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No. of bitstreams: 2 Dissertação - Evaldo de Melo Ferreira - 2015.pdf: 2077098 bytes, checksum: c520c1e3dd60261ddf1223135a5181be (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-02 / This work was carried out Agronomy School of the Federal University of Goiás, where there is a dam that has its water used for the purpose of industrial supply, human and also for the creation of exotic fish, not belonging to the Cerrado fauna. In 2011 the revegetation was initiated with native tree species, among these: baru (Dipteryx alata), pequi (Caryocar brasiliense), mutamba (Guazuma ulmifolia), murici (Byrsonima crassifólia), nóde- porco (Physocalymma scaberrimum), and apeiba (Apeiba albiflora). Before the land was occupied with the cultivation of vegetables, annual crops and forages. In association with some tree species were used green manures, which among other things promote soil unpacking and nutrient cycling through the roots. The main objective of this study was to diagnose the situation of the study area, including water body that is fueled by Córrego Samambaia. Measurements were made of height and diameter of tree species for twelve months. In addition there collecting dam water samples where analyzed parameters pH, conductivity, total P and heavy metals. In July of 2014 and December of that year, analyzes were made of turbidity, color, biochemical oxygen demand (BOD) and dissolved oxygen (DO). The parameters were evaluated according to the recommendations in the Standard Methods For Examination of Water & Wastewater (APHA, 2012) and these were performed in the Soil Analysis Laboratory, Substrate and Plant Nutrition (Lassnut) in the Agronomy School, and the use of Sanitation Laboratory of the School of Civil Engineering, both from the Federal University of Goiás. It also carried out physico-chemical analysis of soil. These were performed at Lassnut and also at the Soil Physics Laboratory EA-UFG. Monitoring carried out in September 2013 to August 2014, some plants had good response in relation to the use of green manures, but others had high mortality during the study, as the case of the pequi. The competition between alien and native was reduced, which increased overall survival. Elements such as Mn showed no significant difference in all treatments during evaluation’s period. The replacement of leguminous plants where there has been death is one of the alternatives to reduce compression levels. Macro and micro pores values were similar, but for texture area showed differences. For penetration resistance tests (PR) made in an area with green manure and one without legumes species, the largest PR values were found in the area without green manure. The water body receives the discharge of sewage illegally occupied homes. Parameters such as electric conductivity, were stable during the twelve months of study. The results for DO and BOD are outside the recommended by CONAMA’s determination, Nº 357. / O presente trabalho foi realizado na Escola de Agronomia da Universidade Federal de Goiás, onde existe uma represa cuja água utilizada para fins de abastecimento industrial, humano e também para a criação de peixes exóticos, não pertencentes a fauna do Cerrado. Em 2011 foi iniciado um processo de revegetação da área com espécies arbóreas nativas, entre essas: baru (Dipteryx alata), pequi (Caryocar brasiliense), mutamba (Guazuma ulmifolia), murici (Byrsonima crassifólia), nó-de-porco (Physocalymma scaberrimum) e apeiba (Apeiba albiflora). Antes o solo era ocupado com o cultivo de hortaliças, culturas anuais e forrageiras. Em consórcio com algumas espécies arbóreas foram utilizados adubos verde, que entre outros benefícios promovem a descompactação do solo e ciclagem de nutrientes por meio das raízes. O objetivo principal do presente trabalho foi diagnosticar a situação da área em estudo, incluindo o corpo hídrico que é abastecido pelo Córrego Samambaia. Foram realizadas medições de altura e diâmetro das espécies arbóreas, durante doze meses. Além disso ocorreram coletas de amostras da água da represa, onde analisou-se os parâmetros pH, condutividade, P total e metais pesados. Nos meses de julho de 2014 e dezembro do mesmo ano, foram realizadas análises de turbidez, cor, demanda bioquímica de oxigênio (DBO) e oxigênio dissolvido (OD). Os parâmetros foram avaliados de acordo com o preconizado no Standard Methods For Examination of Water & Wastewater (APHA, 2012) e foram realizadas no Laboratório de Análises de Solos, Substrato e Nutrição de Plantas (Lassnut) na Escola de Agronomia (EA), além do uso do Laboratório de Saneamento da Escola de Engenharia Civil, ambos pertencentes à Universidade Federal de Goiás. Foram também realizadas análises físico-químicas do solo. Essas foram realizadas no Lassnut e também no Laboratório de Física do Solo da EA-UFG. No monitoramento realizado de setembro de 2013 à agosto de 2014, algumas plantas tiveram boa resposta em relação ao uso dos adubos verdes, porém outras tiveram alta mortandade durante o estudo, como foi o caso do pequi. A competição entre espécies exóticas e as nativas foi reduzida, o que aumentou em geral a sobrevivência. Elementos tais como Mn não apresentaram diferença significativa em todos os tratamentos nos períodos de avaliação. A reposição das espécies leguminosas onde houve morte de plantas é uma das alternativas para a redução dos níveis de compactação. Os valores de macro e micro poros foram parecidos, porém para textura a área apresentou diferenças. Para os testes de resistência a penetração (RP) feitos em área com adubo verde e outra sem as espécies leguminosas, os maiores valores de RP foram encontrados na área sem adubos verdes. O corpo hídrico recebe o despejo de esgotos de residências ocupadas irregularmente. Parâmetros tais como condutividade elétrica da água, apresentaram-se estáveis durante os 12 meses de estudo. Os resultados para OD e DBO estão fora do preconizado pela resolução de Nº 357 do Conama.

De nos jours, la durabilité des activités humaines devient une préoccupation majeure dans le monde entier. Il s’agit d’évaluer ces activités non seulement en matière d’efficacité et de productivité, mais aussi en ce qui concerne leurs durabilités économique, sociale, environnementale, etc. Pour cela, les experts de ces différents domaines doivent travailler en collaboration. Dans ce contexte, les sociétés humaines sont confrontées à plusieurs défis majeurs qui sont les suivants : (1) traiter de grandes quantités d’informations (« big data »), (2) évoluer dans un monde réel dynamique et imparfait, (3) prévoir et évaluer les états futurs de ses activités.Les recherches que nous avons menées dans cette thèse contribuent plus particulièrement au domaine de l’ingénierie des systèmes de décision en univers incertain. Nous prenons comme objet d'étude général le domaine des systèmes socio-environnementaux, et plus particulièrement le domaine pluridisciplinaire de l’agriculture. Nous proposons une approche systémique pour l’optimisation durable des systèmes socio-environnementaux : (1) la méta-modélisation des systèmes socio-environnementaux, (2) la représentation générique de l’imperfection des informations qui circulent dans ces systèmes, associée à un modèle de décision en contexte incertain et enfin (3) la simulation et l’évaluation de ces systèmes en environnement dynamique en vue de prises de décisions par des experts, que nous avons illustrée par un modèle d’architecture orientée services ainsi que des études de cas appliquées au domaine de l’agriculture. / Nowadays, the sustainability of human activities is a major worldwide concern. The challenge is to evaluate such activities not only in terms of efficiency and productivity, but also in terms of their economic, social, environmental, etc. durability. For this, the experts of these areas need to work collaboratively. In this context, human societies are facing several major challenges such as: (1) process a large amount of information whose volume increases exponentially (“big data”), (2) live in a both dynamic and imperfect real world, (3) predict and assess future states of its activities.The researches we have conducted in this thesis contribute in particular to the domain of decision systems engineering under uncertainty. We have chosen the field of general socio-environmental systems as subject of study, particularly the multidisciplinary field of agriculture. We propose a systemic approach for the sustainable optimization of socio-environmental systems: (1) the meta-modeling of socio-environmental systems, (2) the generic representation of data imperfection flowing in such systems, associated to a decision model in uncertain environment and finally (3) the simulation and the assessment of such systems in dynamic environment for the purpose of decision making by experts which we have illustrated by both a service-oriented architecture model and case studies applied to the agriculture domain.

Thesis (M. Eng. in Ocean Engineering)--Joint Program in Marine Environmental Systems (Massachusetts Institute of Technology, Dept. of Ocean Engineering; and the Woods Hole Oceanographic Institution), 1998. / Includes bibliographical references (leaves 70-71). / Optical imaging techniques can be used to provide a better understanding of the physical properties of particle clouds. The purpose of this thesis is to design, perform and evaluate a set of experiments using optical imaging techniques to characterize parameters such as shape factor and entrainment coefficient which govern the initial descent phase of particle clouds in water. Several different aspects of optical imaging are considered and evaluated such as the illumination, camera, and data acquisition components. A description of the experimental layout and procedure are presented along with a description of the image processing techniques used to analyze the data collected. Results are presented from a set of experiments conducted with particle sizes ranging from 250 to 980um. A shape factor is used to demonstrate how the cloud's shape changes from approximately spherical to approximately hemispherical over depth. The entrainment coefficient is shown to vary both as a function of depth and particle size diameter. The experimental cloud velocity is compared to the output of a simplified version of the model, STFATE, used to simulate the short term fate of dredged materials in water. This analysis provides a method of evaluating the experimental results and examining the feasibility of using the experimental data to refine the input parameters to the model. / by Elizabeth J. Bruce. / M.Eng.

Dust is a critical component of the Earth System. The central and western Sahara (CWS) is the dustiest place on Earth during the northern hemisphere summer. Understanding patterns and causes of spatial and temporal variability of dust presence here is essential for its reliable simulation in numerical models of weather and climate. Four papers in this thesis contribute to that objective, utilising a combination of high temporal resolution satellite data and global atmospheric reanalyses for June – August 2004 – 2010 inclusive. The first paper develops an objective dust detection scheme for the CWS using data from the Spinning Enhanced Visible and Infrared Imager (SEVIRI), which are available every 15 minutes around the clock. These data have shed valuable insight on CWS dust processes, but their subjective application has to date limited their range of applications. The SEVIRI dust flag (SDF) developed here is evaluated against other widely used surface and satellite derived indicators of dustiness and it is found to reliably detect the presence of moderate-heavy dust loadings. The distribution of dust each summer is presented, revealing a high degree of interannual variability in overall dust coverage. The second paper utilises SDF to create an objective, high spatial resolution dust source map, based on the automated tracking of individual dust plumes. The most active sources are associated predominantly with palaeo-lakes and outwash plains, typically around the Saharan mountains. There is a clear intraseasonal progression of active source areas, controlled by regional climatology. The tracking scheme describes the transport trajectory of dust events following their initiation and the spatial association with deep convection at this time, revealing a clear regional divide in the relative importance of known meteorological mechanisms that drive dust emission from the dominant sources. The third paper uses an unsupervised clustering algorithm to classify maps of daily dust presence frequency and identify patterns of intraseasonal variability in CWS dust coverage. The resulting idealised dust states vary according to frequency of dust occurrence and its location, demonstrating a clear progression in preferred dust location from June – August and preferred state transitions from one day to the next. High daily dust occurrence frequency corresponds to an advanced West African Monsoon flow and low daily dust occurrence frequency corresponds to a Harmattan-dominated CWS. The overall location of the dust is linked to the location of the Sahara Heat Low, which changes as the summer progresses. The final paper addresses interannual variability in summertime dust presence frequency by comparing the 2 years with highest (2005) and lowest (2008) dust presence. The key difference is the occurrence of 3 multi-day periods in 2005 characterised by anomalously high dust presence. Case study comparison with the 3 periods of highest dust presence in 2008 identifies the anticyclonic circulation of the midtroposphere as a key control on dust duration over the CWS, dictating whether emitted dust is efficiently transported away from the CWS or whether it remains in suspension over the region for prolonged periods of time, up to several days in the anomalously dusty periods of 2005.

This thesis examines the relationship between environmental stress and human mobility with a view to understanding the impacts of climate change on human migration. Using a conjuncture of political ecology and migration theory, it firstly explores the literature on 'environmental refugees' identifying a distinction between general agreement on the existence of a relationship between environmental stress and migration, and debate over the appropriateness of the 'environmental refugee' as a suitable means for representing that relationship. Secondly this conjuncture is used to examine accounts from farmers and migrants in northern Ethiopia, with a focus on understanding how environmental and non-environmental factors interact to shape mobility decisions in a context of environmental stresses, thought analogous to those predicted to accompany future climate change. The principal finding of the study is that although environmental stress matters in mobility decisions, it does so due to the context of non-environmental factors in which it occurs, not in spite of them. With this in mind the work provides a framework of additive, vulnerability, enabling and barrier effects as a means for elaborating our understanding of how environmental and non-environmental factors interact to determine mobility strategies in a context of environmental stress. Focussing on the role of non-environmental factors, the work reveals that while biophysical features operate at a macro-scale to shape mobility decisions, these decisions are determined by non-environmental features operating at a micro-scale. The research then traces differences in the existence of these micro-scale, non-environmental, factors across two field sites, finding that their origins lie in both historical and contemporary forces of regional and global political economy. As such, the work concludes that understanding the relationship between climate change and human migration will require a contextualisation of that relationship within this broader framework.

The recent revival of debates concerning livestock development in Africa follows the more widespread acceptance of paradigm shifts within rangeland science, and maintaining pastoral mobility is now recognised as fundamental for the future survival of pastoralism and sustainability of dryland environments. However, in southern Africa communal pastoral drylands continue to be enclosed and dissected by large-scale barrier fences designed to control livestock diseases, thus protecting lucrative livestock export agreements. This interdisciplinary research examines the extent to which these veterinary cordon fences have changed people’s access to, and effective management of, natural resources in northern Botswana and how fence-restricted resource use by livestock, wildlife and people has changed the natural environment. Critical political ecology informed the approach, given its emphasis on socio-political and historical influences on resource access, mobility and user relationships. This enabled the biophysical effects of social changes to be investigated fully, thereby moving beyond a tradition of discipline-based studies often resulting in severely repressive rangeland policies. The research demonstrates how enclosure by veterinary cordon fences restricts patterns of resource access and mobility within pastoral drylands, with serious implications for both social and environmental sustainability. Enclosure increases the vulnerability of people to risks and natural hazards, while resource access constraints and pastoral adaptations to enclosure have favoured the increasing commercialisation of livestock production, thus obstructing pathways into pastoralism. While widespread environmental change in livestock areas cannot be attributed thus far to enclosure, the curtailment of wild migratory herbivores at the wildlife–livestock interface has caused some large-scale structural vegetation changes and there are indications that fence induced sedentarisation could be accentuating existing degradation trends. Given these changes, future rangeland policies in Africa should be aware of the social and environmental impacts associated with export-led disease management infrastructure and consider alternative, less intrusive, approaches to livestock development and disease control in extensive pastoral drylands.

In boreal summer, satellite measurements show that the central Sahara is the dustiest region of the planet. However, ground-based observations of the central Sahara have been limited to its outer edges, leaving a void in observations approximately 1 million km² in area. The Fennec Project has been the first campaign to instrument this remote but climatologically important region. This thesis uses these new observations to detect and explain the atmospheric mechanisms that make the central Sahara the summer global dust maximum. Four atmospheric mechanisms are found to cause dust storms in the central Sahara in June 2011 and June 2012. These are cold pool outflows, low-level jets (LLJs), monsoon surges and dry convective plumes. Dust may be emitted locally by these phenomena, or be advected, principally by cold pools. In both field seasons, dust emission by cold pool outflows is the most important dust mechanism, causing roughly half of the total dust loadings at the Fennec supersite of Bordj-Badji Mokhtar (BBM), the closest station to the dust maximum. The second most important mechanism is dust advection by cold pools (roughly 30% dust at BBM), followed by dust emission by monsoon surges, LLJs and finally dry convective plumes (only 2% dust at BBM). Although June 2012 was significantly more dusty than June 2011, the relative importance of the different atmospheric dust mechanisms at BBM did not change. At the automatic weather stations (AWSs) across the remote desert, cold pools and LLJs are by far the most frequently detected atmospheric dust mechanisms. LLJs are particularly common in the Atlantic Inflow in western Mauritania and in the north-easterly Harmattan in western Algeria. Cold pools are much more frequent at BBM, the station under the greatest moist monsoon influence, than at the AWSs to the north. Detection of advected dust is a particular difficulty without dedicated dust-detection instrumentation or human observers (e.g. at the AWSs). Detection of dust emission mechanisms can be very successful with only routine ground observations and satellite measurements, but quantifying the associated dust burden without dedicated dust instruments is problematic. The choice of instrumentation for dust measurement is crucial. Because cold pool outflows - the most important dust mechanism - frequently occur at night or under cloud, sun photometers miss about half of cold pool dust. Lidars have the advantage of providing height resolved dust profiles, but they suffer from attenuation in thick dust. The nephelometer proved to be the most reliable dust instrument. Although LLJs occurred on 21/28 mornings at BBM in June 2011, only five of these jets led to dust emission. Calculations of momentum exchanges through the atmospheric column show that momentum mix-down from the jet core is the cause of dust emission on these occasions, but that the LLJ has to be particularly strong (≥ 16 m s^-1) to result in dust emission at the surface. Met Office Africa-LAM underestimates monsoon LLJ wind profiles and ERA-Interim reanalysis underestimates both monsoon and Harmattan LLJ wind profiles. At the surface, the Met Office Africa-LAM and GLOBAL models significantly underpredict the frequency of observed wind speeds &gt6 m s^-1. This will cause them to significantly underestimate dust emission, as emission is a threshold process proportional to the cube of wind speed. A particularly interesting implication of the research presented here is that the central Sahara is likely much more dusty than previously thought. This is because almost all of the techniques currently used to study dust in the region are systematically biased to result in underestimates of dust burden. Cold pools are the most important dust mechanism but, since they rarely occur during the daytime or in cloud-free conditions they are often missed by sun photometers. Many will be missed by satellites that cannot retrieve below cloud and satellites that pass over the Sahara in daylight hours (e.g. the A-train). A commonly-used satellite dust detection algorithm often misses dust under moist (i.e. cold pool) conditions. Cold pools cannot be simulated by models without explicit convection, which requires very high spatial resolution. Finally, the numerical models assessed here significantly underpredict the frequency of wind speeds over the dust emission threshold. The Sahara is probably much dustier than current estimates suggest.

The relative contributions of biome history and geological setting to historical assembly of species richness in biodiversity hotspots remain poorly understood. The tropical Andes is one of the world’s top biodiversity hotspots, and with its diverse biomes and the relatively recent but dramatic uplift, the Andes provides an ideal study system to address these questions. To gain insights into the historical species assembly of the tropical Andes, this study focuses on investigating patterns of plant species diversification in the Andean seasonally dry tropical forest (SDTF) biome. Three plant genera are used as study groups: Amicia (Leguminosae, Papilionoideae), Tecoma (Bignoniaceae), and Mimosa (Leguminosae, Mimosoideae). Species limits are re-evaluated to enable dense sampling of species and intraspecific diversity for phylogeny reconstruction for each group. Time-calibrated phylogenies for Amicia and Mimosa are presented and used to determine patterns of species diversification in time and space. For Tecoma, incongruence between nuclear and chloroplast gene trees precludes straightforward estimation of a species tree and this incongruence is attributed to possible reticulation caused by hybridization. Divergence time estimates and patterns of diversification for Amicia and Mimosa are compared with other Andean SDTF groups (Cyathostegia, Coursetia, Poissonia; Leguminosae) using isolation by distance and phylogenetic geographic structure analyses. Consistently deep divergences between sister species and high geographic structure across all five groups suggest that Andean SDTF lineages have persisted over the past 10 million years (My) with high endemism driven by dispersal limitation, caused by geographic isolation, following the most recent episode of rapid mountain uplift 5-10 My ago. This prolonged stasis of the Andean SDTF biome is in line with Miocene fossil and paleoclimate evidence. Finally, wider analyses of the contrasting evolutionary timescales of older SDTF and more recent high-altitude grassland diversity suggest that the exceptional plant species diversity in the Andes is the outcome of highly heterogeneous evolutionary histories reflecting the physiographical heterogeneity of the Andean biodiversity hotspot.

The Martian atmosphere is of great scientific interest, both because of its similarity to Earth’s atmosphere, and because of its relevance to exploration of Mars. Although satellite instruments have provided a wealth of atmospheric data, they have provided little information about the atmospheric boundary layer. Conditions in the lowest few metres of the Martian atmosphere are perhaps the most directly interesting to humans, as this is the portion of our own atmosphere with which we have the most contact. In this thesis is described the design, calibration and operations planning for a new wind sensor for use on Mars. This sensor is lighter and smaller than previous Mars wind sensors. At the time of writing, the wind sensor is on its way to Mars as part of the science payload of Beagle 2, a small exobiology lander due to arrive in December 2003. The Beagle 2 wind sensor (B2WS) is a hot-film anemometer. Three platinum films are equally spaced around the surface of a vertical cylinder. A known current is dissipated in each film, heating the film 40-80°C above the ambient gas temperature. The film temperature is obtained by measuring its resistance. An effective heat transfer coefficient is then calculated for each film. A novel scheme has been developed which allows calculation of a wind vector from the differences between these heat transfer coefficients, rather than from their average. This makes the measured wind vector less prone to common-mode errors such as uncertainties in air temperature or sky temperature. The sensor was calibrated in a low density wind tunnel, optimised to provide stable winds of air or carbon dioxide at Martian pressures (5 – 10 mbar) and speeds (0.5 – 30 m/s). The flow field in the test section was calculated using analytical and finite element modelling techniques, and validated experimentally using a pitot probe. This facility’s stability and accuracy represent a significant improvement over previous calibration facilities. An analytical model of heat flow in the sensor has been developed in order to permit correction for conditions which may be encountered on Mars, but were not tested for in the wind tunnel. The wind sensor’s performance in a real Martian atmosphere is simulated using wind and temperature data from a previous Mars lander. The position of the wind sensor position at the end of Beagle 2's motorised arm allows several new possibilities for wind measurement on Mars that were unavailable in previous missions. The height of the wind and air temperature sensors can be adjusted to any height between 20 and 95 cm above the ground. The temperature sensor can be scanned horizontally and vertically above the lander to study convective updrafts above the heated lander. Planned operations sequences on Mars are discussed.

If as argued the Mediterranean consisted in Antiquity of a unity determined by similar environmental factors and crises which were mitigated through established networks of trade and exchange, the border regions of the Roman Mediterranean, particularly to the South and East, were characterised by a radically different environment. This thesis focuses on the development of three of the arid regions bordering the ancient Mediterranean, namely the Fazzan oases in the Libyan Sahara, the Eastern Desert of Egypt and the region of Palmyra in Syria. These arid regions have received considerable archaeological attention in recent years, and a review of them will highlight the factors which enabled these regions to interact with the Roman Empire through trading dynamics, but also through the development of local resources. Central questions within this thesis concern the extent to which the environment would have tailored the potential of these regions, and if the existence of trade routes and social networks both affected and were affected by settlement and exploitation patterns in the region. Trade was created by geographically much broader social requirements for foreign or exotic goods, yet was restricted by the possibility to pass through these regions. Developments were conditioned by the constant need for balance between the state as a power enforcing and representing peace and security and local entities, and what the local social organisation had to offer in term of rent and stability to the state as an institution. After an introduction (Chapter 1) delineating the aims of the thesis, Chapter 2 defines influential theories and models that will be considered for this thesis, namely environmental factors, social networks and institutional economics. The archaeological evidence is then discussed in each relevant chapter: Chapter 3: The Libyan Sahara; Chapter 4: The Eastern Desert of Egypt; Chapter 5: Palmyra. Chapter 6 discusses major factors that may work as explanations for the development of agriculture, the exploitation mineral resources, and trade in these regions. The choice of regions both inside and outside the Roman Empire also allows a discussion on the rise of economic activities linked to the imperial economy. As such, the thesis moves away from a romano-centric perspective and proposes to look instead for internal factors, such as the development of complex societies with organisational frameworks and social networks which enable them to overcome the challenges of their geo-climatic settings. This study concludes that the developments identified in each chapter were not a factor of environmental changes but human agency. The state, or private individuals or communities successfully organised the resources necessary to integrate the regions into wider networks of intense trade in the imperial period. These concerned both physical infrastructure, and the development of far-reaching social networks.