L’étude des mares et des plaines alluviales du Niger supérieur et de ses affluents révèle la grande variété des modes de mise en valeur des ressources de ces milieux. Les pratiques hydro-agricoles recensées sont classées selon leur degré de maîtrise de l’eau, depuis les pratiques de submersion libre (Baro) ou partiellement contrôlée (Office Riz Ségou) jusqu’à l’irrigation gravitaire manuelle, motorisée (moto-pompage de la basse vallée du Sankarani) ou encore grâce à un barrage (périmètre irrigué de Baguinéda). La plupart des mares recensées fait par ailleurs l’objet de pêches collectives spectaculaires. Au-delà des apports nutritionnels issus de la pêche des poissons retenus prisonniers dans les points bas des plaines suite à la décrue du fleuve, ces rassemblements véhiculent des valeurs sociales, culturelles et symboliques fortes et emblématiques du Haut Niger.Les entretiens, les mesures hydrométriques ainsi que l’étude approfondie du cas de la plaine alluviale du Niandan à Baro, ont permis d’identifier les pratiques tributaires du régime fluvial. La réalisation future du barrage de Fomi sur le Niandan en Guinée pose la question du maintien de l’accessibilité des ressources – agricoles et de pêche – des plaines alluviales pour les populations riveraines. Les connaissances apportées sur la mise en valeur actuelle des plaines alluviales du Niger supérieur doivent par ailleurs permettre d’anticiper les impacts d’un tel ouvrage. L’étude des scenarii de gestion proposés jusque-là incite, à la lumière des retours d’expérience des grands barrages déjà existants en Afrique de l’Ouest, à notamment réexaminer l’intérêt de produire une crue artificielle. / The study of small lakes and alluvial floodplains of the Upper Niger River and its tributaries reveals the large variety of ways of developing the resources of these areas. The listed hydro-agricultural practices are classified according to their degree of water control, such as the practices of free flooding (Baro) or partially controlled flooding (Office Riz Ségou) as well as the ”gravity irrigation / surface irrigation”, which could be either manual or motorized (motorcycle-pumping of the low valley of Sankarani) or else thanks to a dam (irrigated perimeter of Baguinéda). Most of the listed small lakes are besides the object of spectacular collective peaches. Beyond the nutritional contributions stemming from the fishing of trapped fishes in the low points of the alluvial plains subsequent to the flood recession, these gatherings convey strong and symbolic social, cultural and symbolic values. Interviews and hydrometric measures as well as the depth study of the case of the alluvial floodplain of the Niandan River at Baro, allowed to identify the practices dependent on the river regime. The future realization of the dam of Fomi across the Niandan River in Guinea raises the question of the preservation of the accessibility of the resources - agricultural and fishing – of alluvial floodplains for local communities. The knowledge brought on the current development of the Upper Niger River besides have to allow to anticipate the impacts of such a work. In the light of the experience feedback of the already existing dams in West Africa, the study of the current river management leads to revise the interest of artificial flooding.

This dissertation titled ‘An appraisal of the law relating to oil pollution in the inland, territorial and maritime waters of Nigeria’ examines whether the law governing oil pollution in Nigeria is satisfactory in so far as determining issues of liability and compensation for oil pollution are concerned. The thesis examines a research hypothesis on the determination of the question whether the law adequately caters for victims of oil pollution occurring in the inland, territorial and maritime waters of Nigeria and if not, what are the observable defects and how can these defects be remedied. Not only has there been a considerable environmental degradation in Nigeria occasisoned by oil exploration and exploitation, particularly in the areas around the Niger Delta, but there has been serious socio-economic consequences pertinent to sustainable development of Nigeria as a nation. These impacts and the government’s attempts to tackle the problems have been the focus of this thesis. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

This thesis examines the social character of petroleum-related grassroots struggles in Nigeria’s oil-producing region. It does this against the background of the dominant scholarly narratives that portray the struggles as: a) a disguised pursuit of an ethnic/sectional agenda, b) a 'minority rights' project, and c) a minority province’s protest against 'selective' environmental 'victimisation' by the majority ethnic nationalities. While the dominant scholarly analyses of the struggles are based on the activities of the better known activist organisations operating in the oil region, this thesis focuses primarily on the everyday 'grammar' of discontent and lived worlds of ordinary people vis-à-vis upstream petroleum operations and petroleum resource utilisation. The aim has been to gain an understanding of the forces driving community struggles in the oil region and their wider societal significance. Examined alongside the narratives of ordinary people are the legal/institutional framework for upstream petroleum operations and the operational practices of the oil-producing companies. Using primary data obtained through ethnography, focus group discussions, in-depth interviews and visual sociology, as well as relevant secondary data, the researcher constructs a discourse matrix, showing how grassroots narratives in selected oilproducing communities intersect with contemporary civic discourses in the wider Nigerian context. The thesis highlights the theoretical and policy difficulties that arise when the social basis of petroleum-related grassroots struggles and ordinary people’s narratives are explained using an essentialist idiom. It reveals, above all, the conditions under which so-called 'locale-specific' struggles in a multi-ethnic, oil-rich African country can become a campaign for the emancipation of ordinary people in the wider society. This research extends the existing knowledge on citizen mobilisation, extractive capitalism, transnational corporate behaviour, and Nigeria’s contemporary development predicament. It sheds light on some of the processes through which ordinary people are forcing upon the state a change agenda that could drive the country along a more socially sensitive development and democratisation trajectory.

Les aménagements hydro-agricoles de la vallée du fleuve Niger se dégradent à cause des externalités négatives des activités agropastorales d’amont. A ces externalités on ne peut pas appliquer la taxe pigouvienne parce qu’elles sont diffuses, difficiles à évaluer en termes monétaires. Par contre, elles peuvent être maitrisées par des aménagements antiérosifs,lesquels ne sont pas spontanément adoptés par les agro-éleveurs. Le mécanisme de paiement pour des services environnementaux a été proposé pour inciter les pratiques antiérosives au niveau local entre agro-éleveurs pauvres situés en amont et riziculteurs dégageant des surplus rizicoles et situé en aval. Dans ce contexte, les paiements pour des services environnementaux sont-ils des outils incitatifs efficaces. Pour analyser cette problématique, tous les flux agronomiques et économiques ont été modélisés. Des scénarii ont été simulés afin d’évaluer la faisabilité et l’efficacité des mécanismes de paiements pour des services antiérosifs. Les simulations suggèrent que le mécanisme de paiement est intéressant. Les paiements permettent une meilleure redistribution des bénéfices et une réduction de la pauvreté. Tous les usagers sont gagnants. Les uns subventionnent les aménagements antiérosifs et les autres les adoptent. Ils créent des services antiérosifs qui améliorent la durabilité des ressources et une amélioration des revenus des exploitants. / The irrigation schemes of the River Niger valley are degrading because of the negative externalities of the agropastoral activities in upstream. To these externalities, we cannot apply the Pigouvian tax because they are diffuse and difficult to be assessed in money terms. Conversely, they can be mastered by erosion control, but that are not spontaneously adopted by agropastoralist. Thus, the mechanism of payment for environmental services has been proposed to study and analyze the possibility for production a sustained services of control erosion at the local level between poor agropastoralists and rice growers who realize production surpluses. Payments for environmental services are incentive tools, which are original and effective in producing sustained services. Flows of agricultural and economic interests have been modeled. Many scenarios have been simulating in order to assess the feasibility and effectiveness of payment mechanisms for erosion control services. The simulations show that the mechanism of payment was interesting between local users. The payment has made a better redistribution of profits and has alleviated poverty. All users are winners. Some users subsidize for an anti-erosion and other users have adopted them. They have created a sustainable anti-erosion service that has supported a more sustainable management of resources and has improved farm incomes.

Les sécheresses des années 1970 accentuées dans les années 1980 et les aménagements hydroagricoles ont eu pour conséquence une certaine dégradation des ressources naturelles du delta intérieur du fleuve Niger (DIN). Cette dégradation des ressources naturelles associées à la pression croissante de la population sur le milieu a conduit à une gestion conflictuelle de ces ressources. De plus, le système d’exploitation actuel des ressources et le fonctionnement hydrologique font du DIN un écosystème complexe à gérer. Dans ces travaux, nous adoptons une approche intégrée et pluridisciplinaire pour aborder la problématique de gestion des ressources du DIN. L’approche mobilise l’hydrologie, la sociologie, l’agronomie et l’économie. L’analyse des données hydrologiques a permis de mettre en évidence une différence significative entre les dates de passage des maximums des fleuves Niger et Bani qui alimentent le DIN. Cette différence impacte les calendriers des principaux systèmes de production contribuant ainsi à exacerber les conflits. Les stratégies de gestion élaborées avec les parties prenantes, allient des pratiques de sécurisation et de maîtrise de l’eau, d’intensification, de régénération des ressources, de renforcement des capacités et des incitations économiques. Par ailleurs, dans un contexte de variabilité climatique accrue, nous avons analysé les perceptions d’un échantillon de pêcheurs, d’éleveurs et de cultivateurs sur la prévision du climat et sur l’intérêt des prévisions climatiques et des crues. Il ressort que les besoins en information climatique des usagers d’une plaine inondable comme le DIN se rapportent surtout aux dates de début de saison, de passage des maximums de crue, de la date d’arrivée des crues et des hauteurs maximales de crue. L’intérêt économique simulé de l’information climatique pour un système agraire de riziculture inondée présente un gain moyen de 10%. Par contre le coût des éventuelles erreurs de prévision serait particulièrement élevé pour les producteurs avec un déficit moyen sur le revenu de 24%. / The droughts of the 1970s intensified in the 1980s and the development of irrigation schemes upstream of the Inner Niger Delta in Mali (IND) have resulted in the degradation of natural resources. This degradation of natural resources associated with the increasing population pressure on the environment has led to a more conflictive management of these resources. In addition, the current operating system of resources and the hydrological functioning of the IND make the management of the ecosystem more complex.In this work, we adopt an integrated and multidisciplinary approach to address the IND resource management issues. The approach mobilizes hydrology, sociology, agronomy and economy.The analysis of hydrological data has highlighted a significant difference between the maximum passing dates of the two rivers that supply the IND. This difference impacts the schedules of the main production systems thus contributing to exacerbate conflict. The management strategies developed with stakeholders combine the practices of security and water control, intensification, resource regeneration, capacity building and economic incentives. Moreover, in a context of increased climate variability, we analyzed the perceptions of a sample of fishermen, herders and farmers on climate prediction and their interest of climate and flood forecasts.. It appears that the need for climate information of floodplain users as IND relate mainly to the onset date of rainy season, flood maximum passaging date, the arrival of floods and flood peak heights.The simulated economic value of climate information for an agrarian system of flooded rice obtains an average gain of 10%. As against the cost of possible prediction errors is particularly high for producers with an average deficit on income of 24%.

Dams and reservoirs with multiple purposes require effective management to fully realize their purposes and maximize efficiency. For instance, a reservoir intended mainly for the purposes of flood control and hydropower generation may result in a system with primary objectives that conflict with each other. This is because higher hydraulic heads are required to achieve the hydropower generation objective while relatively lower reservoir levels are required to fulfill flood control objectives. Protracted imbalances between these two could increase the susceptibility of the system to risks of water shortage or flood, depending on inflow volumes and operational policy effectiveness. The magnitudes of these risks can become even more pronounced when upstream use of the river is unregulated and uncoordinated so that upstream consumptions and releases are arbitrary. As a result, safe operational practices and risk management alternatives must be structured after an improved understanding of historical and anticipated inflows, actual and speculative upstream uses, and the overall hydrology of catchments upstream of the reservoir. One of such systems with an almost yearly occurrence of floods and shortages due to both natural and anthropogenic factors is the dual reservoir system of Kainji and Jebba in Nigeria. To analyze and manage these risks, a methodology that combines a stochastic and deterministic approach was employed. Using methods outlined by Box and Jenkins (1976), autoregressive integrated moving average (ARIMA) models were developed for forecasting Niger river inflows at Kainji reservoir based on twenty-seven-year-long historical inflow data (1970-1996). These were then validated using seven-year inflow records (1997-2003). The model with the best correlation was a seasonal multiplicative ARIMA (2,1,1)x(2,1,2)12 model. Supplementary iv validation of this model was done with discharge rating curves developed for the inlet of the reservoir using in situ inflows and satellite altimetry data. By comparing net inflow volumes with storage deficit, flood and shortage risk factors at the reservoir were determined based on (a) actual inflows, (b) forecasted inflows (up to 2015), and (c) simulated scenarios depicting undefined competitive upstream consumption. Calculated highrisk years matched actual flood years again suggesting the reliability of the model. Monte Carlo simulations were then used to prescribe safe outflows and storage allocations in order to reduce futuristic risk factors. The theoretical safety levels achieved indicated risk factors below threshold values and showed that this methodology is a powerful tool for estimating and managing flood and shortage risks in reservoirs with undefined competitive upstream consumption

Depuis le développement des mesures satellites de nombreuses missions spatiales sont dédiées au suivi de l'atmosphère et de la surface terrestre. Ces travaux de thèse s'inscrivent dans le cadre de la mission Megha-Tropiques dédiée au cycle de l'eau et de l'énergie en zone tropicale. L'objectif est d'évaluer le potentiel des estimations de précipitation par satellite pour des applications hydrologiques en zone tropicale. Les Tropiques réunissent les plus grands fleuves du globe, mais ne bénéficient pas de réseaux d'observation in-situ denses et continus permettant une gestion intégrée efficace de la ressource et des systèmes d'alertes. Les estimations des précipitations issues des systèmes d'observation satellite offrent une alternative pour ces bassins peu ou pas instrumentés et souvent exposés aux extrêmes climatiques. C'est le cas du fleuve Niger, qui a subi une grande variabilité climatique depuis les années 1950, mais aussi d'importants changements environnementaux et hydrologiques. Depuis les années 2000, le Niger moyen connaît une recrudescence des inondations pendant la période de crue Rouge (engendrée par ses affluents sahéliens pendant la mousson). A Niamey, des niveaux record de hauteur d'eau et de période d'inondation ont été enregistrés en 2003, 2010, 2012 et 2013, engendrant de nombreuses pertes humaines et matérielles. Ces travaux analysent l'influence du forçage pluviométrique sur les inondations liées à la crue Rouge à Niamey. Une gamme de produits pluviométriques (in situ et satellite) et la modélisation hydrologique (ISBA-TRIP) sont combinés pour étudier : (i) l'apport des produits satellite pour diagnostiquer la crue Rouge récente, (ii) l'impact des caractéristiques des produits et de leurs incertitudes sur les simulations et enfin (iii) l'évaluation du rôle des précipitations, face aux changements de conditions de surface, dans l'évolution de la crue Rouge à Niamey depuis les années 1950. L'étude a mis en évidence l'impact des caractéristiques des estimations des précipitations (cumul, intensité et distribution spatio-temporelle) sur la modélisation hydrologique et le potentiel des produits satellites pour le suivi des inondations. Les caractéristiques des précipitations se propageant dans la modélisation, la détection des inondations est plus efficace avec une approche relative à chaque produit plutôt qu'avec un seuil absolu. Ainsi des produits présentant des biais peuvent être envisagés pour la simulation hydrologique et la détection des inondations. Le nouveau produit TAPEER de la mission MT présente un fort potentiel hydrologique, en 2012 et pour la zone d'étude. D'autre part, l'étude de la propagation de l'erreur associée à ces précipitations a mis en évidence, la nécessité de déterminer la structure du champ d'erreur pour l'utilisation d'une telle information en hydrologie. Enfin la modélisation a été utilisée comme levier pour décomposer les sensibilités de la crue Rouge aux variations des précipitations et des conditions de surface. Pour simuler les changements hydrologiques entre les périodes 1953-1982 et 1983-2012, les changements d'occupation du sol et d'aire de drainage doivent être pris en compte. Puis les variations des précipitations peuvent expliquer les changements majeurs décennaux et annuels entre les années 1983 et 2012. / Since the development of satellite based remote sensing in the 1970s, many missions have been dedicated to monitoring the terrestrial atmosphere and surfaces. Some of these satellites are dedicated to the Tropics with specific orbits. Megha-Tropiques (MT) is devoted to the water and energy cycle in the tropical atmosphere and provides an enhanced sampling for rainfall estimation in the tropical region. This PhD work was initiated within MT hydro-meteorological activities, with the objective of assessing the hydrological potential of satellite rainfall products in the Tropics. The world most important rivers lay in tropical areas where the in situ observation networks are deficient. Alternative information is therefore needed for water resource management and alert systems. The present work focuses on the Niger River a basin which has undergone drastic climatic variations leading to disasters such as droughts and floods. Since 1950, the Niger has been through 3 main climatic periods: a wet period (1950-1960), a long and intense drought period (1970-1980) and since 1990 a partial recovery of the rainfall. These climatic variations and the anthropic pressure, have modified the hydrological behaviour of the basin. Since 2000, the middle Niger River has been hit by an increase of floods hazards during the so-called Red flood period. In Niamey city, the highest river levels and the longest flooded period were recorded in 2003, 2010, 2012 and 2013, leading to heavy casualties and property damage. This study combines hydrological modelling and a variety of rainfall estimation products (satellite and in-situ) to meet several objectives: (i) the simulation of the Niamey Red flood and the detection of floods (during the recent period 2000-2013) (ii) the study of the propagation of satellite rainfall errors in hydrological modelling (iii) the evaluation of the role of rainfall variability, and surface conditions, in the changes of the Red flood in Niamey since the 50s. The global model ISBA-TRIP, is run with a resolution of 0.5° and 3h, and several rainfall products were used as forcing. Products derived from gauges (KRIG, CPC), pure satellite products (TAPEER, 3B42RT, CMORPH, PERSIANN) and mixed satellite products adjusted by rain gauges (3B42v7, RFE2, PERSIANN-CDR). This work confirms the hydrological potential of satellite rainfall products and proposes an original approach to overcome their biases. It highlights the need for documenting the errors associated with the rainfall products and the error structure. Finally, the hydrological modelling results since the 1950s have given a new understanding of the relative role of rainfall and surface conditions in the drastic increase of flood risk in Niamey.

Conventionally environmental assessments (EAs) have been carried out to enhance the understanding of the environment and for the purpose of developing appropriate environmental management and protection strategies. There are, however, limitations to the application of traditional EA approaches, particularly in rural communities in the developing world, where livelihood is dependent on common pool resources (CPRs), and baseline data are inadequate or unavailable. Eco-livelihood assessment (EcLA) is an adaptive approach that integrates a people focused sustainable livelihood approach with ecological assessment, as well as exploring traditional eco-livelihood knowledge (TELK). EcLA is identified as a promising EA tool that could help environmental professionals in planning for equitable development. This approach has been used in the Kolo and Otuoke Creeks, Niger Delta, Nigeria to investigate the ecological impact of dredging that may impact on livelihoods in such a rural setting. Ecological and social surveys have been carried out in four communities in the Study Area; two Test communities and two Reference communities (two communities from each study creek). The information collected from the social survey includes TELK, and has been used to build up a baseline scenario of the Study Area. Abundance and diversity of fish are good indicators of the eco-livelihood impacts of inland river dredging. The research shows that livelihood characteristics, river use profile, fish species diversity and abundance are very similar among all four sample communities. In addition, all sample communities have been associated with similar natural and human induced environmental consequences except that the Test communities have had river sections dredged for the purpose of land reclamation representing the baseline scenario. The analysis of the results of the ecological survey shows a difference in fish catch per unit effort, catch per unit hour, and species diversity between the Test and Reference communities, this have been attributed to the impacts of inland river dredging. The study shows that TELK has a place in environmental assessment, and that eco-livelihood assessment is one promising environmental assessment approach that could be used in areas where livelihood is strongly dependent on common pool resources.

Univ., Diss.--Göttingen, 2007.