolution predictor variables and possibilities of selecting them from a larger dataset are analysed. The scarp reactivation of several landslides in a hilly region of W Belgium is investigated at the pixel scale. The usceptibility modelling uses the reactivated scarp segments as the dependent variable and 13 factors at a 2 m-resolution related to topography, hydrology, land use and lithology as potential independent variables. The modelling uses a likelihood ratio approach based on the comparison, for each independent variable, between two empirical distribution functions (EDFs), respectively for the reactivated and non-reactivated areas. It uses these EDFs as favourability values to build membership values and combine them with a fuzzy Gamma operator. Five different data combinations are tested and compared by analysing the prediction-rate curves obtained by cross-validation. The geomorphological value of the resulting susceptibility maps is also discussed. This research shows relevant results for predicting the susceptibility to scarp reactivation. We highlight the need for testing several data combinations and underline that combining uantitative criteria with expert opinion is an asset for reliable predictions. [less ▲]

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See detailLimnological variability and pelagic fish abundance (Stolothrissa tanganicae and Lates stappersii) in Lake Tanganyika
Plisnier, P. D.; Mgana, H.; Kimirei, I. et al

in Hydrobiologia (2009), 625(1), 117-134

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See detailAnalysis of lateral mobility of channels at different spatial and time scales (Ardenne massif, Belgium)
Houbrechts, Geoffrey ULg; Van Campenhout, Jean ULg; Hallot, Eric ULg et al

Poster (2009)

Lateral mobility of Ardenne rivers has been studied at different scales using three complementary methods. We firstly compared the layout of channels on topographic maps (since the 18th century) and ... [more ▼]

Lateral mobility of Ardenne rivers has been studied at different scales using three complementary methods. We firstly compared the layout of channels on topographic maps (since the 18th century) and aerial pictures. Given that these documents have different scales and projection systems, they were transformed into a common referencing system. This method allowed us to study the lateral shifting of channels, however, as the mobility of Ardenne rivers is relatively low, the errors of geometric rectifications are often more important than lateral displacements. Therefore, to visualize these deformations, georeferenced documents were overlaid with a regular grid of points. We represented the imprecision vector based on x and y residual components for each point. These vectors show the direction of the deformation and its amplitude. Large quantities of iron slag are present in the sediments of Ardenne rivers. These waste products come from hundreds of ironworks built close to rivers since the 14th century. Analyses of slag concentrations in alluvial deposits allowed us to delimitate the sectors of floodplains eroded by rivers during the last centuries. In these sectors, slag elements are present at the contact with the gravel sheet. Finally, we analysed the topography of floodplains from a DEM-LIDAR. This digital elevation model has been established by the Walloon Region for the cartography of flood risk in floodplains. It presents a Z mean error of only 15 cm and a X-Y resolution of 1 m. In order to reveal paleochannels and topographic alluvial units, we subtracted a surface, corresponding to the longitudinal water surface slope, extracted from the DEM. By using this method, we are able to obtain the relative height of any point of the floodplain with regard to the water surface, projected perpendicularly to the layout, on this point. This procedure reveals paleochannels even if they are almost infilled and allows us to delimitate, for several kilometres, alluvial units, which have been formed at different periods. [less ▲]

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See detailQuantifying intra-urban morphology of the Greater Dublin area with spatial metrics derived from medium resolution remote sensing data
Van de Voorde, Tim; van der Kwast, Johannes; Engelen, Guy et al

in IEEE Proceedings of the 7th International Urban Remote Sensing Conference : Shanghai, May 20-22, 2009 (2009)

Spatial metrics derived from satellite imagery are useful measures to quantify structural characteristics of expanding cities, and can provide indications of functional land use types. Images of medium ... [more ▼]

Spatial metrics derived from satellite imagery are useful measures to quantify structural characteristics of expanding cities, and can provide indications of functional land use types. Images of medium resolution are cheap, widely available and are often part of extensive historic archives. Their lower resolution, on the other hand, inhibits studying urban morphology and change processes at a more detailed, intra-urban level. In this study, we develop spatial metrics for use on continuous sealed surface data produced by a sub-pixel classification of Landsat ETM+ imagery. The metrics characterise the shape of the cumulative frequency distribution of the estimated sub-pixel fractions within a building block by fitting an exponential and a sigmoid function with a least-squares approach. A classification tree is then used to relate the metric variables to urban land-use classes selected from the European MOLAND topology. This approach shows promising results, but still needs improvement which may be achieved by including spatially explicit metrics in the analysis. [less ▲]

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See detailCharacterising urban morphology with spectral unmixing and spatial metrics: a case study on Dublin
Canters, Frank; Van de Voorde, Tim; Binard, Marc ULg et al

in Proceedings of the 24th International Cartographic Conference (ICC 2009), (2009)

In today’s urbanising world, effective urban management and planning strategies are needed to temper the impact of urban change processes on the natural and human environment. To develop and monitor such ... [more ▼]

In today’s urbanising world, effective urban management and planning strategies are needed to temper the impact of urban change processes on the natural and human environment. To develop and monitor such strategies, and to assess their spatial impact, analysing changes in urban structure is essential. Data from earth observation satellites provide regular information on urban development and, as such, may contribute to the mapping and monitoring of cities and the modelling of urban dynamics. Especially images of medium resolution (Landsat, SPOT, …), which are cheap, widely available and often part of extensive historic archives, offer a wealth of information that may be useful for urban monitoring purposes. The lower resolution of this type of imagery, however, hampers the study of urban morphology and change processes at a more detailed, intra-urban level. Spectral unmixing approaches, which allow characterising land-cover distribution at sub-pixel level, may partly compensate for this lack of spatial detail, and may render medium-resolution imagery more useful for urban studies. The main research question addressed in this paper is how medium-resolution imagery could be used to describe urban morphology, by combining spectral unmixing approaches with spatial metrics. Spatial metrics derived from satellite imagery may be useful to quantify structural characteristics of expanding cities, and may provide indications of functional land use. In this study, we develop a set of urban metrics for use on continuous sealed surface data produced by sub-pixel classification of Landsat ETM+ imagery. Two sub-pixel classification approaches are examined for that purpose. In a first approach, we use a linear spectral mixture model with a vegetation and a non-vegetation endmember to deconvolve each pixel’s spectrum into fractional abundances of the two end member spectra, which are determined by visualising mixture space with principal component analysis. In a second approach, we use a linear regression model to estimate the proportion of vegetation cover within each Landsat pixel. In both approaches, an urban mask is used to indicate pixels belonging to urban land cover. Only pixels within the urban mask are subjected to sub-pixel classification. We hereby assume that the urban area does not contain bare soil and that the area of a pixel not covered by vegetation fully consists of sealed surface cover. The resulting sealed surface proportion map is then used to characterise urban morphology and land use by means of the shape of the cumulative frequency distribution of the estimated sealed surface fractions within a building block. A transformed logistic function is fitted to this distribution with a least-squares approach to obtain function parameters that are used as variables in a supervised classification approach, together with spatially explicit metrics (spatial variance and Moran’s I). Our study demonstrates that images from medium resolution sensors can be used to characterise intra-urban morphology, and that the structure of a building block as described by the proposed metrics gives an indication of its membership to certain morphological/functional urban classes. In future research we will incorporate socio-economic data in the metric analysis to further improve the distinction of urban land-use categories. The spatial metrics approach developed in this study will be used in experiments to improve the calibration of the MOLAND urban growth model, which is currently calibrated with historical land-use maps available for approximately 10-year intervals. [less ▲]

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See detailPrédiction des zones propices au ravinement par un modèle de régression logistique intégrant des données de télédétection. Cas du sous-bassin versant de l’oued Alayem - Beni Slimane, Algérie
Daoudi, Mohamed; Ozer, André ULg; Gérard, Paul ULg et al

in Randriamanga, Simone; Rakotoniaina, Solofoarisoa; Auda, Yves (Eds.) et al Les XIèmes Journées Scientifiques du Réseau Télédétection de l'AUF (2008, November 03)

Le sous-bassin versant de l'oued Alayem - Beni Slimane, d’une superficie de 118 km², constitue une zone d'étude d'intérêt particulier en raison des caractéristiques physicoclimatiques représentatives de ... [more ▼]

Le sous-bassin versant de l'oued Alayem - Beni Slimane, d’une superficie de 118 km², constitue une zone d'étude d'intérêt particulier en raison des caractéristiques physicoclimatiques représentatives de la zone tellienne méditerranéenne. Le processus de ravinement y est très répandu et constitue un problème majeur. Les facteurs physiques et anthropiques contribuent à une accélération du phénomène. Le présent travail propose une méthode multivariée, basée sur des données multisources, afin de déterminer les variables indépendantes significatives qui favorisent l’existence de l’érosion ravinante et calculer la probabilité des zones de susceptibilité au processus de ravinement. Des variables explicatives toutes liés aux caractéristiques physico-climatiques sont retenues pour le modèle : il s’agit de la lithologie, la pente, l’orientation des versants, l’altitude (MNT), la morphopédologie, la couverture du sol (PVI) et l’agressivité des précipitations (Indice R). Elles permettent de généraliser le modèle prédictif pour des régions semblables du nord de l’Algérie ou du Maghreb. [less ▲]

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See detailTracking landslide displacements by multi-temporal DTMs: A combined aerial stereophotogrammetric and LIDAR approach in western Belgium
Dewitte, Olivier ULg; Jasselette, J. C.; Cornet, Yves ULg et al

in Engineering Geology (2008), 99(1-2), 11-22

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See detailAn automated method to extract fluvial terraces from digital elevation models: The Vesdre valley, a case study in eastern Belgium
Demoulin, Alain ULg; Bovy, Benoît ULg; Rixhon, Gilles ULg et al

in Geomorphology (2007), 91(1-2), 51-64

Fluvial terraces are a powerful tool for unraveling the combined tectonic and climatic conditions that controlled, directly or indirectly, the Quaternary incision of rivers. Terrace long profiles are ... [more ▼]

Fluvial terraces are a powerful tool for unraveling the combined tectonic and climatic conditions that controlled, directly or indirectly, the Quaternary incision of rivers. Terrace long profiles are usually retrieved from sparse traces of ancient floodplains preserved in the present topography. However, when these traces classically collected from topographic maps, aerial photographs, and field analyses are too few, the inferred profiles may be questionable. Yet the now available high quality and high resolution digital elevation models (DEMs) offer an opportunity to increase greatly the quantity of information usable to reconstruct terrace profiles. Therefore, the purpose of this study was to develop a new DEM-based method of terrace recognition in order to create a larger database and better constrain the profile reconstruction. Moreover, particular procedures of image and numerical processing were defined to fully automate the analysis. Basically, our method relies on the production of bivariate scatter plots depicting the relation between slope and relative altitude (i.e., the altitude above the current alluvial plain) for all pixels of successive sections of the valley. For each scatter plot, the curve of the lowest slope values observed at every relative altitude is smoothed and its minima are assumed to locate the altitudes of the "terrace" elements preserved in the section. We successfully tested this method in the Vesdre valley, incised in the NE Ardenne massif (E Belgium), notably identifying fault deformation of the profiles. The main advantages of our approach are its objectivity, exhaustiveness, and rapidity, allowing fast and coherent analysis of many rivers over extended regions. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailSpatial aggregation of low resolution satellite data for the monitoring of vegetation response to climatic stresses : analysis of the spatial heterogeneity of aggregated entities.
Horion, Stéphanie; Eerens, H.; Tychon, Bernard ULg et al

in Proceedings Envisat Symposium (2007, July)

Our PhD research consists in analysing and modelling the vegetation response or sensitivity to climatic stresses with low satellite imagery. In that framework, the selection of optimal calibration sites ... [more ▼]

Our PhD research consists in analysing and modelling the vegetation response or sensitivity to climatic stresses with low satellite imagery. In that framework, the selection of optimal calibration sites is very important. These sites should be characterised by a stable and homogenous land cover over large area. Here we analyse the spatial heterogeneity of the aggregation entities (EU-NUTS 2) used by the MARSFOOD programme for the extraction of regional NDVI-means. [less ▲]

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