925 resultados para Land-use mix
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Tese de Doutoramento em Ciências (Especialidade de Geologia)
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Dissertação de mestrado integrado em Engenharia Civil
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Relatório de estágio de mestrado em Geografia (área de especialização em Planeamento e Gestão do Território)
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Dissertação de mestrado em Engenharia Urbana
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Se propone analizar el efecto del uso productivo en el Chaco Árido de la provincia de Córdoba, mediante la aplicación de indicadores de sustentabilidad relacionados con la calidad de la materia orgánica y la liberación de nutrientes en el suelo, con la finalidad de aportar a un tema de suma interes para la provincia de Córdoba como es la formulación de criterios y pautas de manejo para la implementación de la Ley de Bosques (N° 26331). Se trabajará en la localidad de San Miguel en el departamento Pocho, en un sitio de bosque no disturbado y en tres sistemas productivos: desmonte selectivo con implantación de pasturas; desmonte total con agricultura bajo riego y desmonte total sobrepastoreado. En cada sitio se medirá “in situ” la emisión de CO2 y se tomaran muestras de suelo a las que se les determinará: a) contenido de materia orgánica total (MO), b) contenido de sustancias húmicas (SH), diferenciando ácidos húmicos (AH) y fúlvicos (AF), c) abundancia y actividad de microorganismos nitrificadores y d) propiedades químicas de los AH y AF. Se calcularán los siguientes índices de sustentabilidad a) materia orgánica biodisponible (MOB=MO–SH); b) índice de humificación (IH=SH/MO); c) tipo de humus (TH=AF/AH; d) índice de mineralización de C (IMC=CO2/MO); e) índice de nitrificación (IN=actividad/abundancia); y f) índice de estabilidad de las fracciones humificadas: compuestos aromáticos/ alifáticos. Los datos serán analizados estadísticamente mediante ANOVA y comparación de medias por LSD (P<0.05) y tests multivariados. We proposed analyze the effect of land use in Arid Chaco of Cordoba province, using sustainability indicators related to organic matter quality and nutrient release in soil, with the aim to formulate management criteria for the implementation of the Ley de Bosques (N° 26331) in Córdoba province. The study will be conducted in San Miguel village in Pocho department, in one undisturbed forest site and three productive systems: selective clearing with grass sowing; total clearing with irrigation agriculture and total clearing with overgrazed. In each site "in situ" CO2 emission will be measured and soil samples will be taken, in which the following parameters will be determined: a) total organic matter content (MO), b) humic substances content (SH), in humic acids (AH) and fulvic acids (AF), c) abundance and activity of nitrifier microorganisms and d) chemical properties of AH and AF. The sustainability indexes will be calculated: biodisponible organic matter (MOB=MO–SH); b) humification index (IH=SH/MO); c) humus type (TH=AF/AH; d) C mineralization index (IMC=CO2/MO); e) nitrifying index (IN=activity/abundance); and f) humic fractions stability index: aromatic/aliphatic compounds. The data will be statistically analyzed by ANOVA and the means will be compared by LSD (P<0.05) and multivariate tests.
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Las actividades agropecuarias ejercen diferentes presiones sobre los recursos naturales. Esto ha llevado, en algunas áreas, a un deterioro del suelo que provoca un impacto sobre la sustentabilidad en los sistemas agropecuarios. Para evaluar la degradación del suelo se han propuesto listas de indicadores, sin embargo, se carece de una herramienta metodológica robusta, adaptada a las condiciones edafoclimáticas regionales. Además, existe una demanda de productores e instituciones interesados en orientar acciones para preservar el suelo. El objetivo de este proyecto es evaluar la degradación física, química y biológica de los suelos en agroecosistemas del centro-sur de Córdoba. Por ello se propone desarrollar una herramienta metodológica que consiste en un set de indicadores físicos, químicos y biológicos, con valores umbrales, integrados en índices de degradación, que asistan a los agentes tomadores de decisiones y productores, en la toma de decisiones respecto de la degradación del suelo. El área de trabajo será una región agrícola del centro-sur de Córdoba con más de 100 años de agricultura. La metodología comienza con la caracterización del uso del territorio y sistemas de manejo, su clasificación y la obtención de mapas base de usos y manejos, mediante sensores remotos y encuestas. Se seleccionarán sitios de muestreo mediante una metodología semi-dirigida usando un SIG, asegurando un mínimo de un punto de muestreo por unidad de mapeo. Se elegirán sitios de referencia lo más cercano a una condición natural. Los indicadores a evaluar surgen de listas propuestas en trabajos previos del grupo, seleccionados en base a criterios internacionales y a adecuados a suelos de la región. Se usarán indicadores núcleo y complementarios. Para la obtención de umbrales, se usarán por un lado valores provenientes de la bibliografía y por otro, umbrales generados a partir de la distribución estadística del indicador en suelos de referencia. Para estandarizar cada indicador se definirá una función de transformación. Luego serán ponderarán mediante análisis estadísticos mulivariados e integrados en índices de degradación física, química y biológica, y un índice general de degradación. El abordaje concluirá con el desarrollo de dos instrumentos para la toma de decisiones: uno a escala regional, que consistirá en mapas de degradación en base a unidades cartográficas ambientales, de uso del territorio y de sistemas de manejo y otro a escala predial que informará sobre la degradación del suelo de un lote en particular, en comparación con suelos de referencia. Los actores interesados contarán con herramientas robustas para la toma de decisiones respecto de la degradación del suelo tanto a escala regional como local. Agricultural activities exert different pressures on natural resources. In some areas this has led to soil degradation and has an impact on agricultural sustainability. To assess soil degradation a robust methodological tool, adapted to regional soil and climatic conditions, is lacking. In addition, there is a demand from farmers and institutions interested in direct actions to preserve the soil. The objective of this project is to assess physical, chemical and biological soil degradation in agroecosystems of Córdoba. We propose to develop a tool that consists of a set of physical, chemical and biological indicators, with threshold values, integrated in soil degradation indices. The study area is a region with more than 100 years of agriculture. The methodology begins with the characterization of land use and management systems and the obtaining of base maps by means of remote sensing and survey. Sampling sites will be selected through a semi-directed methodology using GIS, ensuring at least one sampling point by mapping unit. Reference sites will be chosen as close to a natural condition. The proposed indicators emerge from previous works of the group, selected based on international standards and appropriate for the local soils. To obtain the thresholds, we will use, by one side, values from the literature, and by the other, values generated from the statistical distribution of the indicator in the reference soils. To standardize indicators transformation functions will be defined. Indicators will be weighted by mans of multivariate analysis and integrated in soil degradation indices. The approach concluded with the development of two instruments for decision making: a regional scale one, consisting in degradation maps based on environmental, land use and management systems mapping units; and an instrument at a plot level which will report on soil degradation of a particular plot compared to reference soils.
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This research looked at the scientific evidence available on climate change and in particular, projections on sea level rise which ranged from 0.5m to 2m by the end of the century. These projections were then considered in an Irish context. A review of current policy in Ireland revealed that there was no dedicated Government policy on climate change or coastal zone management. In terms of spatial planning policy, it became apparent that there was little or no guidance on climate change either at a national, regional or local level. Therefore, to determine the likely impacts of sea level rise in Ireland based on current spatial planning practice and policy, a scenario-building exercise was carried out for two case study areas in Galway Bay. The two case study areas were: Oranmore, a densely populated town located to the east of Inner Galway Bay; and Tawin Island, a rural dispersed community, located to the south east of Inner Galway Bay. A ‘best’ and ‘worse’ case scenario was envisaged for both areas in terms of sea level rise. In the absence of specific climate change policies it was projected that in the ‘best’ case scenario of 0.5m sea level rise, Tawin Island would suffer serious and adverse impacts while Oranmore was likely to experience slight to moderate impacts. However, in the ‘worse’ case scenario of a 2m sea level rise, it was likely that Tawin Island would be abandoned while many houses, businesses and infrastructure built within the floodplain of Oranmore Bay would be inundated and permanently flooded. In this regard, it was the author’s opinion that a strategic and integrated climate change policy and adaptation plan is vital for the island of Ireland that recognises the importance of integrated land use and spatial planning in terms of mitigation and adaptation to climate change.
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The main objective of this thesis on flooding was to produce a detailed report on flooding with specific reference to the Clare River catchment. Past flooding in the Clare River catchment was assessed with specific reference to the November 2009 flood event. A Geographic Information System was used to produce a graphical representation of the spatial distribution of the November 2009 flood. Flood risk is prominent within the Clare River catchment especially in the region of Claregalway. The recent flooding events of November 2009 produced significant fluvial flooding from the Clare River. This resulted in considerable flood damage to property. There were also hidden costs such as the economic impact of the closing of the N17 until floodwater subsided. Land use and channel conditions are traditional factors that have long been recognised for their effect on flooding processes. These factors were examined in the context of the Clare River catchment to determine if they had any significant effect on flood flows. Climate change has become recognised as a factor that may produce more significant and frequent flood events in the future. Many experts feel that climate change will result in an increase in the intensity and duration of rainfall in western Ireland. This would have significant implications for the Clare River catchment, which is already vulnerable to flooding. Flood estimation techniques are a key aspect in understanding and preparing for flood events. This study uses methods based on the statistical analysis of recorded data and methods based on a design rainstorm and rainfall-runoff model to estimate flood flows. These provide a mathematical basis to evaluate the impacts of various factors on flooding and also to generate practical design floods, which can be used in the design of flood relief measures. The final element of the thesis includes the author’s recommendations on how flood risk management techniques can reduce existing flood risk in the Clare River catchment. Future implications to flood risk due to factors such as climate change and poor planning practices are also considered.
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The taxonomic composition and diversity of assemblages of Ephemeroptera nymphs of four lotic environments in the central region of State of Rio Grande do Sul, a subtropical area in southern Brazil, were evaluated. Samplings were done monthly, with a Surber sampler, from June 2001 to May 2002, in the Jacuí River and three of its tributaries. The total number of nymphs collected in the four sampling sites was 11,007 in five families and 19 genera, of these, 11 are new records for the State. The highest diversity occurred in Point 4 (H'=2.41) and the lowest in Point 2 (H'=1.69). Point 4 had the highest environmental stability, conservation of the riparian vegetation and the lowest anthropic impact, while Point 2 presented a large environmental simplification due to a direct anthropic influence (e.g. domestic sewerage, trampling by cattle). The diversity of nymphs observed in the total area is high, compared to the estimated maximum theoretical diversity; a result of the high evenness and richness recorded. Rarefaction curves, calculated for a sample of 1,018 specimens, showed a similar expectation of richness for the four sampling sites. This result seems to be associated with the overall environmental homogeneity of the region caused by long-term alterations (land use and deforestation). In summary, higher diversity of Ephemeroptera nymph assemblages seems to be associated with habitat complexity, a good vegetation cover and a lower anthropic influence.
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ABSTRACT One of the most important effects derived from the intensive land use is the increase of nutrient concentration in the aquatic systems due to superficial drainage. Besides, the increment of precipitations in South America connected to the global climate change could intensify these anthropic impacts due to the changes in the runoff pattern and a greater discharge of water in the streams and rivers. The pampean streams are singular environments with high natural nutrient concentrations which could be increased even more if the predictions of global climate change for the area are met. In this context, the effect of experimental nutrient addition on macroinvertebrates in a lowland stream is studied. Samplings were carried out from March 2007 to February 2009 in two reaches (fertilized and unfertilized), upstream and downstream from the input of nutrients. The addition of nutrients caused an increase in the phosphorus concentration in the fertilized reach which was not observed for nitrogen concentration. From all macroinvertebrates studied only two taxa had significant differences in their abundance after fertilization: Corbicula fluminea and Ostracoda. Our results reveal that the disturbance caused by the increase of nutrients on the benthic community depends on basal nutrients concentration. The weak response of macroinvertebrates to fertilization in the pampean streams could be due to their tolerance to high concentrations of nutrients in relation to their evolutionary history in streams naturally enriched with nutrients. Further research concerning the thresholds of nutrients affecting macroinvertebrates and about the adaptive advantages of taxa in naturally eutrophic environments is still needed. This information will allow for a better understanding of the processes of nutrient cycling and for the construction of restoration measures in natural eutrophic ecosystems.
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This paper presents an outline of rationale and theory of the MuSIASEM scheme (Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism). First, three points of the rationale behind our MuSIASEM scheme are discussed: (i) endosomatic and exosomatic metabolism in relation to Georgescu-Roegen’s flow-fund scheme; (2) the bioeconomic analogy of hypercycle and dissipative parts in ecosystems; (3) the dramatic reallocation of human time and land use patterns in various sectors of modern economy. Next, a flow-fund representation of the MUSIASEM scheme on three levels (the whole national level, the paid work sectors level, and the agricultural sector level) is illustrated to look at the structure of the human economy in relation to two primary factors: (i) human time - a fund; and (ii) exosomatic energy - a flow. The three levels representation uses extensive and intensive variables simultaneously. Key conceptual tools of the MuSIASEM scheme - mosaic effects and impredicative loop analysis - are explained using the three level flow-fund representation. Finally, we claim that the MuSIASEM scheme can be seen as a multi-purpose grammar useful to deal with sustainability issues.
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Environmental research in earth sciences is focused on the geosphere, i.e. (1) waters and sediments of rivers, lakes and oceans, and (2) soils and underlying shallow rock formations,both water-unsaturated and -saturated. The subsurface is studied down to greater depths at sites where waste repositories or tunnels are planned and mining activities exist. In recent years, earth scientists have become more and more involved in pollution problems related to their classical field of interest, e.g. groundwater, ore deposits, or petroleum and non-metal natural deposits (gravel, clay, cement precursors). Major pollutants include chemical substances, radioactive isotopes and microorganisms. Mechanisms which govern the transport of pollutants are of physical, chemical (dissolution, precipitation, adsorption), or microbiological (transformation) nature. Land-use planning must reflect a sustainable development and sound scientific criteria. Today's environmental pollution requires working teams with an interdisciplinary background in earth sciences, hydrology, chemistry, biology, physics as well as engineering. This symposium brought together for the first time in Switzerland earth and soil scientists, physicists and chemists, to present and discuss environmental issues concerning the geosphere.
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Report for the scientific sojourn carried out at the Department of Freshwater Ecology, National Environmetal Research Institute, Denmark, from 2006 to 2008. The main objective of the project was to reconstruct photosynthetic organism community composition using pigmentbased methods and to study their response to natural (e.g. climate) or anthropogenic (e.g. eutrophication) perturbations that took place in the system over time. We performed a study in different locations and at different temporal scales. We analysed the pigment composition in a short sediment record (46 cm sediment depth) of a volcanic lake (Lake Furnas) in the Azores Archipelago (Portugal). The lake has been affected during the last century by successive fish introductions. The specific objective was to reconstruct the lake’s trophic state history and to assess the role of land-use, climate and fish introductions in structuring the lake community. Results obtained suggested that whereas trophic cascade and changes in nutrient concentrations have some clear effects on algal and microbial assemblages, interpreting the effects of changes in climate are not straightforward. This is probably related with the rather constant precipitation in the Azores Islands during the studied period. We also analysed the pigment composition in a long sediment record (1800 cm sediment depth) of Lake Aborre (Denmark) covering ca. 8kyr of lake history. The specific objective was to describe changes in lake primary production and lake trophic state over the Holocene and to determine the photosynthetic organisms involved. Results suggested that external forcing (i.e. land use changes) was responsible of erosion and nutrient run off to the lake that contributed to the reported changes in lake primary production along most of the Holocene.
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The Agglomeration Bonus (AB) is a mechanism to induce adjacent landowners to spatially coordinate their land use for the delivery of ecosystem services from farmland. This paper uses laboratory experiments to explore the performance of the AB in achieving the socially optimal land management configuration in a local network environment where the information available to subjects varies. The AB poses a coordination problem between two Nash equilibria: a Pareto dominant and a risk dominant equilibrium. The experiments indicate that if subjects are informed about both their direct and indirect neighbors’ actions, they are more likely to coordinate on the Pareto dominant equilibrium relative to the case where subjects have information about their direct neighbors’ action only. However, the extra information can only delay – and not prevent – the transition to the socially inferior risk dominant Nash equilibrium. In the long run, the AB mechanism may only be partially effective in enhancing delivery of ecosystem services on farming landscapes featuring local networks.
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This document presents an integrated analysis of the performance of Catalonia based on an analysis of how the energy consumption (measured at the societal level for the Catalan Society) is used within both the productive sectors of the economy and the household, to generate added value, jobs, and to guarantee a given level of material standard of living to the population. The trends found in Catalonia are compared to the trends of other European Countries to contextualize the performance of Catalonia with respect to other societies that have followed different paths of economic development. The first part of the document consists of the Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) approach that has been used to provide this integrated analysis of Catalan Society across different scales (starting from an analysis of the specific sectors of the Catalan economy as an Autonomous Community and scaling up to an intra-regional (European Union 14) comparison) and across different dimensions of analyses of energy consumption coupled with added value generation. Within the scope of this study, we observe the various trajectories of changes in the metabolic pattern for Catalonia and the EU14 countries in the Paid Work Sectors composed of namely, the Agricultural Sector, the Productive Sector and the Services and Government Sector also in comparison with the changes in the household sector. The flow intensities of the exosomatic energy and the added value generated for each specific sector are defined per hour of human activity, thus characterized as exosomatic energy (MJ/hour) (or Exosomatic Metabolic Rate) and added value (€/hour) (Economic Labour Productivity) across multiple levels. Within the second part of the document, the possible usage of the MuSIASEM approach to land use analyses (using a multi-level matrix of categories of land use) has been conducted.