O objetivo principal desta pesquisa foi desenvolver um modelo de simulação dinâmica para a valoração ecológica de serviços ecossistêmicos hídricos, baseado em princípios de Dinâmica de Sistemas com o auxílio do software STELLA. A hipótese básica adotada foi que: a valoração ecológica dos serviços ecossistêmicos deve contar com uma ferramenta integradora dos elementos envolvidos na modelagem ecológica como requisito básico para compreensão da dinâmica ecossistêmica que gera fluxos de serviços ecossistêmicos hídricos (SEH). Os SEH são os benefícios gerados a partir das complexas interações, entre os componentes do ciclo hidrológico e que tem a ver com a preservação tanto em quantidade como em qualidade da oferta de água. O modelo foi desenvolvido, através de uma análise sistêmica dos processos ecossistêmicos compreendidos dentro do ciclo hidrológico, foram determinadas as principais variáveis e suas respectivas inter-relações, de acordo com a estrutura desse ciclo. Essa estrutura foi representada no diagrama causal, que serviu de base à elaboração do diagrama de estoque e fluxo, por meio do qual se estabeleceu o modelo matemático que permitiu efetuar a simulação numérica. A escala temporal de aplicação do modelo é diária e foram efetuadas 365 simulações, o que permitiu estimar fluxos anuais de SEH. O modelo foi parametrizado na sub-bacia das Posses, Município de Extrema, Minas Gerais; aqui esta sendo implementado o primeiro projeto piloto, baseado na relação floresta-água, de pagamentos por SEH do Brasil. Foram examinados 36 cenários, com o objetivo de avaliar o impacto que têm variáveis como: textura de solo, altura da vegetação, índice de área foliar e profundidade do lençol freático na geração dos fluxos de SEH em água na superfície, infiltrada e armazenada; porém foi avaliado como estes incidem de forma quantitativa na manutenção da oferta de água disponível. O modelo desenvolvido permitiu aumentar a compreensão dos fluxos de SEH, o que representa uma ferramenta de elevado potencial de aplicação nas fases de definição de âmbito, de avaliação de alternativas e monitoramento de esquemas de pagamentos por SEH no Brasil. / The main objective of this research was to develop a dynamic simulation model to valuate ecological hydrological ecosystem services. The principles of System Dynamics were applied using the software STELLA. A basic hypothesis was adopted: ecological valuation of ecosystem services must use a tool to integer all the elements involved in ecological modeling, as a basic requirement to understand the ecosystem dynamic that generates water fluxes as hydrological ecosystems services (HES). HES are the benefits generated from complex interactions that occur within the hydrologic cycle; those interactions deals with the preservation of available water, in quantity and quality. The model was developed after a systemic analysis of the ecosystem processes involved in the hydrologic cycle; pointing out the main variables and the interrelations that constitute it. Then, the structure of those relations was represented in a causal diagram; becoming the base to built up the stocks and flows diagram. This later diagram established the mathematical model that allowed the numerical simulation. The time step of the model is one day during 365 days, estimating annual water HES. The model was parameterized at Poses sub-watershed, Extrema County, Minas Gerais. In Extrema was established the first payment for HES project in Brazil, based on the relationship between forest land and water availability. Thirty six scenarios were studied considering surface, infiltrated and stored water services fluxes; affecting the availability of water. The objective of those scenarios was to evaluate the impact that variables such as: soil texture, vegetation height, leaf area index and groundwater depth have on water flux generation. The model developed enables to increase the understanding of HES fluxes, becoming a tool with a broad spectrum of applications during the stages of assessing and scoping alternatives for payment of environmental services and to monitor HES programs in Brazil.

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No. of bitstreams: 1 Dissertação - Hietor Thury Barreiros Barbosa.pdf: 1175425 bytes, checksum: 8796f8dda2460d2eda8171dbac3181a4 (MD5) Previous issue date: 2013-04-11 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Marked by a well defined alternation between the terrestrial and aquatic stages, the Amazon floodplain has a low climatic seasonality, with daily oscillations on temperature higher than annual and less pronounced variation of the photoperiod throughout the year. These environments are also characterized by the standard uni-modal and predictable flood with large seasonal variation in water level. For the fish fauna of the floodplain, the direct effects of changes in water level include severe changes in community composition and density of the population, conditioned by changes in limnological characteristics and the availability of food. Such seasonal variations in terms of feeding and reproductive responses may be expressed by the condition factor, quantitative indicator of the wellfare in front of the fish conditions of their environment. This study aimed to provide information on the seasonal variation of fish species condition factor in the Jaitêua and São Lourenço lakes that composes the Lago Grande System in the city of Manacapuru, Amazonas State. Data collect were made monthly for the period from July 2006 to July 2007. Once the condition factor were calculated, the comparisons between periods were performed by ANOVA. The comparisons between sexes and between juveniles and adults were made by t test. PCA was used to identify groups of species whose pattern of variation of the condition factor is similar. After critical data analysis, there were selected 13 species to study. The seasonal variation of the condition factor was significant for Acestrorhynchus falcirostris, Triportheus albus, Triportheus auritus, Potamorhina altamazonica, Potamorhina latior, Pygocentrus nattereri, Serrassalmus altispinis, Pellona flavipinnis and Hypophthalmus marginatus. Only Schizodon fasciatus, Serrassalmus spilopleura, Plagioscion squamosissimus and Hoplosternum littorale showed no seasonal variation in the condition factor. Despite the influence of reproductive characteristics, we can point at feeding habits as a biological trait that best explained the seasonal variation of the condition factor of fish species in the study area. Based on the local history, the hydrological cycle was considered atypical during the study period. Also, it was observed differences between cycles in the lake and in the main river. For most of the selected species, male and female seasonal variation in the condition factor showed similarities. Comparing juveniles and adults, the variation patterns of the two groups were different for the vast majority of species. / Marcada por uma alternância bem definida entre as fases terrestre e aquática, a várzea amazônica apresenta baixa sazonalidade climática, com oscilações diárias da temperatura superiores à anual e variação pouco pronunciada do fotoperíodo ao longo do ano. Esses ambientes são também caracterizados pelo padrão unimodal e previsível das enchentes com grande variação sazonal do nível da água. Para a ictiofauna da várzea, os efeitos diretos da variação do nível da água incluem severas modificações na composição das comunidades e na densidade das populações, condicionadas pelas alterações nas características limnológicas e na disponibilidade de alimentos. Tais variações sazonais, em termos de alimentação e respostas reprodutivas, podem ser expressas pelo fator de condição, indicador quantitativo do grau de bem-estar do peixe frente às condições de seu ambiente. Esse estudo visou gerar informações sobre a variação sazonal do fator de condição de espécies ictíicas nos lagos Jaitêua e São Lourenço, que compõem o Sistema do Lago Grande no município de Manacapuru, Estado do Amazonas. As coletas dos dados foram efetuadas mensalmente entre o período de Julho de 2006 e Julho de 2007. Calculado o fator de condição, as comparações entre períodos foram realizadas por métodos de ANOVA. Comparações entre sexo e entre juvenis e adultos foram feitas por teste t. Utilizou-se de PCA para identificar grupos de espécies com semelhanças na variação sazonal do fator de condição. Após análise crítica dos dados, foram selecionadas 13 espécies para estudo. A variação sazonal do fator de condição foi significante para Acestrorhynchus falcirostris, Triportheus albus, Triportheus auritus, Potamorhina altamazonica, Potamorhina latior, Pygocentrus nattereri, Serrassalmus altispinis, Pellona flavipinnis e Hypophthalmus marginatus. Apenas Schizodon fasciatus, Serrassalmus spilopleura, Plagioscion squamosissimus e Hoplosternum littorale não apresentaram variação sazonal. Apesar da influência de características reprodutivas, pode-se apontar o hábito alimentar como característica biológica que melhor explicou a variação sazonal do fator de condição das espécies ictíicas na área de estudo. Com base em séries históricas da localidade, o ciclo hidrológico foi considerado atípico durante o período de coleta. Observaram-se também diferenças entre ciclos no lago e no rio principal. Para a maioria das espécies selecionadas, machos e fêmeas apresentam variação sazonal no fator de condição semelhante. Comparando juvenis e adultos, os padrões de variação desses dois grupos foram diferentes para a grande maioria das espécies

During the recent summers, Gotland has suffered from drinking water shortage and due to the climate change, the water shortage can possible increase in the future. To find a solution, the Swedish Environmental Research Institute IVL and Region Gotland are going to build a testbed at Storsudret located on the south of Gotland, to investigate different sustainable solutions. One possible solution is to increase the water level in Lake Mjölhatteträsk, located at Storsudret, to increase the water storage. This master thesis has focused on the water balance of the lake to understand whether it is possible to store more water in the lake and how large areas that would be flooded in the event of an increase in the water level. This has been done using a combination of field data sampling with geophysical methods, hydraulic tests, water depth measurements, existing hydrometeorological data from Lantmäteriet and the Geological Survey of Sweden (SGU) and modelling with the tools MIKE SHE and MIKE HYDRO River created by DHI and also GIS. The result of this master thesis showed that there is a very thin soil layer with possibly high clay and silt content to the west of the lake. At the bottom of the lake, a thick clay layer exists which reduces the hydraulic connection between the lake and the surroundings. The potential to store and extract water in the sand layer in the west is therefore small. However, there is potential to produce enough water in the lake to meet the water demand at Storsudret, according to the model created in MIKE SHE. This would require a dam at a suggested location at the outflow with a height of 0.12 m. / Gotland har under de senaste åren lidit utav vattenbrist under somrarna och på grund av klimatförändringarna är det möjligt att vattenbristen kan komma att öka i framtiden. För att hitta en lösning har Svenska Miljöinstitutet (IVL) och region Gotland fått i uppgift att anlägga en testbädd på Storsudret på södra Gotland, där olika hållbara lösningar ska testas. En möjlig lösning är att höja vattennivån i sjön Mjölhatteträsk på Storsudret för att på så vis kunna lagra mer vatten. Den här masteruppsatsen har fokuserat på hur sjöns vattenbalans ser ut för att förstå om det är möjligt att lagra mer vatten i sjön och hur stora områden som skulle bli översvämmade vid en ökning av vattennivån. Detta har gjorts med hjälp av en kombination av fältstudier med geofysiska mätningar, hydrauliska tester, vattendjupmätningar och flödesmätningar tillsammans med digitala databaser från Lantmäteriet och Sveriges Geologiska Undersökning (SGU) samt modellering med verktygen MIKE SHE och MIKE HYDRO River som skapats av DHI och även GIS. Resultatet för den här masteruppsatsen visade att det finns ett mycket tunt jordlager med eventuellt högt ler och silt innehåll väster om sjön. Vid botten av sjön finns ett tjockt lerlager som minskar den hydrauliska förbindelsen mellan sjön och omgivningen. Potentialen att lagra och utvinna vatten i sandlagret i väst är därmed liten. Däremot finns det potential att producera tillräckligt med vatten i sjön för att kunna uppfylla vattenbehovet på Storsudret, enligt modellen skapad i MIKE SHE. Detta skulle innebära en dam vid en föreslagen punkt vid utflödet som har en höjd på 0.12 m.

Le but de ma thèse est de conduire et d’utiliser les premières observations atmosphériquesde surface du CO2, de l’O2, du CH4 et de la composition isotopique de la vapeur d’eau et desprécipitations dans la région peu instrumentée du sud du Groenland. Quelles informations cesobservations locales peuvent-elles nous apporter à la fois concernant les processus atmosphériqueslocaux et concernant le transport atmosphérique à grande échelle ? Peut-on en extrairedes informations sur les échanges entre la surface et l’atmosphère, qui constituent une part crucialedes cycles biogéochimiques du carbone et de l’eau ? L’interprétation paléoclimatique desenregistrements de carottes de glace au Groenland peut-elle bénéficier de ces observations ?Après une validation des observations menées à Ivittuut, sur la côte sud-ouest du Groenland,en regard de normes internationales de qualité, confirmant leur représentativité des variationsatmosphériques, j’ai commencé par interpréter ces observations en analysant leur variabilité àdifférentes échelles de temps et découlant de processus spécifiques. Ceci m’a permis de montrerque le site de mesure était très peu influencé par des phénomènes locaux : peu de sources localesde gaz à effet de serre, et de processus locaux agissant sur la composition isotopique de la vapeurd’eau. Cette caractéristique facilite l’attribution des variations observées à des changements detransport atmosphérique de grande échelle en lien avec des sources distantes.Pour comprendre les variations observées, je les ai mises en relation avec des observationsissues d’autres sites ainsi qu’avec des sorties de modèles atmosphériques de grande échelle. D’unepart, j’ai constaté que de nombreuses variations de la composition atmosphérique à l’échelle synoptiquepouvaient être expliquées par des modifications du transport atmosphérique de grandeéchelle. J’ai aussi pu identifier la représentativité spatiale de nos observations, et contribuerà l’évaluation de modèles atmosphériques de grande échelle. Enfin, un cas d’étude durant lavague de chaleur ayant affecté la totalité du Groenland durant l’été 2012 m’a permis de suivrele transport atmosphérique de masses d’air et d’observer en plusieurs points ses impacts sur lacomposition isotopique de la vapeur d’eau, notamment sur la conservation du signal d’excès endeutérium, qui n’avait jamais été observée auparavant.Enfin, la combinaison des observations et de la modélisation atmosphérique m’a permis demettre en évidence les contributions de l’observation atmosphérique en terme de documentationdes échanges entre la surface et l’atmosphère : par une attribution des valeurs observées auxsources potentielles identifiées par modélisation des masses d’air affectant la station pour le CH4et la composition isotopique de la vapeur d’eau, et par la comparaison des observations à dessimulations de transport direct de sources connues issues d’inventaires pour le CH4 ou modéliséespour le CO2 et l’O2 océanique. / South Greenland is a key region placed under Arctic and Northern Atlantic influences, whichis poorly documented in terms of atmospheric monitoring. The aim of my thesis is to conductand use the first regional atmospheric observations of CO2, O2, CH4 and isotopic compositionof water vapour and precipitation performed in Ivittuut, a coastal site in south-west Greenland.Which information can we infer from these atmospheric observations, in terms of localatmospheric processes and large scale atmospheric transport variations? Can we use these observationsto document the surface-air exchanges of these compounds, which represent an importantpart of the water and carbon biogeochemical cycles?After validating the observations regarding international precision recommandations, I havebeen able to analyse the variabilities at different time scales, resulting from different specificprocesses. This highlighted the fact the atmospheric composition of our site is weakly influencedby local processes, either for local greenhouse gases sources or small scale atmosphericvariations affecting water vapour isotopic composition. This facilitates the interpretation of ourobservations in terms of large scale atmospheric transport signals.To better understand the observed variations, I related our data series with other observationsoriginating from different sites, and with outputs from different atmospheric models. Ihave first witnessed the links between variations of atmospheric composition and large synopticscale atmospheric transport changes. Then, I have identified the spatial representativity of ourobservations and contributed to the evaluation of atmospheric models. The case study of astrong heat wave covering Greenland during summer 2012 allowed me to study the transport ofwater vapour within an air mass between different stations. It allowed me to provide the firstexperimental observation of deuterium excess conservation during atmospheric transport.Finally, combining observations and atmospheric simulations, I have documented surfaceairexchanges of the observed compounds: first by the attribution of observed values of CH4and water vapour isotopic composition to their simulated potential origins, secondly by thecomparison of observed variations with the direct simulation of atmospheric transport of eitherCH4 sources estimated from inventories or simulated CO2 and O2 air-sea fluxes from an oceanmodel.

In the Pacific Northwest (PNW), concern about the impacts of climate and land cover change on water resources, flood-generating processes, and ecosystem dynamics emphasize the need for a mechanistic understanding of the interactions between forest canopies and hydrological processes. A detailed measurement and modeling program during the 1999 and 2000 hydrologic years characterized hydrological conditions and processes in a 500-600 year old Douglas fir-western hemlock seasonal temperate rainforest. The measurement program included sub-canopy arrays of radiometers, tipping bucket rain gauges, and soil temperature and moisture probes, to supplement a vertical temperature and humidity profile within the forest canopy. Analysis of the precipitation interception characteristics of the canopy indicated that the mean direct throughfall proportion was 0.36, and the mean saturation storage was 3.3 mm. Evaporation from small storms insufficient to saturate the canopy comprised 19% of the net interception loss, and canopy drying and evaporation during rainfall accounted for 47% and 33% of the net loss, respectively. Results of the measurement program were used to modify the Simultaneous Heat and Water (SHAW) model for forested systems. Changes to the model include improved representation of interception dynamics, stomatal conductance, and within-canopy energy transfer processes. The model effectively simulated canopy air and vapor density profiles, snowcover processes, throughfall, soil water content profiles, shallow soil temperatures, and transpiration fluxes for both a calibration period and for an uncalibrated year. Soil warming at bare locations was delayed until most of the snowcover ablated due to the large heat sink associated with the residual snow patches. During the summer, simulated evapotranspiration decreased from a maximum monthly mean of 2.17 mm day����� in July to 1.34 mm day����� in September, as a result of declining soil moisture and net radiation. Our results indicate that a relatively simple parameterization of the SHAW model for the vegetation canopy can accurately simulate seasonal hydrologic fluxes in this environment. Application and validation of the model in other forest systems will establish similarities and differences in the interactions of vegetation and hydrology, and assess the sensitivity of other systems to natural and anthropogenic perturbations. / Graduation date: 2002

Large-scale atmospheric disturbances play important roles in determining the general circulation of the atmosphere during the North Pacific boreal winter. A number of scientific questions have been raised due to these disturbances’ spatial and temporal complexity as well as the hydrological implication associated with them. In this dissertation, the principal goal is to further improve our understanding of the atmospheric high frequency (HF) and intermediate frequency (IF) disturbances active over the North Pacific. The study focuses on their energetics, intraseasonal and interannual variability, and the resulting hydrological impact over the eastern North Pacific and Western U.S. including extreme events. To delineate the characteristics of HF and IF disturbances in the troposphere, we first derive a new set of equations governing the local eddy kinetic energy (EKE), and assess the critical processes maintaining local budgets of the HF and IF EKE. The diagnosis assesses the 3-D patterns of energy flux convergence (EFC), barotropic conversion (BT), baroclinic conversion (BC), and cross-frequency eddy-eddy interaction (CFEI). The local EKE budget analysis is followed by an investigation of the modulation of HF and IF eddy activity by different modes of low frequency climate variability. On interannual timescales, the response of various local energetic processes to El Niño-Southern Oscillation (ENSO) determines the HF and IF EKE anomalies and the role of CFEI process is important in producing these anomalies. Also on interannual timescales, winter precipitation deficits associated with suppressed cyclonic activity, i.e., negative HF EKE anomalies, are linked to severe droughts over the U.S. Southern Great Plain (SGP) region. The suppressed cyclonic activity is, in turn, tied to phase changes in the West Pacific (WP) teleconnection pattern. On intraseasonal timescales, variations in HF disturbances (a.k.a. storm tracks) over the North Pacific are closely coupled with tropical convection anomalies induced by the Madden-Julian Oscillation (MJO), and partly drive larger scale intraseasonal flow anomalies in this region through eddy-eddy interactions. Anomalous HF eddy activity induces subseasonal transitions between “wet” and “dry” regimes over the west coast of North America. Also on intraseasonal timescales, the East Asian cold surge (EACS) is found to provide a remote forcing of the winter precipitation anomalies in the western U.S. This modulation is achieved through “atmospheric rivers” (ARs), which are narrow channels of concentrated moisture transport in the atmosphere and are responsible for over 70% of the extreme precipitation events in the western U.S.. EACS effectively modulates the IF disturbance activity over the North Pacific, and the anomalous IF disturbances lead to the formation of an AR over the eastern North Pacific that ultimately induces precipitation anomalies in the western U.S. Analyses of the simulations from the NCAR Community Climate System Model version 4 (CCSM4) demonstrate that the connections among the EACS, AR and western U.S. precipitation are better captured by a model with higher spatial resolutions. The improved simulation of these connections is achieved mainly through a better representation of the IF disturbances, and the associated scale-interaction processes in the higher resolution model.

The West Pacific Warm Pool (WPWP) plays an important role in the global heat budget and global hydrologic cycle, so knowledge about its past variability would improve our understanding of global climate. Variations in WPWP precipitation are most notable during El Niño-Southern Oscillation events, when climate changes in the tropical Pacific impact rainfall not only in the WPWP, but around the globe. The stalagmite records presented in this dissertation provide centennial-to-millennial-scale constraints of WPWP precipitation during three distinct climatic periods: the Last Glacial Maximum (LGM), the last deglaciation, and the Holocene. In Chapter 2, the methodologies associated with the generation of U/Th-based absolute ages for the stalagmites are presented. In the final age models for the stalagmites, dates younger than 11,000 years have absolute errors of ±400 years or less, and dates older than 11,000 years have a relative error of ±2%. Stalagmite-specific 230Th/232Th ratios, calculated using isochrons, are used to correct for the presence of unsupported 230Th in a stalagmite at the time of formation. Hiatuses in the record are identified using a combination of optical properties, high 232Th concentrations, and extrapolation from adjacent U/Th dates. In Chapter 3, stalagmite oxygen isotopic composition (d18O) records from N. Borneo are presented which reveal millennial-scale rainfall changes that occurred in response to changes in global climate boundary conditions, radiative forcing, and abrupt climate changes. The stalagmite d18O records detect little change in inferred precipitation between the LGM and the present, although significant uncertainties are associated with the impact of the Sunda Shelf on rainfall d18O during the LGM. A millennial-scale drying in N. Borneo, inferred from an increase in stalagmite d18O, peaks at ~16.5ka coeval with timing of Heinrich event 1, possibly related to a southward movement of the Intertropical Convergence Zone (ITCZ). An inferred precipitation maximum (stalagmite d18O minimum) during the mid-Holocene in N. Borneo supports La Niña-like conditions and/or a southward migration of the ITCZ over the course of the Holocene as likely mechanisms for the observed millennial-scale trends. In Chapter 4, stalagmite Mg/Ca, Sr/Ca, and d13C records reflect hydrologic changes in the overlying karst system that are linked to a combination of rainfall variability and cave micro-environmental effects. Dripwater and stalagmite geochemistry suggest that prior calcite precipitation is a mechanism which alters dripwater geochemistry in slow, stalagmite-forming drips in N. Borneo. Stalagmite Mg/Ca ratios and d13C records suggest that the LGM climate in N. Borneo was drier and that ecosystem carbon cycling may have responded to the drier conditions. Large amplitude decadal- to centennial-scale variability in stalagmite Mg/Ca, Sr/Ca and d13C during the deglaciation may be linked to deglacial abrupt climate change events.

It has been historically assumed that most of the uncertainty associated with the aerosol indirect effect on climate can be attributed to the unpredictability of updrafts. We assess the sensitivity of cloud droplet number density to realistic variations in aerosol chemical properties and to variable updraft velocities using a 1-dimensional cloud parcel model. The results suggest that aerosol chemical variability may be as important to the aerosol indirect effect as the effect of unresolved cloud dynamics, especially in polluted environments. We next used a continuous flow streamwise thermal gradient Cloud Condesnation Nuclei counter (CCNc) to study the water-uptake properties of the ambient aerosol, by exposing an aerosol sample to a controlled water vapor supersaturation and counting the resulting number of droplets. The heat transfer properties and droplet growth within the CCNc were first modeled and experimentally characterized. We describe results from the MIRAGE field campaign at a ground-based site during March, 2006. Size-resolved CCN activation spectra and hygroscopic growth factor distributions of the ambient aerosol in Mexico City were obtained, and an analytical technique was developed to quantify a probability distribution of solute volume fractions for the CCN, as well as the aerosol mixing-state. The CCN were shown to be much less CCN active than ammonium sulfate, with water uptake properties more consistent with low molecular weight organic compounds. We also describe results from the GoMACCS field study, an airborne field campaign in Houston, Texas during August-September, 2006. GoMACCS tested our ability to predict CCN for highly polluted conditions with limited chemical information. Assuming the particles were composed purely of ammonium sulfate, CCN closure was obtained with a 10% overprediction bias on average for CCN concentrations ranging from less than 100 cm-3 to over 10,000 cm-3, but with on average 50% variability. Assuming measured concentrations of organics to be internally mixed and insoluble tended to reduce the overprediction bias for less polluted conditions, but led to underprediction bias in the most polluted conditions. Comparing the two campaigns, it is clear that the chemistry of the particles plays an important role in our ability to predict CCN concentrations.

La vapeur d’eau est le principal gaz à effet de serre de l’atmosphère et implique un processus de rétroaction climatique positif qui se traduit par une augmentation importante de l’humidité dans la troposphère dans les prochaines décennies. La vapeur d’eau joue également un rôle primordial dans le système climatique, notamment via le transport d’énergie de l’équateur vers les pôles. Malgré ceci, la compréhension des mécanismes qui contrôlent la distribution de la vapeur d’eau sur le globe reste insuffisante, ce qui se répercute sur les prédictions de l’évolution de notre climat. Depuis quelques années, les observations de la composition isotopique de la vapeur d’eau se sont révélées être particulièrement utiles pour aider à mieux comprendre les processus hydrologiques car les différents isotopologues de la vapeur d’eau (H216O, H218O, HDO) se comportent différemment selon les processus en jeu.<p>Dans cette perspective, les mesures de radiances du système terre-atmosphère dans l’infrarouge thermique par l’Interféromètre Atmosphérique de Sondage Infrarouge (IASI) à bord de la plateforme météorologique MetOp, peuvent fournir des observations du rapport isotopique δD (rapport HDO/H216O), à l’échelle globale et à haute résolution spatio-temporelle, pour autant que la restitution du rapport puisse être obtenue avec une précision suffisante.<p>Dans ce travail, nous présentons une méthodologie robuste et précise pour la restitution du profil de δD à partir des spectres IASI. Basée sur la méthode d’estimation optimale, elle consiste à appliquer des contraintes d’inversion adaptées afin d’obtenir des profils de δD fiables. Nous décrivons le choix de celles-ci et nous montrons que la méthode mise en place permet de fournir des profils de δD qui présentent un maximum de sensibilité dans la troposphère libre. L’adéquation de la méthode mise en place est ensuite évaluée grâce à une étude d’inter-comparaison avec des mesures dérivées de l’instrument spatial TES (Tropospheric Emission Spectrometer sur AURA) et FTIR localisés au sol. L’exactitude des profils IASI a aussi pu être déterminée grâce à des comparaisons avec des mesures in situ. <p>Dans une autre partie du travail, nous nous attachons à préciser les applications liées à l’utilisation des nouvelles mesures dans le domaine des géosciences. Nous documentons ainsi les capacités du sondeur IASI à fournir des mesures de δD à une résolution spatio-temporelle inégalée et décrivons les diverses distributions obtenues. Nous montrons et analysons notamment les premières cartes globales à haute résolution de δD dans la troposphère. Les mesures de δD et de l’humidité sont analysées conjointement à l’aide de modèles simples et permettent de démontrer la plus-value mesures de δD depuis les satellites. Parmi les résultats les plus significatifs, citons la mise en évidence de la signature isotopique des différentes sources de la vapeur d’eau (évaporation continentale/océanique), et celle de l’empreinte des différents processus hydrologiques qui contrôlent l’humidification de l’atmosphère (convection, mélange de masse d’air, ré-évaporation des gouttes de pluie). <p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, Arizona / The U.S. Environmental Protection Agency 's two-year 208 area-wide Water Quality Management Study for Pima County, Arizona, is discussed in terms of the specific problems of municipal wastewater effluent, industrial wastewater, urban stormwater runoff, land disposal of residual wastes, septic systems, and construction activities related to the City of Tucson urban area. The primary groundwater and the slow cycling of the hydrologic system in this arid urban environment reduce many water pollution problems to insignificant levels in the short term, (2) there does exist significant long-term pollution problems in the area. These problems include urban stormwater runoff and landfill leachate, and are related to the pollution of groundwater recharge and aquifer water supplies, and (3) there is a strong need for total water resource planning in arid urban areas which includes planning for wastewater reuse, water harvesting, and proper management of groundwater recharge systems.