971 resultados para Land cover classification
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Carbon and nitrogen loading to streams and rivers contributes to eutrophication as well as greenhouse gas (GHG) production in streams, rivers and estuaries. My dissertation consists of three research chapters, which examine interactions and potential trade-offs between water quality and greenhouse gas production in urban streams of the Chesapeake Bay watershed. My first research project focused on drivers of carbon export and quality in an urbanized river. I found that watershed carbon sources (soils and leaves) contributed more than in-stream production to overall carbon export, but that periods of high in-stream productivity were important over seasonal and daily timescales. My second research chapter examined the influence of urban storm-water and sanitary infrastructure on dissolved and gaseous carbon and nitrogen concentrations in headwater streams. Gases (CO2, CH4, and N2O) were consistently super-saturated throughout the course of a year. N2O concentrations in streams draining septic systems were within the high range of previously published values. Total dissolved nitrogen concentration was positively correlated with CO2 and N2O and negatively correlated with CH4. My third research chapter examined a long-term (15-year) record of GHG emissions from soils in rural forests, urban forest, and urban lawns in Baltimore, MD. CO2, CH4, and N2O emissions showed positive correlations with temperature at each site. Lawns were a net source of CH4 + N2O, whereas forests were net sinks. Gross CO2 fluxes were also highest in lawns, in part due to elevated growing-season temperatures. While land cover influences GHG emissions from soils, the overall role of land cover on this flux is very small (< 0.5%) compared with gases released from anthropogenic sources, according to a recent GHG budget of the Baltimore metropolitan area, where this study took place.
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Tropical forests have decreased drastically especially in the Peruvian Amazon. In Peru deforestation is caused especially by migrant people; building of houses and infrastructure, clearing land for agricultural purposes and illegal logging and mining. Deforestation results in hindering ecosystem vitality, boosting climate change and decreasing livelihood possibilities. As a counterpoint to cutting down trees there is reforestation, which refers to re-establishment of forest cover. Deforestation and reforestation can be analysed in the light of Forest Transition theory. According to it, due to economic growth, the amount forest cover first diminishes but then starts to increase as the economy in general strengthens. Thus, the research framework is set to this theory. In this study the focus is on analysing socioeconomically sustainable reforestation possibilities in the community of Tingana, Peru. It is situated in a municipal conservation area around which deforestation has been heavy. Land cover change is analysed from LandsatTM satellite images covering a 15 year time period, 1995–2010, in the surroundings of the study area. Semi-structured interviews have been done with a sample size of 25 people and shed light on the perspectives on forests, reforestation and economical activities. The synthesis created from the two methods gives information about the possibilities to enforce reforestation in Tingana and the phase of forest transition in the area. The results show that forest cover has decreased around the surroundings of Tingana leaving the conservation area isolated from larger forest areas. Knowing that forest cover has also decreased inside the conservation area due to agricultural expansion it is certain that fragmentation harms biodiversity causing changes in local climate, which can have knock-on effects for farming and local livelihoods. Therefore reforestation is welcomed when it ensures both conservation and financial benefits and when carried out on locals’ terms. Regarding conservation and incomes the best option would be to plant native timber species together with fruit production species to create agroforestry systems. Economically the community should aim towards an economy that relies on ecotourism as it already practiced in the area. Reforestation could increase ecotourism, which then could in turn increase reforestation via revenues. Regarding forest transition it is likely that forest re-establishment will occur if reforestation along with ecotourism is implemented on long time scale.
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O fogo é um processo frequente nas paisagens do norte de Portugal. Estudos anteriores mostraram que os bosques de azinheira (Quercus rotundifolia) persistem após a passagem do fogo e ajudam a diminuir a sua intensidade e taxa de propagação. Os principais objetivos deste estudo foram compreender e modelar o efeito dos bosques de azinheira no comportamento do fogo ao nível da paisagem da bacia superior do rio Sabor, localizado no nordeste de Portugal. O impacto dos bosques de azinheira no comportamento do fogo foi testado em termos de área e configuração de acordo com cenários que simulam a possível distribuição destas unidades de vegetação na paisagem, considerando uma percentagem de ocupação da azinheira de 2.2% (Low), 18.1% (Moderate), 26.0% (High), e 39.8% (Rivers). Estes cenários tiveram como principal objetivo testar 1) o papel dos bosques de azinheira no comportamento do fogo e 2) de que forma a configuração das manchas de azinheira podem ajudar a diminuir a intensidade da linha de fogo e área ardida. Na modelação do comportamento do fogo foi usado o modelo FlamMap para simular a intensidade de linha do fogo e taxa de propagação do fogo com base em modelos de combustível associados a cada ocupação e uso do solo presente na área de estudo, e também com base em fatores topográficos (altitude, declive e orientação da encosta) e climáticos (humidade e velocidade do vento). Foram ainda usados dois modelos de combustível para a ocupação de azinheira (áreas interiores e de bordadura), desenvolvidos com base em dados reais obtidos na região. Usou-se o software FRAGSATS para a análise dos padrões espaciais das classes de intensidade de linha do fogo, usando-se as métricas Class Area (CA), Number of Patches (NP) e Large Patches Index (LPI). Os resultados obtidos indicaram que a intensidade da linha de fogo e a taxa de propagação do fogo variou entre cenários e entre modelos de combustível para o azinhal. A intensidade média da linha de fogo e a taxa média de propagação do fogo decresceu à medida que a percentagem de área de bosques de azinheira aumentou na paisagem. Também foi observado que as métricas CA, NP e LPI variaram entre cenários e modelos de combustível para o azinhal, decrescendo quando a percentagem de área de bosques de azinheira aumentou. Este estudo permitiu concluir que a variação da percentagem de ocupação e configuração espacial dos bosques de azinheira influenciam o comportamento do fogo, reduzindo, em termos médios, a intensidade da linha de fogo e a taxa de propagação, sugerindo que os bosques de azinhal podem ser usados como medidas silvícolas preventivas para diminuir o risco de incêndio nesta região.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, Programa de Pós-Graduação em Tecnologia Ambiental e Recursos Hídricos, 2015.
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Reports of triatomine infestation in urban areas have increased. We analysed the spatial distribution of infestation by triatomines in the urban area of Diamantina, in the state of Minas Gerais, Brazil. Triatomines were obtained by community-based entomological surveillance. Spatial patterns of infestation were analysed by Ripley’s K function and Kernel density estimator. Normalised difference vegetation index (NDVI) and land cover derived from satellite imagery were compared between infested and uninfested areas. A total of 140 adults of four species were captured (100 Triatoma vitticeps, 25 Panstrongylus geniculatus, 8 Panstrongylus megistus, and 7 Triatoma arthurneivai specimens). In total, 87.9% were captured within domiciles. Infection by trypanosomes was observed in 19.6% of 107 examined insects. The spatial distributions of T. vitticeps, P. geniculatus, T. arthurneivai, and trypanosome-positive triatomines were clustered, occurring mainly in peripheral areas. NDVI values were statistically higher in areas infested by T. vitticeps and P. geniculatus. Buildings infested by these species were located closer to open fields, whereas infestations of P. megistus and T. arthurneivai were closer to bare soil. Human occupation and modification of natural areas may be involved in triatomine invasion, exposing the population to these vectors.
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Overrecentdecades,remotesensinghasemergedasaneffectivetoolforimprov- ing agriculture productivity. In particular, many works have dealt with the problem of identifying characteristics or phenomena of crops and orchards on different scales using remote sensed images. Since the natural processes are scale dependent and most of them are hierarchically structured, the determination of optimal study scales is mandatory in understanding these processes and their interactions. The concept of multi-scale/multi- resolution inherent to OBIA methodologies allows the scale problem to be dealt with. But for that multi-scale and hierarchical segmentation algorithms are required. The question that remains unsolved is to determine the suitable scale segmentation that allows different objects and phenomena to be characterized in a single image. In this work, an adaptation of the Simple Linear Iterative Clustering (SLIC) algorithm to perform a multi-scale hierarchi- cal segmentation of satellite images is proposed. The selection of the optimal multi-scale segmentation for different regions of the image is carried out by evaluating the intra- variability and inter-heterogeneity of the regions obtained on each scale with respect to the parent-regions defined by the coarsest scale. To achieve this goal, an objective function, that combines weighted variance and the global Moran index, has been used. Two different kinds of experiment have been carried out, generating the number of regions on each scale through linear and dyadic approaches. This methodology has allowed, on the one hand, the detection of objects on different scales and, on the other hand, to represent them all in a sin- gle image. Altogether, the procedure provides the user with a better comprehension of the land cover, the objects on it and the phenomena occurring.
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Le réchauffement climatique affecte fortement les régions nordiques du Canada où le dégel du pergélisol discontinu à sa limite sud est accompagné du mouvement de la limite des arbres vers le nord en zone de pergélisol continu. Ces altérations faites aux paysages de la Taïga des Plaines sont le point de départ de plusieurs rétroactions puisque les changements apportés aux caractéristiques de la surface (au niveau de l’albédo, l’humidité du sol et la rugosité de la surface) vont à leur tour entraîner des modifications biophysiques et éventuellement influencer l’augmentation ou la diminution subséquente des températures et de l’humidité de l’air. Seulement, il y a un nombre important de facteurs d’influence qu’il est difficile de projeter toutes les boucles rétroactives qui surviendront avec les présents changements climatiques en régions nordiques. Dans le but de caractériser les échanges d’eau et d’énergie entre la surface et l’atmosphère de trois sites des Territoires du Nord-Ouest subissant les conséquences de l’augmentation des températures de l’air, la méthode micro-météorologique de covariance des turbulences fut utilisée en 2013 aux sites de Scotty Creek (forêt boréale et tourbière nordique en zone de pergélisol sporadique-discontinu), de Havikpak Creek (forêt boréale nordique en zone de pergélisol continu) et de Trail Valley Creek (toundra arctique en zone de pergélisol continu). En identifiant les procédés biotiques et abiotiques (ex. intensité lumineuse, disponibilité en eau, etc.) d’évapotranspiration aux trois sites, les contrôles par l’eau et l’énergie furent caractérisés et permirent ainsi de projeter une augmentation de la limitation en eau, mais surtout en énergie du site de Trail Valley Creek. La répartition de l’énergie projetée est semblable à celle de Havikpak Creek, avec une augmentation de la proportion du flux de chaleur sensible au détriment de celui latent suite aux modifications des caractéristiques de la surface (albédo, rugosité et humidité du sol). L’augmentation relative du flux d’énergie sensible laisse présager une boucle rétroactive positive de l’augmentation des températures de l’air à ce site. Ensuite, en comparant des données modelées de la hauteur de la couche limite planétaire et des données provenant de profils atmosphériques d’Environnement Canada entre les trois sites, les changements de hauteur de cette couche atmosphérique furent aussi projetés. Trail Valley Creek pourrait connaître une hausse de la hauteur de sa couche limite planétaire avec le temps alors que Scotty Creek connaîtrait une diminution de celle-ci. Ces changements au niveau des couches atmosphériques liés à la répartition des flux d’énergie dans les écosystèmes se répercuteraient alors sur le climat régional de façon difficile à déterminer pour l’instant. Les changements apportés désignent une boucle rétroactive positive des températures de l’air à Trail Valley Creek et l’inverse à Scotty Creek. Les deux axes d’analyse arrivent donc aux mêmes conclusions et soulignent aussi l’importance de l’influence mutuelle entre le climat et les caractéristiques spécifiques des écosystèmes à la surface.
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Le réchauffement climatique affecte fortement les régions nordiques du Canada où le dégel du pergélisol discontinu à sa limite sud est accompagné du mouvement de la limite des arbres vers le nord en zone de pergélisol continu. Ces altérations faites aux paysages de la Taïga des Plaines sont le point de départ de plusieurs rétroactions puisque les changements apportés aux caractéristiques de la surface (au niveau de l’albédo, l’humidité du sol et la rugosité de la surface) vont à leur tour entraîner des modifications biophysiques et éventuellement influencer l’augmentation ou la diminution subséquente des températures et de l’humidité de l’air. Seulement, il y a un nombre important de facteurs d’influence qu’il est difficile de projeter toutes les boucles rétroactives qui surviendront avec les présents changements climatiques en régions nordiques. Dans le but de caractériser les échanges d’eau et d’énergie entre la surface et l’atmosphère de trois sites des Territoires du Nord-Ouest subissant les conséquences de l’augmentation des températures de l’air, la méthode micro-météorologique de covariance des turbulences fut utilisée en 2013 aux sites de Scotty Creek (forêt boréale et tourbière nordique en zone de pergélisol sporadique-discontinu), de Havikpak Creek (forêt boréale nordique en zone de pergélisol continu) et de Trail Valley Creek (toundra arctique en zone de pergélisol continu). En identifiant les procédés biotiques et abiotiques (ex. intensité lumineuse, disponibilité en eau, etc.) d’évapotranspiration aux trois sites, les contrôles par l’eau et l’énergie furent caractérisés et permirent ainsi de projeter une augmentation de la limitation en eau, mais surtout en énergie du site de Trail Valley Creek. La répartition de l’énergie projetée est semblable à celle de Havikpak Creek, avec une augmentation de la proportion du flux de chaleur sensible au détriment de celui latent suite aux modifications des caractéristiques de la surface (albédo, rugosité et humidité du sol). L’augmentation relative du flux d’énergie sensible laisse présager une boucle rétroactive positive de l’augmentation des températures de l’air à ce site. Ensuite, en comparant des données modelées de la hauteur de la couche limite planétaire et des données provenant de profils atmosphériques d’Environnement Canada entre les trois sites, les changements de hauteur de cette couche atmosphérique furent aussi projetés. Trail Valley Creek pourrait connaître une hausse de la hauteur de sa couche limite planétaire avec le temps alors que Scotty Creek connaîtrait une diminution de celle-ci. Ces changements au niveau des couches atmosphériques liés à la répartition des flux d’énergie dans les écosystèmes se répercuteraient alors sur le climat régional de façon difficile à déterminer pour l’instant. Les changements apportés désignent une boucle rétroactive positive des températures de l’air à Trail Valley Creek et l’inverse à Scotty Creek. Les deux axes d’analyse arrivent donc aux mêmes conclusions et soulignent aussi l’importance de l’influence mutuelle entre le climat et les caractéristiques spécifiques des écosystèmes à la surface.
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Introdução Caracterização da área de estudo Materiais e métodos O modelo SWAT Dados de chuva, vazão e produção de sedimentos Tipos de solos e determinação dos parâmetros do SWAT Análises Estatísticas Cenários de Uso do Solo Resultados e discussões Estimativa da Vazão Estimativa da produção de sedimentos Modelagem Hidrossedimentológica em Diferentes Cenários Conclusões Referências bibliográficas RESUMO – A erosão dos solos é um dos mais graves problemas ambientais em todo o mundo, principalmente em regiões semiáridas que sofrem com a variabilidade espaço-temporal da precipitação. Este artigo analisou os processos hidrossedimentológicos na Bacia do Rio Cobres, localizada na porção semiárida de Portugal, utilizando o modelo SWAT. Neste estudo foram utilizados dados diários de precipitação, temperatura, umidade do ar, vazão e produção de sedimentos, para o período de 1960 a 2000, mapas digitais de elevação do terreno com resolução espacial de 90 m, uso e ocupação do solo e tipos de solo da bacia. Os resultados demonstraram a eficácia do modelo na calibração da vazão, com Coeficiente de Determinação (R²) = 0,81 e Coeficiente de Nash-Sutcliffe (NS) = 0,63, e também para produção de sedimentos com R² = 0,62 e NS = 0,47. O Cenário 3 (Mata) apresentou o maior decréscimo na vazão média, em relação aos Cenários 1 (Real) e 2 (Pastagem). Conclui-se que o modelo SWAT acoplado ao SIG é uma ferramenta poderosa na análise espaço-temporal do comportamento dos processos hidrossedimentológicos. Palavas-chave: SIG, modelo hidrossedimentológico, erosão ABSTRACT – Effects of Scenarios of Land Use on Runoff and Sediment Yield for Cobres River Basin, Portugal. Soil erosion is a major environmental problem worldwide, mainly in semiarid regions that suffer with rainfall spatial and temporal variability. Thus, this paper analysed the runoff-erosion process at the Cobres River Basin, located in semiarid portion of Portugal, using the SWAT model. In this paper, rainfall, temperature and humidity data from 1960 to 2000, and digital maps of land cover, terrain digital elevation model with spatial resolution of 90 m, soil types were used. The results showed the effectiveness of the model for the runoff calibration, with R² = 0.81 and NS = 0.63, and also for sediment yield with R² = 0.62 and NS = 0.47. Scenario 1 (Forest) had the highest decrease in average streamflow, in relation to the Scenarios 1 (Real) and 2 (Pasture) scenarios. It is concluded that the SWAT model coupled to GIS is a powerful tool in the analysis of temporal and spatial behaviour of runoff-erosion processes.
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Context Understanding connectivity patterns in relation to habitat fragmentation is essential to landscape management. However, connectivity is often judged from expert opinion or species occurrence patterns, with very few studies considering the actual movements of individuals. Path selection functions provide a promising tool to infer functional connectivity from animal movement data, but its practical application remains scanty. Objectives We aimed to describe functional connectivity patterns in a forest carnivore using path-level analysis, and to explore how connectivity is affected by land cover patterns and road networks. Methods We radiotracked 22 common genets in a mixed forest-agricultural landscape of southern Portugal. We developed path selection functions discriminating between observed and random paths in relation to landscape variables. These functions were used together with land cover information to map conductance surfaces. Results Genets moved preferentially within forest patches and close to riparian habitats. Functional connectivity declined with increasing road density, but increased with the proximity of culverts, viaducts and bridges. Functional connectivity was favoured by large forest patches, and by the presence of riparian areas providing corridors within open agricultural land. Roads reduced connectivity by dissecting forest patches, but had less effect on riparian corridors due to the presence of crossing structures. Conclusions Genet movements were jointly affected by the spatial distribution of suitable habitats, and the presence of a road network dissecting such habitats and creating obstacles in areas otherwise permeable to animal movement. Overall, the study showed the value of path-level analysis to assess functional connectivity patterns in human-modified landscapes.
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Aim To examine the distributional patterns of vertebrates (including birds, bats, carnivores and lagomorphs) along landscape composition and configuration gradients to better understand the effects of landscape modification on occurrence patterns at both species and community level. Location The region of Alentejo, a forest-dominated area of southern Portugal. Methods The study area was framed using 1647 hexagonal plots, each of 259 ha in size. Composition and configuration gradients were obtained for each plot by integrating the proportions of the main land cover types and their configuration patterns using multivariate analyses. Species-specific vertebrate responses were investigated using data from 75 plots in which carnivores, bats and lagomorphs were sampled, and from 135 plots in the case of birds. Community- level responses were investigated through changes in species richness and beta-diversity in 57 plots where all vertebrate groups were simultaneously sampled. At the species-level, an information-theoretic approach was used to determine the effects of landscape gradients on species’ responses. At the community level, Mantel tests were used to determine between-plot differences in species composition using the Sørensen dissimilarity index. Results We found that the occurrence patterns of most vertebrate species were best predicted by composition-related gradients, although configuration gradients were also frequently included in species-specific occurrence models. We also found a weak correlation between species richness and most landscape gradients suggesting a turnover in the identity of species, something that was corroborated by the stronger correlation between environmental gradients and beta-diversity measures. The amount of forest cover and landscape complexity (estimated as the heterogeneity in the size and number of land cover types) were the main composition and configuration gradients determining vertebrate responses at both species and community level. Main conclusions Our work contributes to a more refined understanding of the mechanisms underlying species distributional patterns in real-world human-modified landscapes. By uncovering generalities of species with multiple ecological requirements and by describing the entire landscape mosaic through landscape gradients, we also suggest that our work greatly helps to fill the gap between existing conceptual landscape models aimed to understand species distributional patterns in human-modified landscapes.
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A cartografia temática surge como um aliado indispensável ao estudo e conhecimento do estado da paisagem e dos ecossistemas terrestres. Angola é um país com uma enorme lacuna em termos de informação cartográfica para suporte a diversas actividades desenvolvidas em várias áreas. É por isso necessária informação sobre a superfície terrestre que registe as alterações temporais ocorridas nos ecossistemas e identifique os factores que estão na sua origem de forma a implementar medidas que permitam uma gestão mais sustentável do seu enorme território. O presente estudo foi realizado no sector Sudoeste de Angola, abrangendo os municípios do Lubango, Humpata e Chibia, com uma área aproximada de 9600 km2. Os objectivos foram: a) cartografar o coberto do solo e monitorizar as alterações ocorridas na área de estudo no período 1990-2010, b) analisar e interpretar as alterações da estrutura da paisagem nos últimos 20 anos usando cartografia de ocupação do solo, produzida recorrendo a imagens de satélite, e métricas da paisagem, e c) quantificar e examinar a relação entre a fragmentação da paisagem e os factores geradores. A metodologia utilizada no estudo é composta por duas partes, sendo a primeira dedicada às operações de processamento e interpretação de imagens de satélite Landsat e, a segunda dedicada à produção de novas métricas de fragmentação da paisagem com recurso à ferramenta SIG utilizando operações de álgebra de mapas. O comportamento da fragmentação é analisado, à luz do efeito dos fatores ambientais e socioeconómicas ao nível da região. Os resultados obtidos, através da aplicação de técnicas de deteção remota e usando imagens Landsat TM e ETM+, permitiram a elaboração de mapas de coberto do solo, onde se distinguiram 8 classes temáticas e espectralmente diferentes. Verificou-se em termos globais que aproximadamente 38% da área sofreu algum tipo de alteração no período estudado, sendo as classes de miombo e áreas cultivadas as que mais alterações sofreram. A fragmentação da paisagem foi avaliada através da implementação de novas métricas, mostrando os resultados, que no período 1990-2000, a fragmentação foi superior à que se verificou entre 2000-2010. A nível espacial, a dinâmica de fragmentação foi mais acentuada, entre 1990-2000, na Humpata e, entre 2000-2010, no Lubango; ANALYSIS OF LANDSCAPE AND LAND USE LAND COVER CHANGE IN LUBANGO AND SURROUNDINGS ABSTRACT: Thematic cartography shows up as an essential ally in the study and knowledge of the state of landscapes and terrestrial ecosystems. Angola is a country with an enormous lack of cartographic information to support the several activities carried out in a variety of areas. This is the reason information on the earth’s surface is necessary, registering alterations which occur over time in ecosystems and identifying the associated factors in its origin, so as to implement metrics that allow a more sustainable management of its enormous territory. This study was carried out in the Southeast of Angola in the Lubango, Humpata and Chibia Municipalities, with an area of approximately 9600 km2. Our objectives were the following: a) land cover mapping and land cover changes monitoring over the period 1990 to 2010 using Landsat images, b) to analyze and interpret landscape structures changes using land cover maps, and landscapes metrics, and c) to quantify and to examine the relationship between landscape fragmentation and its drivers. The methodology developed in the study has two parts, the first includes Landsat satellite images processing and interpretation and, the second the production of new landscape fragmentation metrics with support to a GIS tool and algebraic mapping operations. The fragmentation behavior is analyzed, taking into account the effect of environmental and socioeconomic factors at a regional level. The results allowed obtaining land cover maps, in which 8 spectrally different thematic classes were distinguished. It was observed that 38% of the area suffered some type of alteration in the studied period, with higher changes observed in the classes of miombo and agriculture. Landscapes fragmentation results, evaluated through the implementation of new metrics, show that, values are greater in the period 1990-2000 than in 2000-2010. At municipality level, fragmentation dynamics were more accentuated in Humpata between 1990 -2000 and in Lubango between 2000 -2010.
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The current study approaches the sugarcane culture expansion in Southwestern Goiás, especially in Mineiros, Quirinópolis and Rio Verde counties, which represent different times and responses to this process. The current logistics structure and future prospects for sugarcane and its derivatives transportation are studied at national level with emphasis to the aforementioned micro-region. Maps showing land use and land cover in three different years were generated from Landsat TM-5 satellite images and they were used to analyze the dynamics of changes in land use and in land cover. The region is marked by strong and rapid growth in the agricultural sector and its sugar-energy industry has been expanding in recent years, although with different aspects among its counties. Since it is a promising region in this sector, due to the favorable soil and weather conditions to the crop, the region requires more investment and planning in logistics to ensure production flow and to make it stronger within domestic and foreign markets.
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Se presenta un análisis de los posibles factores explicativos del crecimiento urbano en la Comunidad de Madrid durante el período 1990-2000, incluyendo la zonificación de la región en relación a las coronas metropolitanas en torno a la ciudad de Madrid. Se analizan las categorías estructura urbana laxa, urbanizaciones exentas y zonas industriales y comerciales establecidas en la cartografía de usos del suelo Corine Land Cover. Como factores explicativos del cambio se tomaron variables socioeconómicas, biofísicas, de planificación legal, políticas y de proximidad/accesibilidad, medidas en cada píxel del territorio. El análisis de la relación entre las variables explicativas y el crecimiento urbano se llevó a cabo a través de la regresión logística. Los resultados obtenidos del ajuste de los modelos mostró la relevancia de algunas variables en la explicación de la localización del crecimiento de las categorías urbanas analizadas.Palabras Clave: crecimiento urbano, variables explicativas, regresión logística, Corine Land Cover,MadridABSTRACTThis paper presents an analysis of the possible explanatory factors of urban growth in Madrid, Spain during the period 1990-2000, including the zoning of the region in relation to the metropolitan area around the city. Specifically, two categories were analyzed: residential discontinuous urban andresidential discontinuous sparse urban, and commercial and industrial of the Corine Land Cover. Previous analysis of Corine Land Cover land use change identified these categories as having the largest growth during the study period. Socio-economic, biophysical, legal planning, policies andproximity/accessibility variables were taken into account as explanatory factors of urban growth, at pixel level. Logistic regression was used to analyze the relationship between explanatory variables and urban growth. The results obtained from the model adjustments showed the relevance of somevariables in explaining the location of urban growth in the categories analyzed.Keyword: GIS, urban growth, explanatory factors, logistic regression, Corine Land Cover, Madrid,Spain
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Vulnerability and sustainability studies of an area help to assess both its level of exposure and capacity to support possible environmental impacts, and it is of primordial importance for proposals of the Legislation on Zoning, Allotment, Land Use/land cover, aiming to stimulate those areas indicated for urban growth, to discourage growth of overcrowded areas, to detect sections with restrictive use, as well as districts for permanent protection. This paper aims to analyze the vulnerability in the Maranhão Ilha, using GIS techniques, geospatial inference intersected with relevant social-environmental indicators.Estudos de vulnerabilidade e de sustentabilidade de uma área ajudam a avaliar o seu grau de exposição e sua capacidade de suporte a possíveis impactos ambientais, sendo fundamental para propostas de Lei de Zoneamento, Parcelamento, Uso e Ocupação do Solo, tendo por finalidade orientar as áreas onde deverá haver estímulo para o crescimento urbano; contenção da malha urbana; detecção de locais com possibilidade de uso restritivo, bem como locais de proteção permanente. Este trabalho propõe analisar o índice de vulnerabilidade a perda de solo da Ilha do Maranhão com base na metodologia proposta por (CREPANI, et al. 2001) e em técnicas de inferência espacial com apoio na AHP (Análise Hierárquica de Processo).