References of "Ozer, Pierre"
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See detailOr bleu / Or noir
BALTHASAR, JEAN PIERRE; COLLIGNON, FABRICE; DE WIT, PIERRE et al

Article for general public (2005)

Au grand mécontentement général, le prix du pétrole augmente irrésistiblement. Malgré cela, notre société ne semble pas disposée à changer ses habitudes. [...] Ces mois de vacances ont été riches en ... [more ▼]

Au grand mécontentement général, le prix du pétrole augmente irrésistiblement. Malgré cela, notre société ne semble pas disposée à changer ses habitudes. [...] Ces mois de vacances ont été riches en catastrophes climatiques. Ainsi, en Afrique de l'Ouest, des milliers de personnes ont disparu suite à une longue famine consécutive à un ciel resté trop longtemps avare en précipitations. En Méditerranée occidentale, on ne compte plus les milliers d'hectares de forêt partis en fumée à cause de la sécheresse. Au même moment, l'Europe centrale et orientale est lasse de patauger dans l'eau. Les spécialistes qualifient ces inondations comme étant les plus graves qu'aient connues la Suisse et la Roumanie. L'Inde est également noyée alors que Taïwan se prépare à la tempête la plus violente de son histoire. Et après ces préliminaires dramatiques, voici Katrina qui sème chaos et désolation. [...] [less ▲]

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See detailBulletin agrométéorologique - Juillet 2005
Tychon, Bernard ULg; Ozer, Pierre ULg; De Longueville, Florence ULg et al

in Bulletin Agrométéorologique (2005), 4(4), 1-5

Le mois de juillet fut anormalement pluvieux en diverses régions du pays. Les autres paramètres climatiques furent néanmoins proches de la moyenne. Les prévisions de rendements des principales cultures ... [more ▼]

Le mois de juillet fut anormalement pluvieux en diverses régions du pays. Les autres paramètres climatiques furent néanmoins proches de la moyenne. Les prévisions de rendements des principales cultures sont globalement à la baisse sur le territoire par rapport à l’année dernière. [less ▲]

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See detailBulletin agrométéorologique - Juin 2005
Tychon, Bernard ULg; Ozer, Pierre ULg; De Longueville, Florence ULg et al

in Bulletin Agrométéorologique (2005), 4(3), 6

Tous les paramètres climatiques furent anormaux à exceptionnels par rapport à la moyenne durant le mois de juin. Aussi, les prévisions de rendements de principales cultures sont globalement à la baisse ... [more ▼]

Tous les paramètres climatiques furent anormaux à exceptionnels par rapport à la moyenne durant le mois de juin. Aussi, les prévisions de rendements de principales cultures sont globalement à la baisse sur le territoire. [less ▲]

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See detailLe G8 ou la Guerre des Mondes
Ozer, Pierre ULg; Balthasar, Jean Pierre

Article for general public (2005)

Les inconditionnels de Steven Spielberg, les passionnés de science fiction et les fans de Tom Cruise comptent les minutes. C'est ce mercredi que sort dans les salles obscures le très attendu « La Guerre ... [more ▼]

Les inconditionnels de Steven Spielberg, les passionnés de science fiction et les fans de Tom Cruise comptent les minutes. C'est ce mercredi que sort dans les salles obscures le très attendu « La Guerre des Mondes » dont les affiches promotionnelles tapissent nos villes depuis deux semaines déjà. La bande annonce nous met en appétit : « Préparez-vous pour un événement qui va changer le monde ». [...] [less ▲]

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See detailLa désertification, cancer environnemental du Sud
Ozer, Pierre ULg

Article for general public (2005)

La désertification, problématique environnementale majeure pour le XXIe siècle, menace constamment près du tiers de la planète. Pourtant l'opinion publique se désintéresse de cette cause et les médias n ... [more ▼]

La désertification, problématique environnementale majeure pour le XXIe siècle, menace constamment près du tiers de la planète. Pourtant l'opinion publique se désintéresse de cette cause et les médias n'accordent que difficilement une petite place à ce sujet alors qu'ils font un large écho aux changements climatiques, à la perte de biodiversité, ou encore aux catastrophes naturelles. [...] [less ▲]

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See detailBulletin agrométéorologique - mai 2005
Tychon, Bernard ULg; Ozer, Pierre ULg; Horion, S. et al

in Bulletin Agrométéorologique (2005), 4(2), 6

Si la situation météorologique est globalement normale en Belgique, dans certaines régions, le manque de précipitations cumulées depuis le début du printemps commence à inquiéter. A ce stade de l’année ... [more ▼]

Si la situation météorologique est globalement normale en Belgique, dans certaines régions, le manque de précipitations cumulées depuis le début du printemps commence à inquiéter. A ce stade de l’année culturale, les prévisions de rendements indiquent le maïs fourrager comme étant la culture la plus touchée par les conditions climatiques qui prévalent depuis plusieurs mois. Par contre, sur le plan national, par rapport à l’année passée, l’orge d’hiver et la pomme de terre Bintje marquent une certaine stabilité, tandis que le froment d’hiver et la betterave sucrière devraient voir leurs rendements légèrement augmenter. [less ▲]

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See detailL’enseignement en gestion des risques naturels
Ozer, Pierre ULg

Article for general public (2005)

D’ici l’an 2025, 80% de la population mondiale résidera dans les pays en développement et, d’après les estimations, pas moins de 60% de cette population sera extrêmement vulnérable aux inondations ... [more ▼]

D’ici l’an 2025, 80% de la population mondiale résidera dans les pays en développement et, d’après les estimations, pas moins de 60% de cette population sera extrêmement vulnérable aux inondations, tempêtes violentes, tremblements de terre, etc. [...] [less ▲]

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See detailBulletin agrométéorologique - Avril 2005
Tychon, Bernard ULg; Ozer, Pierre ULg; De Longueville, Florence ULg et al

in Bulletin Agrométéorologique (2005), 4(1), 1-5

L’hiver météorologique (décembre 2004 à février 2005) peut être caractérisé de normal, tout comme les mois de mars et avril qui lui ont succédé. La situation des cultures d’hiver est également normale ... [more ▼]

L’hiver météorologique (décembre 2004 à février 2005) peut être caractérisé de normal, tout comme les mois de mars et avril qui lui ont succédé. La situation des cultures d’hiver est également normale, avec des rendements qui s’annoncent généralement supérieurs à ceux de 2003 et de 2004 pour le froment d’hiver. Dans le cas de l’orge d’hiver, les estimations de rendements n’atteignent pas les résultats de 2004 mais dépassent largement les rendements observés en 2003. Il est prématuré d’émettre des prévisions pour les cultures printanières. [less ▲]

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See detailTsunami : le reflet du clivage Nord-Sud
Ozer, Pierre ULg

Article for general public (2005)

La vague de dix mètres qui a déferlé sur l'Asie du Sud-Est peu après Noël montre à quel point l'Homme est fragile par rapport aux catastrophes naturelles. En outre, elle met en relief la disparité qui ... [more ▼]

La vague de dix mètres qui a déferlé sur l'Asie du Sud-Est peu après Noël montre à quel point l'Homme est fragile par rapport aux catastrophes naturelles. En outre, elle met en relief la disparité qui existe entre les pays développés et le reste du monde. [...] [less ▲]

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See detailTsunami en Asie du Sud-Est : analyse de son importance dans la presse écrite, des coûts assurés et du nombre de victimes à Sumatra
De Longueville, Florence ULg; Ozer, Pierre ULg

in Bulletin de la Société Géographique de Liège (2005), 46

The tsunami that affected the Indian ocean’s rims on December 26, 2004 claimed close to 300 000 deaths, essentially on the island of Sumatra, Indonesia, which suffered overwhelming devastation. This ... [more ▼]

The tsunami that affected the Indian ocean’s rims on December 26, 2004 claimed close to 300 000 deaths, essentially on the island of Sumatra, Indonesia, which suffered overwhelming devastation. This article is focused on three specific aspects of the disaster. On one side, we analyse the tribune offered to the tsunami catastrophe by the press in Le Soir and Le Monde. On the other side, we present an analysis of the distribution of insured losses from the latest data made available by the two largest reinsurance world companies, Swiss Re and Munich Re. Finally, we try to compare the estimated death toll with available demographic data for the province of Aceh. Here we show that the place given to the tsunami is enormous when compared to other natural tragedies, and we try to explain what motivated such a coverage. In addition, the analysis of insured losses highlights the North-South differences as local victims (99 %) concentrate less than 10 % of the losses supported by insurers. For what regards the death toll, we conclude that the number of about 235 000 for northern Indonesia is a broad estimation and that a realistic approach is impossible since no census was made in this region over the last three decades. [less ▲]

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See detailMise en évidence de la résilience de la végétation sahélienne par télédétection basse résolution au Niger à la suite d’épisodes de sécheresse.
Hountondji, Yvon ULg; Nicolas, Jacques ULg; Sokpon, Nestor et al

in Belgeo (2005), 2005(4), 499-516

In order to identify areas where desertification may have occurred over the last two decades, 109 stations located in three bioclimatic zones of Niger are analyzed. Time series of remote sensing data are ... [more ▼]

In order to identify areas where desertification may have occurred over the last two decades, 109 stations located in three bioclimatic zones of Niger are analyzed. Time series of remote sensing data are well suited to this task. Here, we use time series of NOAA AVHRR normalized difference vegetation index (NDVI) data and rainfall data. In this study, trend analysis is used to identify areas within the biomes from 1981 to 1999 in Niger with apparent land degradation in semi-arid areas. It appears that most of Niger (82,5%) recorded increasing rainfall while only 78,9 % experienced increasing in integrated vegetation index (iNDVI). However, the combination of the two variables through the ratio iNDVI/RR shows a widespread reduction of the rain-use efficiency with highly significant trend for the stations grouped by bioclimatic area (p<10-6) during the studied period (1981-1999). These negative trends suggest a progressive diminution of the vegetation productivity as highlighted by the lowering of the iNDVI/RR ratio. This situation suggested a consistently environmental degradation and that desertification processes continued during the last two decades over most of the Sahelian belt of Niger. [less ▲]

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See detailAnalysis of the vegetation trends using low resolution remote sensing data in the Sahel (1982-1999) for the monitoring of desertification
Hountondji, Yvon ULg; Sokpon, Nestor; Ozer, Pierre ULg

in Röder, Achim; Hill, Joachim (Eds.) Abstract Book - Remote Sensing and Geoinformation Processing in the Assessment and Monitorinf of Land Degradation and Desertification (2005)

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See detailAnalyse des inondations en aval du barrage de Nangbeto sur le fleuve Mono (Togo et au Bénin).
Ago, Expédit Evariste ULg; Petit, François ULg; Ozer, Pierre ULg

in Geo-Eco-Trop (2005), 29

The analysis of risk of flood downstream from the hydroelectric dam of Nangbeto in the Mono River was about the survey of interannual variability of rainfall and rivers flows from 1955 to 1999, the ... [more ▼]

The analysis of risk of flood downstream from the hydroelectric dam of Nangbeto in the Mono River was about the survey of interannual variability of rainfall and rivers flows from 1955 to 1999, the population vulnerability, the hydrological modification and the impacts downstream in Togo and Benin from the dam constructed in 1987. The analysis of the mean annuel discharge has revealed no tendency, showing thus that the change of land use, the increase of waterproof areas and even the functioning of the hydroelectric dam have not modified in a significant manner the river's rate of flow. Apart from the return to the improvement in rainfull as far back as the end of years 80, the anthropic pressure and the demographic explosion have best explained the magnitude and frequency of flooding downstream from the hydroelectric dam of Nangbeto. The soil degradation, the deforestation of the floodplain, the increase in the number of human settlements in the river boundary increases the vulnerability of population faced with flooding. [less ▲]

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See detailMonitoring of the 2003 summer drought in Belgium with the NDWI applied on spot-vegetation data.
Horion, Stéphanie; Eerens, Herman; Tychon, Bernard ULg et al

in Veroustraete, F.; Bartholomé, E.; Verstraeten, W. W. (Eds.) Proceedings of the 2nd international vegetation user conference. 1998-2004 : 6 years of operational activities. (2005)

The summer 2003 was abnormally hot, sunny and dry. The average temperatures from June to August were the highest ever recorded in the Belgian reference meteorological station of Uccle, but also in other ... [more ▼]

The summer 2003 was abnormally hot, sunny and dry. The average temperatures from June to August were the highest ever recorded in the Belgian reference meteorological station of Uccle, but also in other countries of western and central Europe such as Portugal, Germany, Switzerland and the United Kingdom. Many human activities were affected by these particular climatic conditions, among which agriculture.The Normalized Difference Water Index (NDWI) applied on ten-daily SPOT- VEGETATION imagery is one of the drought indicators which could serve for the localisation of drought affected areas in Belgium. In this paper preliminary results show that detection of dry events is possible using historical averages of NDWI. Relative NDWI images can be used to monitor the development of the summer drought.These images are computed by the weighted difference between the NDWI values during this summer and its value at the same period in a reference year, which corresponds to a normal year in terms of rainfall availability. Analysis of the relation between NDWI and NDVI behaviours show that the green biomass influences the NDWI value especially during the growing season. More accurate study has to be done to individualize the specific NDWI behaviour during dry events. In perspectives, index validation with meteorological parameters and with the Relative Soil Moisture Index, which is an output of the Belgian Crop Growth Monitoring System, will improve this study. [less ▲]

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See detailAeolian dust falls in northern Italy in autumn 1996: chemical and mineralogical comparison
Ozer, Pierre ULg; LUCCHETTI, Gabriella

in Periodico di Mineralogia (2005), 74(2), 103-116

This paper describes two dust fall events in Genoa and Turin (northern Italy) on 12 November 1996 and 7 December 1996 respectively. Meteorological data suggest that the dust-bearing rain that fell on ... [more ▼]

This paper describes two dust fall events in Genoa and Turin (northern Italy) on 12 November 1996 and 7 December 1996 respectively. Meteorological data suggest that the dust-bearing rain that fell on Genoa originated in north-eastern Morocco, where dust mobilisation was reported two days earlier, and had been carried straight to the north-western Italian coast by very strong winds. But the dust fall observed in Turin was not characterised by any specific synoptic situation inducing dust transport from the southern Mediterranean. The analyses include a quantitative and a qualitative study of two dust samples collected in downtown Genoa and Turin. The total amounts of dust that fell give two very high values of 4.05 g m-2 for Genoa and 0.54 g m-2 for Turin. The median sizes of the dust particles were 14.6 µm and 25.8 µm respectively. Most of the dust material collected in Genoa showed a yellowish-brown to red colour due to surface weathering by ferric hydroxides, and was sometimes coated with clayey particles. This attests to the Saharan origin of the particles. On the contrary, only 15% of the material sampled in Turin was coated with red-like clayey material from the desert. A large part of the sample was covered with a carbon-like substance. In addition, the proportion of organic matter (pollen grains and seeds) and anthropogenic fibrous material was much higher. This suggests that the dust fall observed in Turin very likely originated from local pollution mixed with a low proportion of long-distance Saharan dust. [less ▲]

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See detailDésertification au Sahel : Crise climatique ou anthropique ?
Ozer, André ULg; Ozer, Pierre ULg

in Bulletin des Séances de l’Académie Royale des Sciences d’Outre-Mer = Mededelingen der Zittingen van de Koninklijke Academie voor Overzeese Wetenschappen (2005), 51(4), 395-423

Over the last decades, the Sahel suffered two dramatic contiguous droughts. At present, and since the early 1990s, rainfalls have recorded an amelioration that tends towards the average of precipitation ... [more ▼]

Over the last decades, the Sahel suffered two dramatic contiguous droughts. At present, and since the early 1990s, rainfalls have recorded an amelioration that tends towards the average of precipitation previous to the 1970s. However, this improvement may be due to increasing rainfall intensity and it seems that the length of the rainy season did not show any extension when compared to the 1970s and 1980s. Moreover, the Sahelian population has been multiplied by 3 since 1950 and is foreseen to be multiplied by 10 by the second half of the 21st century. Increasing urban population levels are much more impressive and bring about important environmental disruptions every day. Such increasing human pressure leads to uncontrolled deforestation in order to meet the needs in fuel wood, wood for construction and shifting cultivation. In addition, the ever-increasing number of herds for contracting range conditions leads to overgrazing. All these processes cause the degradation of the vegetation cover, a constant diminution of crop yields, as well as a strong reduction of biodiversity. One of the consequences is the reactivation of previously fixed dunes that were formed during the last interpluvial phase (18,000 BP). This article provides a state-of-the-art of the present controversy about desertification processes and concludes that if the droughts of the 1970s and 1980s have had dramatic consequences for the population of the Sahel, current and coming increasing human pressure will intensify the desertification of the southern fringe of the Sahara. [less ▲]

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See detailEstimation de la pollution particulaire naturelle de l’air en 2003 à Niamey (Niger) à partir de données de visibilité horizontale
Ozer, Pierre ULg

in Environnement Risques & Santé (2005), 4(1), 43-49

There is no longer any question that air pollution in the form of large quantities of total suspended particulates (TSP) and particulate matter less than 10 µm in aerodynamic diameter (PM 10) harms human ... [more ▼]

There is no longer any question that air pollution in the form of large quantities of total suspended particulates (TSP) and particulate matter less than 10 µm in aerodynamic diameter (PM 10) harms human health. Deterioration in air quality due to high concentrations of mineral dust from Africa affects the US and Europe, although most of these countries are far from the Sahara. Surprisingly, no estimates of TSP or PM 10 levels near the Saharan dust source are available. Measurements taken at Niamey-Airport in Niger of horizontal visibility, which is reduced by the presence of dust in the atmosphere, allowed us to estimate TSP and PM 10 levels according various relations found in the literature. Both the magnitude and frequency of mineral particle concentrations are very high. The average yearly concentration is estimated at 103 µg.m -3 TSP and 67 µg.m -3 PM 10. These very high particulate levels present a real public health threat to which national and international policy-makers must respond. [less ▲]

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See detailAnalyse climatique de la région de Gouré, Niger oriental : récentes modifications et impacts environnementaux
Ozer, Pierre ULg; Bodart, Catherine ULg; Tychon, Bernard ULg

in Cybergeo : Revue Européenne de Géographie = Cybergeo - European Journal of Geography (2005)

Since the late 1960s, the Sahel is affected by a dramatic drought. This article analyses climatic variations recorded in the Gouré area, eastern Niger, between 1936 and 2003. It appears that the drought ... [more ▼]

Since the late 1960s, the Sahel is affected by a dramatic drought. This article analyses climatic variations recorded in the Gouré area, eastern Niger, between 1936 and 2003. It appears that the drought ended in the late 1980s. However, the rainfall increase did not lead to an extension of the length of the rainy season. The study of the wind shows that correct data were recorded during the two first years of the station of Gouré (1984 and 1985). Afterwards, wind speed was entached by errors and did not report since 1997. The situation is alarming as we know that neighbouring stations meet the same problems and that no synoptic station currently reports wind values in eastern Niger. However, based on wind speed and deflation data recorded in 1984, a threshold wind speed of 7 m/s was determined in Gouré. Finally, from measurements of horizontal visibility reduced by mineral dust, our results suggest that air quality is reduced because of the high frequency of wind erosion. The confrontation of our results with recent environmental studies in that region show that the end of the drought did not lead to any landscape improvement. Increasing human pressure tends to be the main driving factor of land degradation. [less ▲]

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See detailEvolution des ressources forestières en Afrique de l’Ouest soudano-sahélienne au cours des 50 dernières années
Ariori, Serge Léopold; Ozer, Pierre ULg

in Geo-Eco-Trop (2005), 29

On the basis of an exhaustive consultation of the literature describing the temporal evolution of land cover in arid, semiarid and dry subhumid regions of West Africa, this study shows that the ... [more ▼]

On the basis of an exhaustive consultation of the literature describing the temporal evolution of land cover in arid, semiarid and dry subhumid regions of West Africa, this study shows that the deforestation trend has been very important during the second half of the 20th century. This trend to deforestation is globally large (2% per year) and is clearly alarming. Although our results differ from FAO's official data, it is demonstrated that those are questionable. In addition, if dense woody formations have been strongly reduced in the study area, our study indicates that degraded woody formations are currently declining. Our results clearly go against the recent conclusions of some authors preaching the idea of a 'greening Sahel'. [less ▲]

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See detailMesure des retombées au sol des aérosols désertiques durant l’hivernage 2005 à Mâle, Mauritanie méridionale.
Gassani, Jean; Bent Mohamed, Aminetou; Duchesne, Jean et al

in Geo-Eco-Trop (2005), 29

The Sahara and its margins largely contribute to the global injection of mineral dust into the northern hemisphere, about half of the yearly global mineral dust production. In this study, we have placed a ... [more ▼]

The Sahara and its margins largely contribute to the global injection of mineral dust into the northern hemisphere, about half of the yearly global mineral dust production. In this study, we have placed a pyramidal receptacle in Mâle (southern Mauritania) during the rainy season 2005 in order to measure daily Saharan dust deposition. The dust quantity collected totals 78.38 g/m2 during the 3 months experimented. Comparing our results to previous works achieved in the southern border of the Sahara shows that the levels of deposition in Mâle are extremely high. This could suggest a continuous environmental degradation resulting from always increasing human pressure. [less ▲]

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