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See detailRecent precipitation and temperature changes in Djibouti City
Ozer, Pierre ULg; Mahamoud, Ayan

Conference (2012, May 29)

A dataset of derived indicators has been compiled to clarify whether the frequency and / or the severity of rainfall and temperature extremes changed over the last decades in the city of Djibouti in East ... [more ▼]

A dataset of derived indicators has been compiled to clarify whether the frequency and / or the severity of rainfall and temperature extremes changed over the last decades in the city of Djibouti in East Africa. This study uses the only current available coverage of homogenous daily series which can be used for calculating any significant change in rainfall and temperature in recent years. It covers the 1980–2011 period for precipitation and the 1966–2011 period for what regards maximum, minimum and mean temperature. We used a set of 23 indicators of extreme climatic events. Results show that the annual total precipitation, the annual total of wet days (with daily rainfall >= 1mm) and the frequency of very wet days (defined as the 95th percentile) have strongly declined over the last 32 years. Yet, since 2007, mean yearly rainfall meets a 73% deficit when compared to the 30-year average, a situation that is much worst than what was observed in the early 1980s. For what regards temperatures, the average increase recorded during the 1966–2011 period is of +0.28°C per decade, a far higher value than the global rising temperature. Heatwaves characterized by daily maximum temperatures ≥ 45°C (that is the 99th percentile) have become 15 times more frequent than in the past (comparing the 1966–75 and 2002–2011 periods) while extremely cool nights (<18.7°C, that is the 1st percentile in minimum temperature) have almost disappeared. Although the database should be extended to improve the global picture of recent climate changes in Djibouti, it seems very likely that rainfall shortages and increasing temperature extremes have already impacted the people of the Republic of Djibouti, especially the water availability and health sectors. Adaptation strategies are urgently needed since the global warming process is not likely to decline in the next decades. [less ▲]

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See detailClimat: nous n'avons pas de temps à perdre
Berger, A; Callens, I; Bouckaert, T et al

Article for general public (2012)

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See detailEnergie et climat : historique et perspectives
Ozer, Pierre ULg

in La ville : air, eau, terre, feu. Éléments pour un Plan Régional de Développement Durable économe en ressources (2012)

On le sait, la Conférence de Copenhague a été un échec. En effet, quelques chefs d'Etat –à savoir les européens et américains pour le monde industrialisé– et la Chine, l'Inde, le Brésil et l'Afrique du ... [more ▼]

On le sait, la Conférence de Copenhague a été un échec. En effet, quelques chefs d'Etat –à savoir les européens et américains pour le monde industrialisé– et la Chine, l'Inde, le Brésil et l'Afrique du Sud pour les pays émergents ont doublé le processus de négociations des Nations Unies (dans l'obscurantisme le plus total et sans concertation avec les pays en développement) pour arriver à une note qui tient sur deux pages. Ce texte ne comporte plus de trace d'engagement de réduction de GES pour 2020 ou 2050, pas même volontaire. Une aide financière sera dégagée pour aider les pays pauvres à faire face aux conséquences du changement climatique. Quel sera le montant de cette aide ? Sera-t-elle additionnelle ou détournée des fonds d'aide au développement ? De qui viendra-t-elle et à qui profitera-t-elle ? Et pour quoi faire ? Nul ne le sait. Quant à la réduction de la déforestation et aux contraintes d'émissions de GES pour les secteurs aérien et maritime (annoncés comme des conditions sine qua non d'accord par les européens), pas un mot... Autant dire que le résultat final de ce grand rendez-vous n'est guère étincelant... Directement après ladite Conférence, j’écrivais dans une carte blanche « A quoi sert la science, si le politique se borne à cultiver, pour des raisons économiques dans le court terme, la science de l'inconscience ? » (Ozer 2010). Arriverons-nous à trouver un accord dans les mois ou les années à venir ? Ou devrons-nous subir brutalement les conséquences de ce changement climatique ? Car on peut négocier à l’infini entre délégations, mais on ne négociera jamais avec la physique de l’atmosphère. [less ▲]

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See detailLand Cover Dynamics (1990-2002) in Binh Thuan Province, Southern Central Vietnam
Hountondji, Yvon ULg; de Longueville, Florence; Ozer, Pierre ULg

in International Journal of Asian Social Science (2012), 2(3), 336-349

This paper describes the use of satellite imageries and GIS data for identifying key environmental characteristics of Binh Thuan Province in south central Vietnam and for detecting the major changes ... [more ▼]

This paper describes the use of satellite imageries and GIS data for identifying key environmental characteristics of Binh Thuan Province in south central Vietnam and for detecting the major changes patterns within this region. Landsat TM (1990) and Landsat ETM+ (2002) imageries were used to classify the study area into seven land use and land cover (LULC) classes. A post-classification comparison analysis was used to quantify and illustrate the various LULC conversions that took place over the 12-year span of time. Results showed that a steady growth in population has caused extensive changes of land cover throughout the area. The maps also indicate that the loss of woody land (forest) and the extension of wetlands (irrigated area), combined with built-up encroachment, remains one of the most serious environmental problems facing the Binh Thuan Province today. The post-classification change detection analysis showed that critical habitats accounted for nearly 38.5% of the intensive study area between 1990 and 2002 while 61.5% remained stable. Results also showed over the 12-year span, approximately 1151.2 km² (115.120 ha) forest were converted respectively to brush, irrigated area (wetlands), cropland and built-up. This is an overall average decrease of 9594 hectares of forested area per year. Throughout the study area, districts most affected by forest conversion to another land cover are: Bac Bihn (2798 ha/year), Than Linh (2717 ha/year), Ham Thuan Nam (1601 ha/year) and Ham Thuan Bac (1524 ha/year). Based on the identified causes of these changes, we made policy recommendations for better management of land use and land cover. [less ▲]

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See detailImpact of global climate change and desertification on the environment and society in Southern Centre of Vietnam (a case study in Binh Thuan province). Climate today and tomorrow: state of play and perception.
Ozer, Pierre ULg

Report (2012)

The Province of Binh Thuan is the driest area of Vietnam. It is felt as being affected by desertification processes that are mainly resulting from the ongoing „climate change‟, especially shortening ... [more ▼]

The Province of Binh Thuan is the driest area of Vietnam. It is felt as being affected by desertification processes that are mainly resulting from the ongoing „climate change‟, especially shortening rainfall. But has climate, and especially precipitations, really changed in recent years? Or is the recent increase of agricultural activities with higher water needs may explain such perception of a changing climate? In the collection of four papers presented hereafter, we try to answer to these questions. Yet, the first paper investigates recent trends in precipitation and temperatures using daily data from the weather station of Phan Thiet. It appears that the area did not experience any significant precipitation decrease (rainfall have, at the contrary, globally increased) but a very significant increase in temperature. The second paper focuses on future climate projections (that is 2046-2065 and 2081-2100 compared to historical data 1970-1999). It shows that the Province of Binh Thuan will face an increase of mean temperature of about 1.6°C (over 2046-2065) and 2.5°C (over 2081-2100) and an increase of extreme temperatures and extreme rainfall events. However, no significant changes about the evolution of the annual amount of precipitation were found. It also indicates that the dry season is likely to be longer in 2046-2065 owing to a delay in the onset of the rainy season (up to 15 days) accompanied by an earlier end of the rainy season (up to 30 days). The third paper explores recent land use and land cover changes in the Province of Binh Thuan. Comparisons of the land cover maps reveal that a steady growth in population has caused extensive changes of land cover throughout the area. The maps also indicate that the loss of woody land (forest) and the extension of irrigated area, combined with built-up encroachment, remains one of the most serious environmental problems today. Yet, results showed over the 12-year span, approximately 115,120 ha of forests were converted respectively to brush, irrigated area, cropland and built-up. This is an overall average decrease of approximately 9,594 ha of forested area per year. Based on the identified causes of these changes, we made policy recommendations for better management of land use and land cover. Such results show that water needs are always increasing due to the extension of irrigated areas. The last paper concludes with a case study of a fishing village disappearing as a result of shoreline erosion. It shows that the term “climate change” is misused probably because it is easier to blame a global issue rather than the local mismanagement of natural resources, the lack of land use planning and the nonexistence of policies focused on natural hazard management in the uncontrolled construction the seaside resort of Mui Ne. This reflexion about the wrong perception of climate change which may cause several economic problems could be extended to water availability which may not be sufficient to support recent developments of irrigated agriculture. Understanding current problems may help developing adaptation strategies in the next decades. Further research is needed to understand such perception of climate change, especially when knowing that future climate may be really affected by an increase of extreme rainfall events and an extended dry season. [less ▲]

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See detailChangement climatique: Etat des lieux 2012
Ozer, Pierre ULg

Scientific conference (2012, January 30)

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See detailCLIMAT: DES BOULEVERSEMENTS CONSTATES (2012)
Ozer, Pierre ULg

Scientific conference (2012, January 17)

17 janvier 2012 : Climat, des bouleversements constatés Docteur en géographie à l’Université de Liège, spécialisé sur les problèmes liés à la désertification, aux catastrophes naturelles et à leur gestion ... [more ▼]

17 janvier 2012 : Climat, des bouleversements constatés Docteur en géographie à l’Université de Liège, spécialisé sur les problèmes liés à la désertification, aux catastrophes naturelles et à leur gestion, et à de nombreux aléas climatiques, Pierre OZER exposera l’évolution du climat, en faisant le lien entre les travaux du GIEC (Groupe d’experts Intergouvernemental sur l’Evolution du Climat) et de l’UNFCCC (Convention Cadre des Nations Unies sur les Changements Climatiques). A travers cette démonstration il montrera le poids de ces travaux au cours des négociations internationales (passées, actuelles et à venir). [less ▲]

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See detailChangement climatique, géomorphologie littorale, désertification
Ozer, Pierre ULg

Learning material (2012)

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See detailIs the fishing village of Phan Thiet victim of climate change ?
Ozer, Pierre ULg

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2012), 36

Warming of the climate system is unequivocal, as it is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average ... [more ▼]

Warming of the climate system is unequivocal, as it is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level. In this framework, sea level rise is virtually certain. This will impact ecosystems, coastal areas, human health, and economies. Vietnam is very likely to be one of the most affected countries with its 3200 km of shorelines with amplified vulnerability in large areas already affected by subsidence such as the Mekong and Red River deltas. In January 2009, international broadcast news have relayed the information that 27 houses located on the southern coast of Vietnam, in the fishing village of Phan Thiet, 200 km east of Ho Chi Minh City, have collapsed and that another hundred buildings were also threatened of destruction. According to experts, this event was definitely one of the consequences of global warning. This article shows, using the multi dates of Google Earth, that this assumption is not correct and highlights the real causes of this rapid and inevitable retreat of the coastline in this village, namely the mismanagement of natural resources, the lack of land use planning and the non-existence of policies focused on natural hazard management in the uncontrolled construction the seaside resort of Mui Ne, a few kilometers east. [less ▲]

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See detailEvolution des caractéristiques pluviométriques dans la zone urbaine de Butembo (RDC) de 1957 À 2010
Sahani, Muhindo; Moeyersons, Jan; Vandecasteele, Ine et al

in Geo-Eco-Trop : Revue Internationale de Géologie, de Géographie et d'Ecologie Tropicales (2012), 36

In recent years, the city of Butembo faced unprecedented damaging floods. This study aims to analyze the rainfall variations recorded at the meteorological station of the Agricultural and Veterinary ... [more ▼]

In recent years, the city of Butembo faced unprecedented damaging floods. This study aims to analyze the rainfall variations recorded at the meteorological station of the Agricultural and Veterinary Technical Institute (ITAV) in Butembo between 1957 and 2010. It appears that rainfall features have remained relatively stable over the analyzed period.Linear upward trends were observed for the simple day intensity index (SDII) and for the total number of days characterized by precipitation >= 10 mm (P10). In contrast, seven other rainfall indices recorded a decreasing trend: the total annual precipitation (PTOT), the total number of wet days (rainfall >=1 mm) (JP), the total number of days characterized by precipitation >= 20 mm (P20), the maximum daily rainfall (Px1J), the frequency of intense (P95p), extreme (P99p) and very extreme (P99,5p) rainfall. However, none of these trends were statistically significant. Although the floods recurrence became prevalent, the study reports that extreme rainfall events do not reveal exceptional rains in the past few years. Yet, all recent maximum daily rainfalls are considered as normal since their return period is less than six years. This suggests a significant increase in flood risk mainly due to human impacts over the urban area and increasing vulnerability. This study also underlines that the length of the rainy season is shortening, undermining urban agriculture production and therefore food security. [less ▲]

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See detailKinshasa en proie à l’érosion en ravine : inventaire cartographique et impact socioéconomique
Makanzu, Fils; Ozer, Pierre ULg; Moeyersons, Jan et al

in Colloque international "Géomatique et gestion des risques naturels" en hommage au Professeur André Ozer - Livre de résumés (2012)

Kinshasa, l’une des grandes villes de l’Afrique subsaharienne, a vu sa population passer de 404173 habitants en 1957 à près de 8 millions d’habitants en 2007, soit une augmentation d’environ 20 fois en 50 ... [more ▼]

Kinshasa, l’une des grandes villes de l’Afrique subsaharienne, a vu sa population passer de 404173 habitants en 1957 à près de 8 millions d’habitants en 2007, soit une augmentation d’environ 20 fois en 50 ans seulement. La ville s’est entre-temps agrandie, s’étalant de 94 à 443 km² au cours de la même période. A l’aide de la télédétection et d’un SIG, les ravins d’au moins 5 mètres de large ont été cartographiés à partir d’un couple stéréoscopique SPOT 2006/2007 dans la haute ville de Kinshasa. Cet inventaire a permis la détermination de 308 ravins totalisant une longueur cumulée de 95 km qui occupent une superficie de 2 km² et dont la profondeur moyenne et la largeur moyenne sont respectivement de 7 et 21 mètres. La densité de ravinement est de 0,4 km/km². En imperméabilisant le sol et en concentrant de grandes quantités d’eau de ruissellement, l’urbanisation a modifié le drainage naturel du sol et a augmenté l’aléa dans cette région où il existait déjà. Elle serait donc la cause principale de l’érosion en ravine qui déchire les versants sableux de Kinshasa. [less ▲]

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See detailNon, le village de pêcheurs de Phan Thiet n’a pas été victime du changement climatique
Ozer, Pierre ULg

in Colloque international "Géomatique et gestion des risques naturels" en hommage au Professeur André Ozer - Livre de résumés (2012)

En janvier 2009, 27 maisons situées sur le littoral sud du Vietnam, dans la ville de Phan Thiet, zone très touristique à 200 kilomètres à l'est de Ho Chi Minh-Ville, se sont effondrées. Une centaine d ... [more ▼]

En janvier 2009, 27 maisons situées sur le littoral sud du Vietnam, dans la ville de Phan Thiet, zone très touristique à 200 kilomètres à l'est de Ho Chi Minh-Ville, se sont effondrées. Une centaine d'autres bâtiments étaient également menacés de disparition. Les médias internationaux ont ainsi relayé l’information « des centaines de soldats, de gardes côtes et de volontaires ont été mobilisés pour amasser des sacs de sable sur place et tenter de limiter les dégâts. En cause, l'érosion du littoral, grignoté par de fortes vagues. Selon les experts, le Vietnam et ses plus de 3.200 km de côtes font partie des zones les plus exposées aux effets du réchauffement climatique, qu'il s'agisse de l'élévation du niveau des mers ou de l'augmentation de la fréquence des typhons et inondations ». Il s’agit donc indéniablement d’une des conséquences du réchauffement climatique. Cet article montre comment, en utilisant la fonction multi dates Google Earth, il est possible de démonter cette argumentation et de mettre en évidence les vraies causes de ce rapide et inéluctable retrait des côtes au niveau de ce village de pêcheurs, à savoir la construction anarchique de la station balnéaire de Mui Ne, quelques kilomètres à l’est. La création de ce désormais haut lieu touristique est extrêmement récente, le premier établissement étant sorti de terre en 1994. Vu le succès croissant des plages de sable blanc, toute la côte a depuis été lotie sur près de cinq kilomètres. Mui Ne a donc modifié son espace pour accueillir les touristes occidentaux. Ainsi, les cocoteraies ont été abattues pour laisser la place à des cocotiers ne faisant plus office que de décor sur la plage, les liserons des sables ont été arrachés pour éloigner les puces de mer, le sable a été égalisé et les infrastructures hôtelières ont recouvert les dunes pour être en contact direct avec la plage. C’est ainsi tout un décor « exotique » qui est créé pour être conforme aux représentations des touristes occidentaux. La suite est connue d’avance : le fragile équilibre littoral est rompu et le bilan sédimentaire devient négatif. Entre 2006 et 2009, la plage d’une trentaine de mètres a totalement disparu. Or, la plage étant la raison d’être de ce lieu, il convient de la préserver à tout prix. Ainsi, les promoteurs immobiliers ont eu recours à la construction d’épis de plus de 100 mètres pour recréer de longues plages, artificielles cette fois, qui interrompent le transit sédimentaire. La dérive littorale est ainsi stoppée ce qui engendre la disparition des plages suivantes et l’effondrement des maisons de pêcheurs. Cette analyse montre clairement la rapide modification des paysages qui résulte d’une conversion économique locale non encadrée répondant aux processus de mondialisation. [less ▲]

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See detailCélébrer Noël en investissant dans des choses qui ont du sens
Ozer, Pierre ULg; Perrin, Dominique ULg

Article for general public (2011)

Le contexte de crises financière et environnementale préoccupantes que nous traversons devrait nous convaincre de modifier nos comportements d’achat. Les fêtes de fin d’année peuvent être l’occasion de ... [more ▼]

Le contexte de crises financière et environnementale préoccupantes que nous traversons devrait nous convaincre de modifier nos comportements d’achat. Les fêtes de fin d’année peuvent être l’occasion de consommer différemment, en considérant d’abord la « valeur » des choses avant leur « prix ». [less ▲]

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See detailProcessus de désertification
Ozer, Pierre ULg

Learning material (2011)

Le cours fait le point sur la controverse actuelle qui entoure les processus de désertification et reprend, point par point, certains processus dirigeant la dégradation environnementale dans les zones ... [more ▼]

Le cours fait le point sur la controverse actuelle qui entoure les processus de désertification et reprend, point par point, certains processus dirigeant la dégradation environnementale dans les zones arides, semi-arides et subhumides sèches de la planète en décortiquant les variations climatiques et les activités humaines. [less ▲]

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See detailLe Noël du peuple
Ozer, Pierre ULg

Article for general public (2011)

Un changement est en marche. On sent les frémissements d'un renouveau des mentalités et des comportements en matière d'achats et de consommation, d'empreinte écologique et de modèle social et économique ... [more ▼]

Un changement est en marche. On sent les frémissements d'un renouveau des mentalités et des comportements en matière d'achats et de consommation, d'empreinte écologique et de modèle social et économique vers lequel nous tendons. Soyons acteurs d'une autre société. Pour les fêtes aussi, manifestons nos valeurs. [less ▲]

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See detailThe tsunami in South-East Asia – a retrospective analysis of the management of an apocalyptic natural disaster
Ozer, Pierre ULg; de Longueville, Florence

in Cybergeo : Revue Européenne de Géographie = Cybergeo - European Journal of Geography (2011)

The tsunami that affected the coasts of the Indian ocean on December 26, 2004 claimed close to 226 000 lives, mainly on the island of Sumatra, Indonesia, which suffered overwhelming devastation. This ... [more ▼]

The tsunami that affected the coasts of the Indian ocean on December 26, 2004 claimed close to 226 000 lives, mainly on the island of Sumatra, Indonesia, which suffered overwhelming devastation. This article asks whether a tsunami warning system is needed in the Indian Ocean, where the probability of experiencing a similar catastrophe is very small. In addition, other alternatives, including land use planning and education focused on tsunami risk management, are presented. Their application could considerably reduce financial and human losses if a disaster of this nature was to occur again. [less ▲]

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See detailModifications environnementales et santé publique
Ozer, Pierre ULg

Learning material (2011)

Le cours aborde un aspect des impacts des activités anthropiques sur l’environnement : la problématique du changement climatique. Il en justifie l’importance d’une part car elle résulte d’un long ... [more ▼]

Le cours aborde un aspect des impacts des activités anthropiques sur l’environnement : la problématique du changement climatique. Il en justifie l’importance d’une part car elle résulte d’un long processus de dégradation environnementale et, d’autre part, car ses effets sont globaux et se font déjà ressentir partout dans le monde (vagues de chaleur, événements pluviométriques extrêmes, sécheresses, etc.). En fonction du degré de vulnérabilité de nos sociétés, ces effets affectent notamment le domaine de la santé publique, d’autant plus qu’il est désormais acquis que la tendance ne pourra être renversée dans les prochaines décennies, quoi que nous fassions. Le cours explore les effets de ces stress climatiques sur nos sociétés et les différentes réponses internationales qui sont apportées pour tenter d’y remédier. [less ▲]

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See detailTrends in extreme rainfall events in Benin (West Africa), 1960-2000
Hountondji, Yvon ULg; de Longueville, Florence; Ozer, Pierre ULg

in Proceedings of the 1st International Conference on Energy, Environment and Climate Change (2011, August 26)

Global dataset of derived indicators has been compiled to clarify whether the frequency and / or the severity of rainfall extremes changed during the 1960 – 2000 period in the Republic of Benin in West ... [more ▼]

Global dataset of derived indicators has been compiled to clarify whether the frequency and / or the severity of rainfall extremes changed during the 1960 – 2000 period in the Republic of Benin in West Africa. This period provides the best spatial coverage of homogenous daily series, which can be used for calculating the proportion of global land area exhibiting a significant change in extreme or severe rainfall. We selected 12 indicators of extreme climatic events that are based on daily totals of precipitation. The six first indicators are the annual total precipitation (RTOT); the annual total of wet days (with daily rainfall >= 1mm, Rd); the simple day intensity index (SDII) calculated as the average rainfall from wet days; the annual maximum rainfall recorded during 1, 5, and 30 days (Rx1d, Rx5d, and Rx30d). The other six indices are based on the 95th and 99th percentiles calculated from the daily rainfall data over the 1961-1990 period, that is the 30-year period required by the World Meteorological Organization (WMO) for the calculation of normals. The 95th percentile defines a very wet day. The 99th percentile corresponds to an extreme rainfall event. Based on these percentiles, three extreme precipitation indices were chosen. Very wet day and extreme rainfall frequency are based on the annual count of days with rainfall >= 95th and 99th percentiles of 1961-1990 (R95p and R99p). Very wet day and extreme rainfall intensity corresponds to the annual total precipitation recorded from days with rainfall >= 95th and 99th percentiles of 1961-1990 (R95pSUM and R99pSUM). Very wet day and extreme rainfall proportion is the percentage of the annual total precipitation recorded from days with rainfall >= 95th and 99th percentiles of 1961-1990 (R95pTOT and R99pTOT) and measures how much of the total rain comes from very wet or extreme events. Only time series which had complete records from 1960 to 2000 were used. A total of 21 stations time series were extracted from national climate archives and collated into the unique dataset described here. National maps showing trends during the 1960-2000 period were produced. Results show that only the annual total precipitation, the annual total of wet days and the annual maximum rainfall recorded during 30 days present a significant decreasing trend while the other nine rainfall indicators appear to remain stable. These results are important findings for Benin since scarce works realized in neighbouring regions of West Africa describe a situation more prone to increases in extreme rainfall (in Nigeria [1]) or the opposite (in Guinea Conakry [2] and in Niger [3]) in a similar context of a clear reduction in the yearly precipitation amount. We call for further research on this topic in West Africa since water management is a major tool for sustainable development and poverty alleviation. [1] M. New, B. Hewitson, D.B. Stephenson, et al., “Evidence of trends in daily climate extremes over southern and West Africa,” J. Geophys. Res., vol. 111, 2006, D14102, doi:10.1029/2005JD006289. [2] E. Aguilar, A. Aziz Barry, M. Brunet, et al., “Changes in temperature and precipitation extremes in western central Africa, Guinea Conakry, and Zimbabwe, 1955–2006,” J. Geophys. Res., vol. 114, 2009, D02115, doi: 10.1029/2008JD011010. [3] P. Ozer, Y.C. Hountondji, O. Laminou Manzo, “Evolution des caractéristiques pluviométriques dans l’est du Niger de 1940 à 2007,” GEO-ECO-TROP, Vol. 33, pp. 11-30, 2009. [less ▲]

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See detailLand use and land cover change analysis 1990-2002 in Binh Thuan Province, south central Vietnam
Hountondji, Yvon ULg; Ozer, Pierre ULg

in Proceedings of the 1st International Conference on Energy, Environment and Climate Change (2011, August 26)

Describing the nature and extent of land resources and changes over time has become increasingly important, especially in developing countries. In this study, two Landsat satellite image scenes were ... [more ▼]

Describing the nature and extent of land resources and changes over time has become increasingly important, especially in developing countries. In this study, two Landsat satellite image scenes were examined to identify land use and land cover changes in Binh Thuan province (Vietnam) between 1990 and 2002. Classification accuracies were based upon ground truth data obtained by global positioning system and field collection. A post-classification comparison analysis was used to identify areas that have experienced conversions in land use and land cover. Comparisons of the land cover maps reveal that a steady growth in population has caused extensive changes of land cover throughout the area. The maps also indicate that the loss of woody land (forest) and the extension of wetlands (irrigate area), combined with built-up encroachment, remains one of the most serious environmental problems facing the Binh Thuan Province today. The post-classification change detection analysis showed that critical habitats accounted for nearly 38.5% of the total intensive study area between 1990 and 2002 while 61.5% remained stable. Results also showed over the 12-year span, approximately 1151.2 km² (115.120 ha) forest were converted respectively to brush, irrigated area (wetlands), cropland and built-up. This is an overall average decrease of approximately 9594 hectares of forested area per year. Throughout the study area, districts most affected by forest conversion to another land cover are: Bac Bihn (2798 ha/year), Than Linh (2717 ha/year), Ham Thuan Nam (1601 ha/year) and Ham Thuan Bac (1524 ha/year). Based on the identified causes of these changes, we made policy recommendations for better management of land use and land cover. [less ▲]

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See detailAssessment of wind energy potential in Niamey, Niger
Garba Abdou, Mahamadou; Ozer, Pierre ULg

in Proceedings of the 1st International Conference on Energy, Environment and Climate Change (2011, August 26)

Renewable technologies are considered as clean sources of energy and optimal use of these resources minimize environmental impacts, produce minimum secondary wastes and are sustainable based on current ... [more ▼]

Renewable technologies are considered as clean sources of energy and optimal use of these resources minimize environmental impacts, produce minimum secondary wastes and are sustainable based on current and future economic and societal needs. Renewable energy technologies provide an excellent opportunity for mitigation of greenhouse gas emission and reducing global warming through substituting conventional energy sources. In the Sahel of West Africa, dramatically affected by desertification processes and rainfall shortages, wind energy is often viewed as a technology to mitigate deforestation although its development is extremely limited. The purpose of this study is to assess wind power potential in Niamey, Niger, a country where forest areas have declined by 34.5% over the 1990-2005 period. From 3-hourly meteorological data collected at the Niamey-Airport synoptic station over ten years (1998-2007), we evaluate the wind speed characteristics and the wind power potential at a height of 10 meters above ground level at diurnal, monthly, and yearly scales. We find very large differences in wind speed at the diurnal (2.40 – 5.11 m/s), monthly (2.61 – 4.11 m/s) and yearly (3.21 – 3.73 m/s) scales, with a global average wind speed of 3.42 m/s. We conclude that the wind powered energy is not economically feasible in Niamey due to its low wind potential. [less ▲]

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