References of "Tychon, Bernard"
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See detailGestion interdisciplinaire du problème d'ensablement des cuvettes en milieu sahélien nigérien
Tychon, Bernard ULg; Ambouta, K, J-M

in Geo-Eco-Trop (2009), 33

Niger faces the brunt of desertification in the Sahelian belt. Many national and international programs attempt to help the country fight against this serious environmental degradation. This article ... [more ▼]

Niger faces the brunt of desertification in the Sahelian belt. Many national and international programs attempt to help the country fight against this serious environmental degradation. This article relies on an inter-university targeted program (ITP) funded by the Coopération Universitaire au Développement (CUD) called "Invasion of circular lowlands (cuvettes) of south-eastern Niger by aeolian deposits: processes, impacts and means of struggle" to demonstrate the interest of an inter / multidisciplinary approach in the research of a better solution to an environmental problem as comprehensive as that of desertification. The study is focused on a specific form of desertification, which is that of silting “cuvettes”, areas of lowlands in the south-eastern Niger. Two examples illustrate the practical contribution of this type of approach. The article also shows the link between all the teams who have contributed to the results of the ITP and the development of this special issue. [less ▲]

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See detailPerspectives - Quel avenir pour les cuvettes oasiennes dans le Niger oriental ?
Tychon, Bernard ULg; Ambouta, Karimou Jean-Marie; Ozer, André ULg et al

in Geo-Eco-Trop (2009), 33

The oasian interdunal depressions of eastern Niger are areas of life providing refuge to agro-pastoral activities in a generally hostile environment. The inter-university Targeted Program (ITP) funded by ... [more ▼]

The oasian interdunal depressions of eastern Niger are areas of life providing refuge to agro-pastoral activities in a generally hostile environment. The inter-university Targeted Program (ITP) funded by the Coopération Universitaire au Développement (CUD) called "Invasion of circular lowlands (cuvettes) of south-eastern Niger by aeolian deposits: processes, impacts and means of struggle" has studied the problem of silting of these refuge areas and proposed technical means, including physical and biological fixation of dunes that threaten the villages and interdunal depressions. Given the increasing human pressure and the present climate context that seems to move towards dryer conditions, environmental degradation of the study area should be investigated more broadly. Set up of strategies to allow people to adapt their conditions of life to an environment increasingly rough should also be considered. This paper presents some possible options for adaptation and examines the question of the very future of these interdunal depressions. [less ▲]

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See detailStatistical Analysis of the night weather conditions favouring the epidemic of the brown rust in the Grand-Duchy of Luxemburg.
El Jarroudi, Moussa ULg; Tychon, Bernard ULg; Maraite, Henri et al

in Italian Journal of Agronomy/ Rivista di Agronomia (2008), 3

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See detailService operations report SENEGAL 2007
Delrue, Josefien; Barbieri, Massimo; Tychon, Bernard ULg et al

Report (2008)

GMFS (Global Monitoring for Food Security) is a GMES Service Element (GSE) project, part of the ESA contribution to the EU / ESA GMES (Global Monitoring for Environment and Security) Programme. GMFS aims ... [more ▼]

GMFS (Global Monitoring for Food Security) is a GMES Service Element (GSE) project, part of the ESA contribution to the EU / ESA GMES (Global Monitoring for Environment and Security) Programme. GMFS aims to establish an earth observation based operational service for crop monitoring to support food security decision makers and EU policy objectives. The aim of this document, as expressed in the statement of work is to: - Evaluate the operations planned versus the services agreed - Review the external infrastructure - Review issues and experiences with relation to adopted standards The aim of the document is to give a complete report of all activities executed by the service partners to deliver agricultural monitoring services to the Centre de Suivi Ecologique (CSE) in Senegal for the 2007 growing season. [less ▲]

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See detailMonitoring soil organic carbon in croplands using imaging spectroscopy (moca project)
Stevens, Antoine; van Wesemael, Bas; Tychon, Bernard ULg et al

Conference (2008, February 12)

The detection of changes in soil organic carbon (SOC) concentration is essential in both the assessment of SOC sequestration and soil quality. Within the EU soil thematic strategy the depletion of organic ... [more ▼]

The detection of changes in soil organic carbon (SOC) concentration is essential in both the assessment of SOC sequestration and soil quality. Within the EU soil thematic strategy the depletion of organic matter is mentioned as one of the major threats to the soil resource. As one of the first countries Luxemburg has taken the initiative to monitor the SOC concentration of individual fields to allow for eventual CO2 credits and as an indicator for good agro-ecological conditions (GAEC). The aim of this project is to develop an efficient and operational methodology to detect SOC changes in croplands using Imaging Spectroscopy and to map the SOC contents of croplands with high resolution and minimal calibration. [less ▲]

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See detailGlobal agricultural monitoring systems by integration of earth observation and modelling techniques (globam project).
Defourny, Pierre; Bériaux, Emilie; Tychon, Bernard ULg et al

Conference (2008, February 12)

Nowadays, food security and crop production variability become a major concern. Moreover, in spite of major technological and methodological EO improvements observed since the late 1990’s, very little ... [more ▼]

Nowadays, food security and crop production variability become a major concern. Moreover, in spite of major technological and methodological EO improvements observed since the late 1990’s, very little change has been observed in the operational systems. A major gap exists between the remote sensing operationally used and the current scientific state of the art in EO crop monitoring. There is a lack of relevant field data over large areas, and these data are very much needed to gain a better understanding of potential improvements of the operational systems. [less ▲]

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See detailMonitoring of the dynamics of the natural resources by the geomatic in Morocco
Mahyou, Hamid ULg; Tychon, Bernard ULg

Scientific conference (2008, January 29)

Drylands cover about 40 % of Earth’s land surface and are inhabited by more than 2 billion people who depend mainly on the exploitation of these dryland ecosystem natural resources. However, it is largely ... [more ▼]

Drylands cover about 40 % of Earth’s land surface and are inhabited by more than 2 billion people who depend mainly on the exploitation of these dryland ecosystem natural resources. However, it is largely recognized that these areas are threatened by the desertification. Desertification is associated with biodiversity loss and contrib-utes to global climate change. In spite of the importance of this phenomenon, it is surprising that there is no consensus on an appropriate method to assess this degradation process. One part of the literature announces catastrophic statistics on the rate of desert extension and surface affected. Others, doubt about the methodology used by these first studies and do not find any obviousness of such an extent of desertification. The overall goal of our study is to develop remote sensing based indicators and models for the assessment of desertification in drylands. For this purpose, the monitoring of vegetation and soil is based on information resulting from the remote sensing and the biophysics data. Hyperspectral (field and remote sensing) and biophysics parameters will be established for the study area through large field campaigns combined with HR-remote sensing data. The Land Cover will be mapped using the Landsat TM images in conjunction with measurements of vegetation parameters such as biomass and vegetation cover. Hyperspectral reflectances of the vegetation and soil inside the study zone will be measured by a Spectroradiometer. Each site will be located by Global Positioning System (GPS). Several RS vegetations indices appropriate for rangeland will be studied and others will be developed. Regression analyses, between the different vegetation indices retained by remote sensing and the biophysics data will be carried out so as to establish a spatio-temporal model linking these indices to the vegetation parameters. This research has started in November 2007 [less ▲]

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See detailUtilisation des prises de vue aérienne à basse altitude pour le suivi des activités hydro-agricoles – Cas du Bassin du Kou
Wellens, Joost; Diallo, M.; Dakouré, D. et al

Scientific conference (2008, January 29)

Le bassin du Kou, situé dans le sud-ouest du Burkina Faso, est depuis quelques décennies le théâtre de différentes formes de conflits liés à toute une série de problèmes que l’on rencontre généralement ... [more ▼]

Le bassin du Kou, situé dans le sud-ouest du Burkina Faso, est depuis quelques décennies le théâtre de différentes formes de conflits liés à toute une série de problèmes que l’on rencontre généralement dans des zones irriguées. Dans le bassin du Kou, les aménagements hydro-agricoles recensés couvrent une superficie otale de près de 3.200 ha ; il s’agit pour l’essentiel de périmètres privés formant la ceinture maraîchère et horticole de Bobo-Dioulasso et d’un grand périmètre de 1.200 ha réalisé par l’Etat à Bama et spécialisé dans la production du riz. Le développement d’une filière fruits et légumes sous l’impulsion de l’initiative privée est un trait caractéristique de la production irriguée dans la région. Outre l’abondance en eau liée à la présence de sources importantes, d’une nappe phréatique facilement exploitable, d’un cours d’eau pérenne et un hivernage à caractère sub-humide, la plupart des utilisateurs d’eau se retrouvent régulièrement en pénurie d’eau suite à l’extension non contrôlée de l’agriculture irriguée. Ceci a conduit les gestionnaires du bassin à rechercher des outils de contrôle et de suivi. A partir de plus de 300 prises de vue aérienne ‘amateurs’ à basse altitude, ayant une résolution de 0,8 m., une image d’occupation détaillée des sols a pu être élaborée. Des logiciels de mosaïquage, de traitement d’images et de SIG ont permis la construction d’une seule image géoréférencée. Les parcelles agricoles irriguées ont ainsi pu être délimitées. Leurs occupations ont été comparées et complétées avec les résultats d’un recensement hydro-agricole exhaustif organisé au même moment. Cette technique permet un suivi spatial des activités agricoles à moindre coût par rapport à l’acquisition des images satellites à haute résolution. L’approche est également moins sensible aux influences atmosphériques non-prévisibles dans la programmation des images satellites. Elle répond avec une précision largement suffisante aux objectifs de suivi et contrôle des parcelles irriguées demandés par les gestionnaires du bassin. [less ▲]

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See detailEmpirical regression models using NDVI, rainfall and temperature data for the early prediction of wheat grain yields in Morocco
BALAGHI, Riad; Tychon, Bernard ULg; EERENS, Herman et al

in International Journal of Applied Earth Observation and Geoinformation (2008), 10

In Morocco, no operational system actually exists for the early prediction of the grain yields of wheat (Triticum aestivum L.). This study proposes empirical ordinary least squares regression models to ... [more ▼]

In Morocco, no operational system actually exists for the early prediction of the grain yields of wheat (Triticum aestivum L.). This study proposes empirical ordinary least squares regression models to forecast the yields at provincial and national levels. The predictions were based on dekadal (10-daily) NDVI/AVHRR, dekadal rainfall sums and average monthly air temperatures. The Global Land Cover raster map (GLC2000) was used to select only the NDVI pixels that are related to agricultural land. Provincial wheat yields were assessed with errors varying from 80 to 762 kg ha 1, depending on the province. At national level, wheat yield was predicted at the third dekad of April with 73 kg ha 1 error, using NDVI and rainfall. However, earlier forecasts are possible, starting from the second dekad of March with 84 kg ha 1 error, at least 1 month before harvest. At the provincial and national levels, most of the yield variation was accounted for by NDVI. The proposed models can be used in an operational context to early forecast wheat yields in Morocco. [less ▲]

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See detailGreen leaf area decline of the last three leaves of wheat. Determination of the relationships with remote sensing green land cover.
Mackels, Christophe; Tychon, Bernard ULg

in Italian Journal of Agronomy [=IJA] = Rivista di Agronomia (2008), 3(3), 671-672

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See detailLaboratory, field and airborne spectroscopy for monitoring organic carbon content in agricultural soils.
Stevens, A.; Van Wesemael, B.; Bartholomeus, H. et al

in Geoderma (2008), 144

The temporal evolution in Soil Organic Carbon (SOC) content is often used in estimations of greenhouse gas fluxes and is an important indicator of soil quality. Regional estimates of SOC changes can only ... [more ▼]

The temporal evolution in Soil Organic Carbon (SOC) content is often used in estimations of greenhouse gas fluxes and is an important indicator of soil quality. Regional estimates of SOC changes can only be obtained by analyzing very large number of samples over large areas due to the strong spatial variability in SOC contents. Visible and Near Infrared Spectroscopy (VNIRS) provides an alternative to chemical analyses. The benefits of this technique include a reduction of the sampling processing time, an increase of the number of samples that can be analyzed within time and budget constraints and hence an improvement of the detection of small changes in SOC stocks for a given area. Carbon contents are predicted from spectra through Partial Least Square Regressions (PLSR). The performance of three different instrumental settings (laboratory, field and airborne spectroscopy) has been assessed and their relative advantages for soil monitoring studies have been outlined using the concept of Minimal Detectable Difference. It appears that ground-based spectrometers give Root Mean Square Errors of Cross-Validation similar to the limit of repeatability of a routine SOC analytical technique such as the Walkley and Black method (±1 g C kg−1). The airborne spectrometer, despite its greater potential to cover large areas during a single flight campaign, has some difficulties to reach such values due to a lower Signal-to- Noise Ratio. Because of its statistical nature, the method and its potential rely on the stability of the calibrations obtained. It appears that calibrations are currently site-specific due to variation in soil type and surface condition. However, it is shown that PLSR can take into account both soil and spectral variation caused by different measuring campaigns and study areas. Further research is needed to develop regional spectral libraries in order to be able to use VNIRS as a robust analytical technique for precisely determining the SOC content and its spatial variation. [less ▲]

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See detailStatistical Analysis of the night weather conditions favouring the epidemic of the brown rust in the Grand-Duchy of Luxemburg.
El Jarroudi, Moussa ULg; Tychon, Bernard ULg; Maraite, H. et al

in Italian Journal of Agronomy [=IJA] = Rivista di Agronomia (2008), 3(3), 611-612

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See detailEnvahissement des cuvettes par apports éoliens: processus, impacts et moyens de lutte
Ambouta, Karimou J-M; Tychon, Bernard ULg

in Tropicultura (2008), 26

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See detailAssessing the impact of fungal diseases management on crops and environment. Using dynamic models in the case of foliar diseases in wheat
Bancal, Marie-Odile; Roche, Romain; Gabrielle, Benoit et al

Conference (2007, November 13)

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See detailBulletin agrométéorologique - Situation au 30 septembre 2007
Tychon, Bernard ULg; Schyns, Virginie; Denis, Antoine ULg et al

in Bulletin Agrométéorologique (2007), 6(3), 1-4

Les conditions météorologiques depuis le 20 août dernier, date du dernier bulletin, ont été très proches des conditions normales. Mis à part quelques orages locaux, aucun phénomène météorologique ... [more ▼]

Les conditions météorologiques depuis le 20 août dernier, date du dernier bulletin, ont été très proches des conditions normales. Mis à part quelques orages locaux, aucun phénomène météorologique particulier n’est à signaler. Les rendements satisfaisants à bons annoncés dans le dernier bulletin pour les cultures de maïs, betterave et pomme de terre sont confirmés. [less ▲]

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See detailLaboratory, field and airborne spectroscopy for monitoring organic carbon content in agricultural soils
Stevens, A.; van Wesemael, B.; Tychon, Bernard ULg et al

Conference (2007, October)

This study explains the potential and the limits of a field ASD spectrometer and a CASI airborne instrument to assess the Soil Organic Carbon, in the context of soil carbon mapping.

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See detailBulletin agrométéorologique - Situation au 20 août 2007
Tychon, Bernard ULg; Schyns, Virginie; Denis, Antoine ULg et al

in Bulletin Agrométéorologique (2007), 6(2), 1-4

Les conditions météorologiques depuis le début juillet ont été marquées par des pluies fréquentes et parfois violentes en particulier dans le Nord du pays. Aucun stress hydrique n’est à signaler. Les ... [more ▼]

Les conditions météorologiques depuis le début juillet ont été marquées par des pluies fréquentes et parfois violentes en particulier dans le Nord du pays. Aucun stress hydrique n’est à signaler. Les températures de juillet et août sont restées proches de la normale permettant aux cultures de conserver une certaine avance phénologique acquise au printemps, ce qui laisse globalement augurer de bons rendements pour les cultures de maïs, betteraves et pomme de terre. [less ▲]

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See detailBulletin agrométéorologique - Situation fin juin 2007
Tychon, Bernard ULg; Schyns, Virginie; Denis, Antoine ULg et al

in Bulletin Agrométéorologique (2007), 6(1), 1-4

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