Thesis (M.S.)--University of Wisconsin--Stevens Point, 2007. / Includes bibliographical references (p. 47-49).

Thesis (M.S.) -- Worcester Polytechnic Institute. / Keywords: water quality; fecal coliforms; land use. Includes bibliographical references (p. 80-83).

Thesis (M.S.) in Marine Biology--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 100-109).

Thesis (M.Sc. Earth and Ocean Sciences)--University of Waikato, 2007. / Includes bibliographical references (leaves 139-148) Also available via the World Wide Web.

Thesis (M.S.)--University of Nevada, Reno, 2005. / "December, 2005." Includes bibliographical references. Online version available on the World Wide Web.

Thesis (M.S.)--University of Wisconsin--Stevens Point, 2007. / Includes bibliographical references (leaves 62-66).

Thesis (M. Sc. (Zoology and Entomology))--Rhodes University, 2006.

Thesis (M. Sc.)--University of Hong Kong, 1999. / Includes bibliographical references (leaves 65-68).

Depuis les années 70, le niveau de l'eau dans les aquifères du sous-sol de la ville de Ouagadougou a subi des fluctuations considérables. Dans cette thèse, 1) nous avons mis en place un réseau piézométrique local autour du piézomètre CIEH à l'Université de Ouagadougou, 2) observé les fluctuations du niveau d'eau dans ce réseau piézométrique au cours d'une année hydrologique, 3) modélisé, en utilisant un modèle boîte 1D simple, le niveau de l'eau dans le réseau piézométrique, 4) évalué la capacité de mesure gravimétrique pour mesurer les fluctuations du niveau d'eau lors d'une modélisation de pompage de l'aquifère pendant 7 jours, 5) mesuré la variabilité des principaux éléments chimiques dans notre réseau piézométrique entre la fin de la saison sèche et la fin de la saison des pluies.Le modèle boîte 1D choisi est dérivé du modèle de GARDENIA du BRGM. Il comporte trois réservoirs, le premier décrit les premiers centimètres du sol où l'évapotranspiration intervient, le second joue le rôle d'un tampon d'entrée de l'eau dans le troisième réservoir aquifère. La modélisation de l'ensemble du réseau piézométrique au cours d'une année hydrologique permet d'évaluer un bilan de précipitations. Les résultats obtenus correspondent à l'occupation des terres de chaque puits, ancien faubourg, zone naturelle et zone récemment urbanisée. Une tentative de modéliser l'ensemble des niveaux piézométriques, depuis 1978 au CIEH a échoué et cela est interprété comme un effet de l'utilisation des terres, combinée à la nécessité d'utiliser des coefficients différents pour une année sèche et une année très humide. Comme les paramètres hydrologiques varient en fonction du climat et de l'utilisation des terres près du CIEH, la méthode habituelle en utilisant les premières années de l'enregistrement pour l'étalonnage du modèle et les années suivantes pour l'évaluation de la validité du modèle ne peut pas être appliquée.Les 7 jours de test de pompage théorique de l'aquifère ont été modélisés en utilisant MODFOW/PMWIN et une grille d'espacement variable avec un maillage de 0,2 m près du puits augmentant progressivement jusqu'à 2 km près de la frontière de la boîte de modélisation a été conçue. Ce modèle est calibré sur des solutions analytiques et numériques publiées dans la littérature et est combiné avec un modèle gravimétrique fonctionnant sur la même grille. Les résultats de gravité ont été à nouveau validés sur la littérature. Trois cas tests ont été étudiés 1) pompage dans la couche de la latérite, 2) pompage dans le milieu fissuré horizontalement sous les latérites, 3) pompage dans une fracture où le milieu fissuré est profond. Les propriétés hydrauliques de la latérite étaient censées être connues, alors que la conductivité hydraulique était inconnue. Pour le cas de la fracture, il est démontré que, aujourd'hui, les données de gravité seules ne sont pas en mesure de limiter la conductivité inconnue de la couche fissurée. Cependant, le nivellement des données sur l'affaissement des latérites pendant le pompage, combiné avec les données gravimétriques, permet de récupérer ce paramètre avec une incertitude raisonnable.Nos analyses chimiques étaient de mauvaise qualité. Cependant, en se concentrant sur les sulfures et les nitrates, qui ne présentent pas d'erreurs notables, il se confirme 1) qu'il y a encore dans la ville de Ouagadougou des eaux souterraines de qualité potable (à confirmer par des analyses plus approfondies), 2) que les niveaux de sulfure et de nitrate élevés peuvent être atteints au cours de la saison des pluies (c'est probablement lié à la montée des eaux près de la surface). Il est suggéré en conclusion que des résultats intéressants peuvent être obtenus à Ouagadougou par la surveillance à long terme de quelques piézomètres à la fois pour le niveau et pour la qualité de l'eau. / During the 70s the water level in basement aquifers of the city of Ouagadougou underwent large level fluctuations. In this PhD thesis 1) we set up a local piezometric network around the so called CIEH piezometer in the University of Ouagadougou, 2) observe the fluctuations of the water level in this piezometric network during one hydrologic year, 3) model, using a 1D simplified box model the water level in the piezometric network, 4) assess the capability of gravimetric measurement to measure water level fluctuations during a 7 days aquifer test, 5) measure the variability of major chemical species in our piezometric network between the end of the dry season and the end of the rain season.The 1D box model is derived from the GARDENIA model of BRGM. It involves three compartments, the first ones describes the first few centimeters of soil, from which evapotranpiration is supposed to take place; the second one buffers the input of water to the third one which the aquifer. Modeling the whole piezometric network during one hydrological year allows to compute a rainfall budget. The results correspond the land occupation of each well, old suburb; natural area, and recently urbanized area. An attempt to model the whole piezometric record, lasting since 1978 at CIEH was unsuccessful and this is interpreted as an effect of land use change, combined to the need of different coefficients for a dry year and a very wet year. As the hydrological parameters are drifting as function of climate and of land use changes near the CIEH well, the usual method using the first years of the record for calibration of the model and the following years for its assessment cannot therefore be applied.The theoretical 7 days aquifer test experiment was modeled using MODFOW/PMWIN and a variable spacing grid with a mesh size of 0.2 m near the pumped borehole increasing progressively to nearly 2 km at the border of the modeling box. This model is calibrated along analytic and numerical solutions published in the literature and is combined with a gravimetric model operating on the same grid. The gravity results were once again validated against published literature. Three cases of aquifer test were considered : 1) pumping in the laterite layer, 2) pumping in the horizontally fissure medium below the laterites, 3) pumping in a fracture where the fissured medium is deepening. The hydraulic properties of laterite were supposed to be known, while the hydraulic conductivity of the fissured medium was unknown. For the case of the fracture, it is shown that with present days accuracy gravity data are not able alone to constrain the unknown conductivity of the fissured layer. However leveling data on the subsidence of laterites during pumping when combined with gravity data allow recovering this parameter with a reasonable accuracy.Our chemical analyses were of poor quality. However focusing on sulfides and nitrates, which should not be strongly affected with errors confirm 1) that there are still inside Ouagadougou groundwater of potable quality (to be confirmed with more extensive analyses), 2)high sulfide and nitrate levels can be reached during the rain season (this is probably linked the water level rising near the surface).It is suggested in conclusion that valuable results could be obtained in Ouagadougou by long term monitoring of a few piezometers both for water level and for water quality.

Made available in DSpace on 2016-08-10T10:44:19Z (GMT). No. of bitstreams: 1 CLEIDE MOCO LIMA.pdf: 1281674 bytes, checksum: a18776358c4f0b8fd600ceb0770b47f2 (MD5) Previous issue date: 2009-06-25 / Stream Barreiro in Goiânia-GO is a Meia Ponte s tributary. It has approximately 8 km long and has 10 sources distributed in six neighborhoods. Currently, it has been shown that these sources are suffering more negative interventions to ecosystems due the growth of city and raising the level of pollution. In this research were studied the sources, quality of water and environmental impacts. Six sources are completely dry. One is located at Oscar Niemeyer Culture Center. Two are located near GO- 020. The main source is located in private property in Jardim da Luz. Three points were designed to collect. Water quality was analyzed by Standart Methods. Point 1 was outburst in the water, the middle section 2 and section 3 of the dam at the outlet of water to the bed of the stream. It was observed that water in point 1 is great quality, according to the parameters analyzed. However, the other two points of collection showed changes, mainly in conductivity, turbidity, alkalinity, hardness, OD, DBO e coliforms. These points the water is dammed and a large variety of aquatic animals. On site there is no riparian vegetation and the environment is completely anthropogenic disturbance. / O córrego Barreiro em Goiânia-GO é um afluente do rio Meia Ponte, apresenta aproximadamente 8 km de extensão e possui 10 nascentes distribuídas em seis bairros residenciais. Atualmente, tem sido evidenciado que estas nascentes vêm sofrendo várias intervenções negativas para os ecossistemas, devido ao crescimento da cidade e elevação do nível da poluição. Os objetivos desta pesquisa foram avaliar as nascentes do córrego Barreiro, determinar a qualidade da água da nascente localizada no bairro Jardim da Luz e a água da mesma a qual é usada para criação de peixes, em termos físico-químicos e microbiológicos. Os métodos de análises foram segundo Standard Methods. Foram definidos três pontos de coleta, sendo o ponto 1 no afloramento da água, o ponto 2 no meio da represa e o ponto 3 na saída da água para o leito do córrego. A qualidade da água foi avaliada por medidas de temperatura, condutividade elétrica, cor, pH, turbidez, alcalinidade total, dureza, OD, DBO, STD, STS, coliformes totais e termotolerantes. As coletas foram realizadas no período seco. Observou-se que seis nascentes do córrego encontram-se completamente secas. Uma está localizada no centro Cultural Oscar Niemeyer e duas se encontram nas proximidades da rodovia GO- 020. A nascente Jardim da Luz é a de maior vazão e se encontra dentro de uma propriedade particular, a qual foi objeto de estudo. De modo geral no ponto 1, a água se encontra em ótima qualidade, segundo os parâmetros analisados, ou seja e límpida, inodora e com ausência de coliformes fecais. No entanto, nos outros dois pontos de coleta, onde existe a criação de peixes, a água apresentou alterações nos parâmetros físico-químicos, na condutividade, turbidez, alcalinidade, dureza, OD, DBO e coliformes. Nestes pontos a água está represada e existe uma grande variedade de animais aquáticos. No local não existe mata ciliar e a nascente está completamente antropizada. Todas as nascentes do córrego não estão protegidas e não houve respeito à Legislação