Quantification of groundwater recharge is a crucial prerequisite for sustainable groundwater resource management, particularly in semi-arid areas where there are large demands for groundwater supplies. This research presents an alternative approach for recharge estimation based on the soil water balance technique. The purpose is to develop a model which provides a suitable balance between physical credibility and data which realistically can be gathered. A spreadsheet model was written based on the conceptual representation of the principal physical processes which actually affect recharge in a semi-arid area. Alternative procedures were included in order to represent: (a) the estimation of runoff, (b) the inclusion of the period with predominant bare soil evaporation and (c) the accounting for evapotranspiration following rainfall on dry soil. The model was tested using real data from a semi-arid region (Northeast Nigeria) making use of selected periods of days and years in order to illustrate the principal model characteristics. The results were presented in the form of diagrams and graphs helping to visualise the interactions between the physical components and the effect of the additional procedures on recharge estimation. The credibility of the model was investigated using an alternative concept of 'analysis of plausibility'. This concept makes use of as wide as possible a range of quantitative and qualitative information from the hydrological system in order to verify the robustness of the model when extensive datasets required by conventional validation techniques are not available. The results suggested that the modelled recharge is physically sound and it is in line with the overall determination of recharge in semi-arid areas by a range of methods. The soil water balance model was utilised to explore important aspects of recharge in semi-arid regions showing the effect of the field variability on the model's output. The preliminary results show that the developed concept reasonably represents the inherent field variability, thus corroborating the strength of the approach for recharge estimation in semi-arid regions.

La gestion d'une ressource en eau souterraine utilisée pour l'irrigation est un phénomène dépendant de plusieurs facteurs et concernant différents acteurs (utilisateurs et gestionnaire). En cas d'aléa climatique comme la sécheresse, gérer une ressource devient un problème plus complexe. Il est justement important de mieux comprendre et d'anticiper les sécheresses car ils peuvent avoir des impacts significatifs sur l'activité économique agricole et sur les niveaux de la ressource. Pour cela, le type d'information dont disposent les utilisateurs et/ou les gestionnaire est essentiel. Dans les chapitres 2 et 3, nous analysons l'impact d'une sécheresse "hydrologique" sur la gestion optimale de la ressource, avant et après son arrivée. Dans le chapitre 2, nous montrons comment le gestionnaire de la ressource peut s'adapter le mieux possible à cette sécheresse selon l'information dont il dispose. Dans le chapitre 3, nous montrons que la prise en compte des interactions stratégiques et dynamiques entre les utilisateurs de la ressource entraîne une exploitation moins efficace de la ressource. Nous appliquons les modèles des chapitres 2 et 3 à l'aquifère La Mancha Occidentale au Sud de l'Espagne. Dans le chapitre 4, nous analysons l'impact d'une sécheresse "agronomique" sur la gestion optimale d'une exploitation agricole située dans la zone de la Beauce centrale, en France. Nous prenons en compte des informations de caractère hydrologique, agronomique et économique. En particulier, nous étudions l'impact d'une année sèche sur la valeur ajoutée de l'exploitation et sur la ressource en eau utilisée. De plus, nous nous intéressons au comportement stratégique que les agriculteurs peuvent avoir en année sèche, que ce soit sans ou avec restrictions des usages de l'eau. Nous montrons qu'une politique de régulation est nécessaire pour éviter la surexploitation de la nappe en année sèche. / The management of a groundwater resource used for irrigation is a phenomenon that depends on several factors and concerning various actors (users and manager). Moreover, the resource can be subject to droughts. In this case, the management of the resource becomes a more complex problem. Adaptation to droughts is important because they can have significant impacts on agriculturalactivity and on the water table of the resource. This adaptation hinges crucially on the information available to the manager and the resource users. In chapters 2 and 3, we analyze the impact of an hydrological drought on the optimal management of the resource, before and after its arrival. In particular, in chapter 2, we show how the manager can adapt as good as possible to this drought according to the nature of information he has. In chapter 3, we are show that taking into account strategic and dynamic interactions between the users of the ressource leads to less efficient resource use. We apply models of chapters 2 and 3 to the aquifer Western La Mancha, in Spain. In chapter 4, we study the impact of an agronomic drought on the optimal management of a farm in the area of Central Beauce, in France. We take into account hydrological, agronomic and economic informations. In particular, we analyze the impact of a dry period on the annual benefits of the farm and on the groundwater resource level. Furthermore, we study optimal strategic behavior of farmers in a dry year, whether they are subject to water restrictions or not. We show that a regulation policy is necessary to avoid the overexploitation of the ressource in a dry year.

La ville de Tamanrasset comme une ville récente du Sahara central, a été confrontée au long de son histoire à un problème d’approvisionnement en eau potable. Cette situation qui endure la population de la ville a dû d’une croissance démographique rapide (sédentarisation, immigration), une urbanisation anarchique et à des ressources en eau très limites. Avec, la persistance de la pénurie, les difficultés d’accès à l’eau potable, et une gestion étatique inefficace, les habitants ont toujours fait recours aux services des revendeurs d’eau par les camions-citernes, et ont développé des dispositifs de stockage plus au moins sophistiqués pour assurer une consommation régulière à l’intérieur de l’habitation, tout en étant indépendant du programme de rotation du distribution élaboré par l’A.D.E. Pour résoudre le problème de la pénurie d’eau ; il a fallu attendre l’intervention de l’état algérien par la réalisation d’un grand projet d’adduction en transférant des eaux fossiles (albienne) du bas Sahara vers la ville de Tamanrasset (700 km). Il est à signaler que ce passage d’une gestion de pénurie vers celle d’abondance reste un défi qui nécessite plus de moyens et d’attention. D’une manière plus précise, le travail que nous avons mené concerne les interactions entre le rationnement, imposé par les services de l’eau de la ville en conséquence du manque d’eau et d’une politique de gestion inadéquate avec les spécificités locales, et les solutions envisagées par les usagers et l’état. / The city of Tamanrasset as a new city in the central Sahara was faced throughout its history to a water supply problem. This situation endures the population of the city had a rapid population growth (settlement, immigration), uncontrolled urbanization and limits water resources. With the persistence of the shortage, lack of access to safe drinking water, and inefficient state management, people have always used the services of water reseller’s tankers, and developed storage devices more or less sophisticated to ensure regular consumption in within the housing, while being independent of rotation program distribution developed by the ADE. To solve the problem of shortage of water, it took the intervention of the Algerian state by carrying out a large supply project by transferring fossil water (Albian) of the down Sahara to the city of Tamanrasset (700 km). It should be noted that the passage of a management shortage to abundance that remains a challenge requiring more resources and attention. More specifically speaking, the work we've done for the interactions between the rationing imposed by the water services in the city as a result of lack of water and inadequate management policy, with specific local and the solutions envisaged by users and the state.

Orientador: Chang Hung Kiang / Banca: Monica Ferreira do Amaral Porto / Banca: Cláudio Antonio de Mauro / Resumo: Sistemas de informações geográficas permitem a visualização, manipulação e análise de dados espaciais, que podem incorporar diversos modelos hidrológicos. Esta dissertação apresenta a aplicação de Sistemas de Informações Geográficas em Gestão de Recursos Hídricos Subterrâneos, desenvolvendo funcionalidades de análises que possibilitam consistir as coordenadas de implantação de um poço contra temas da base cartográfica da aplicação; consistir a profundidade projetada para a poço contra as espessuras das unidades hidroestratigráficas; analisar dentro de um raio de proximidade do poço projetado a existência de outros poços e as vazões outorgadas; calcular o raio de interferência do poço; calcular a vazão explorável em função do tempo de bombeamento; analisar espacialmente a sobreposição dos raios de interferências entre poços e cadastrar as análises efetuadas. Foi utilizado a software ArcGIS como plataforma de SIG. 0 banco de dados foi implementado em formato Personal Geodatabase. A documentação de desenvolvimento de software utilizada seguiu os padrões estabelecidos pelo RUP­Rational Unified Process. 0 sistema foi aplicado e testado na Unidade de Gerenciamento de Recursos Hídricos do Pontal do Paranapanema (UGHRI-22), no estado de São Paulo, tendo sido incorporadas as unidades hidroestratigráficas dos sistemas aqüíferos Bauru e Guarani. / Abstract: The geographic information systems (GIS) are capable of visualization, manipulation and analysis of georeferenced data, providing interface capability with different hydrological models. This dissertation focus on the application of geographic information systems in the context of groundwater management, proViding functionalities of analysis which allow to link and check the coordinates and the depths of a projected water well to the various thematic database. It analyzes within a range of the radius of influence of the projected well the number and total discharge of the existing wells. Furthermore, it calculates the interference radius of the well and the maximum rate of production as function of pumping time. It analyzes the overlapping of wells and records the results of the analysis. The dissertation uses the ArcGIS software system as working platform for GIS. The database was implemented in the Personal Geodatabase format. The documentation of software development followed the protocols established by RUP - Rational Unified Process. The system was applied and tested in the Water Resource Management Unit of Pontal do Paranapanema (UGHRI-22), in the state of Sao Paulo, incorporating hydrostratigraphical units of the Bauru and Guarani aquifer systems. / Mestre

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Made available in DSpace on 2014-06-11T19:26:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-12-04Bitstream added on 2014-06-13T20:54:22Z : No. of bitstreams: 1 barbosa_sa_me_rcla_prot.pdf: 4243732 bytes, checksum: d8d48af38f82a7055a18d2daabc32e88 (MD5) / Sistemas de informações geográficas permitem a visualização, manipulação e análise de dados espaciais, que podem incorporar diversos modelos hidrológicos. Esta dissertação apresenta a aplicação de Sistemas de Informações Geográficas em Gestão de Recursos Hídricos Subterrâneos, desenvolvendo funcionalidades de análises que possibilitam consistir as coordenadas de implantação de um poço contra temas da base cartográfica da aplicação; consistir a profundidade projetada para a poço contra as espessuras das unidades hidroestratigráficas; analisar dentro de um raio de proximidade do poço projetado a existência de outros poços e as vazões outorgadas; calcular o raio de interferência do poço; calcular a vazão explorável em função do tempo de bombeamento; analisar espacialmente a sobreposição dos raios de interferências entre poços e cadastrar as análises efetuadas. Foi utilizado a software ArcGIS como plataforma de SIG. 0 banco de dados foi implementado em formato Personal Geodatabase. A documentação de desenvolvimento de software utilizada seguiu os padrões estabelecidos pelo RUP­Rational Unified Process. 0 sistema foi aplicado e testado na Unidade de Gerenciamento de Recursos Hídricos do Pontal do Paranapanema (UGHRI-22), no estado de São Paulo, tendo sido incorporadas as unidades hidroestratigráficas dos sistemas aqüíferos Bauru e Guarani. / The geographic information systems (GIS) are capable of visualization, manipulation and analysis of georeferenced data, providing interface capability with different hydrological models. This dissertation focus on the application of geographic information systems in the context of groundwater management, proViding functionalities of analysis which allow to link and check the coordinates and the depths of a projected water well to the various thematic database. It analyzes within a range of the radius of influence of the projected well the number and total discharge of the existing wells. Furthermore, it calculates the interference radius of the well and the maximum rate of production as function of pumping time. It analyzes the overlapping of wells and records the results of the analysis. The dissertation uses the ArcGIS software system as working platform for GIS. The database was implemented in the Personal Geodatabase format. The documentation of software development followed the protocols established by RUP - Rational Unified Process. The system was applied and tested in the Water Resource Management Unit of Pontal do Paranapanema (UGHRI-22), in the state of Sao Paulo, incorporating hydrostratigraphical units of the Bauru and Guarani aquifer systems.