Since the early 1800's, many studies have recognized increased heat in urban areas, known as the urban heat island (UHI) effect, as one of the results of human modification to the natural landscape. UHI is related to differences in land surface temperature (LST) between rural areas and urban areas where factors of the built environment such as the thermodynamic capacities of materials, structural geometry, and heat generating activities cause increased storage and re-radiation of heat to the atmosphere. This thesis examines the correlation between factors of urbanization and differences in land surface temperature (LST) in the subtropical climate of Pinellas County, Florida using remote sensing techniques. It describes the spatial pattern of LST, analyzes its relationship to factors of urbanization relative to NDVI, percentage of impervious surface, and land use land cover in the study area. It also assesses the effectiveness of remote sensing as an efficient method of identifying LST patterns at the local and neighborhood level for mitigation strategies. Landsat TM thermal band imagery for three dates; April 1986, 2001 and 2009 was processed using Qin's mono-window algorithm (MWA) technique to derive LST levels. This data was compared to in-situ readings, then normalized and statistically analyzed for correlation with vegetation ratio (NDVI) and imperviousness percentages derived using linear spectral mixing/unmixing, and also with land use/land cover classification. The resulting LST spatial pattern is a gradient across the peninsular landscape, from cooler water and wetland areas to a generally warmer interior, interspersed with micro-urban heat islands (MUHIs), corresponding to urban structures and "cool-islands" of parkland and lakes. Correspondence between LST pattern and urban structures and land use demonstrates the suitability of medium resolution remote sensing data and techniques for identifying micro-urban heat islands (MUHIs) for possible mitigation. Mitigation could include relatively low-cost measures like replacement of inefficient asphalt roofs with more reflective and emissive "cool roofs," placement of "street trees" to enhance shade, and replacement of impervious pavements by permeable surfaces. The thesis concludes that Landsat TM imagery processed with the MWA provides an efficient, relatively low-cost method for locating MUHIs. Satellite remote sensing, combined with aerial photography can facilitate neighborhood level analysis for the implementation of low-cost mitigation techniques. Previous studies have demonstrated that these are successful ways to mitigate the UHI effect at the micro-scale level; lowering urban heat and saving energy, and also facilitating the reintegration of natural elements into the urban environment.

Thesis (M. En.)--Miami University, Institute of Environmental Sciences, 2008. / Title from first page of PDF document. Includes bibliographical references (p. 16-21-Xx).

Thesis (MA (Geography and Environmental Studies))--University of Stellenbosch, 2005. / Salinisation is a major environmental hazard that reduces agricultural yields and degrades arable land. Two main categories of salinisation are: primary and secondary soil salinisation. While primary soil salinisation is caused by natural processes, secondary soil salinisation is caused by human factors. Incorrect irrigation practices are the major contributor to secondary soil salinisation. Because of low costs and less time that is associated with the use of remote sensing techniques, remote sensing data is used in this study to identify and map salinised irrigated land between Upington and Keimoes, Northern Cape Province, in South Africa. The aim of this study is to evaluate the potential of digital aerial imagery in identifying salinised cultivated land. Two methods were used to realize this aim. The first method involved visually identifying salinised areas on NIR, and NDVI images and then digitizing them onscreen. In the second method, digital RGB mosaicked, stacked, and NDVI images were subjected to unsupervised image classification to identify salinised land. Soil samples randomly selected and analyzed for salinity were used to validate the results obtained from the analysis of aerial photographs. Both techniques had difficulties in identifying salinised land because of their inability to differentiate salt induced stress from other forms of stress. Visual image analysis was relatively successful in identifying salinised land than unsupervised image classification. Visual image analysis correctly identified about 55% of salinised land while only about 25% was identified by unsupervised classification. The two techniques predict that an average of about 10% of irrigated land is affected by salinisation in the study area. This study found that although visual analysis was time consuming and cannot differentiate salt induced stress from other forms; it is fairly possible to identify areas of crop stress using digital aerial imagery. Unsupervised classification was not successful in identifying areas of crop stress.

The remnants of vegetation native to the Atlantic Forest account for about 22% of their original cover and are in different stages of regeneration. The typologies belonging to the biome and found in the northwest of the state of Rio Grande do Sul are mixed ombrophilous forest and deciduous seasonal forest. Amid the consequences of the current dynamics of land use and occupation caused by man, there is the fragmentation of primary and secondary forests, where an area continues to result in a large number of isolated fragments of different sizes. Among the various environmental services provided by forest ecosystems, the most important is the sequestration and storage of carbon in the form of biomass. Thus, the role of native forests in the removal and stocking of carbon is fundamental, demonstrating the need to develop new methods that estimate forest biomass and carbon by non-destructive methods. The objective of the present work is to estimate and study the dynamics of biomass and forest carbon stock in successional stages of regeneration in the Northwest Region of the State of Rio Grande do Sul. The study area is located in the Northwest of the State of Rio Grande do Sul , Covering two microregions, Três Passos and Frederico Westphalen. For this study two methodologies were developed to estimate the forest biomass stock, both based on remote sensing data. The study in the first methodology was carried out for the dates of 1985, 1994, 2005 and 2014, and covers an area of 9,046.9 km². The classification of forest successions in regeneration stages was a continuation of the work of Rosa (2016), where the size classes: initial (<5 ha), medium (5 - 10 ha), advanced (> 10 ha), later Biomass for them. For the second methodology, images from each year were used from 1985 to 2014, where the NDVI was calculated, and through regression generated for the global model, to obtain the IAF and to estimate the forest biomass. Subsequently, comparing both methodologies were compared among themselves, and compared with values provided by the methodology of the Brazilian Forest Service. For the first study, forest biomass in 2014 in the Northwest Region of the state of Rio Grande do Sul was 80,831 Gg, divided into three stages of initial (659 Gg) regeneration (2,549 Gg) and advanced (77,623 Gg) regeneration. In the study area, there are three protected areas, the Turvo State Park, the Nonoai Indigenous Reserve and the Guarita Indian Reserve, which account for almost 25% of the total stock of the region, and are significant areas in the carbon stock. The carbon estimated by the first methodology was 296 Gg for the initial stage, 1,147 for the medium stage and 34,930 for the advanced stage, totaling 36,373 Gg. For the second methodology, it was possible to observe the great relation between the increase of the LAI as a function of NDVI and the forest biomass in 2014 was 61,156 Gg, where 602 Gg corresponds to the initial regeneration stage, 8,287 Gg for the medium stage and 52,267 Gg for The advanced stage of regeneration. The estimated total carbon for the study area in 2014 according to the second methodology was 27,520 Gg CO2, of which 271 Gg were present in the initial stage, 3,729 Gg in the medium stage and 23,520 Gg in the advanced stage of regeneration. In the comparison of the methodologies developed in this study, a difference of 19,675 Gg was obtained, due mainly to the effects of edges of the studied fragments. Comparing the first and second methodologies developed with that provided by the Brazilian Forest Service, only 10 and 14.30% of the estimated values for forest biomass were obtained. / Os remanescentes de vegetação nativa da Mata Atlântica contabilizam cerca de 22% de sua cobertura original e se encontram em diferentes estágios de regeneração. As tipologias pertencentes ao bioma e que se encontram no noroeste do estado do Rio Grande do Sul são floresta ombrófila mista e floresta estacional decidual. Em meio às consequências da atual dinâmica do uso e ocupação do solo causadas pelo homem, está a fragmentação de florestas primárias e secundárias, onde uma área continua resulta em um grande número de fragmentos isolados e de diferentes tamanhos. Entre os diversos serviços ambientais prestados pelos ecossistemas florestais, se destaca o sequestro e estocagem do carbono na forma de biomassa. Assim é fundamental o papel das florestas nativas na remoção e estoque do carbono, demonstrando a necessidade de desenvolver novos métodos que estimem a biomassa e carbono de florestas por meio de métodos não destrutivos. O objetivo do presente trabalho é estimar e estudar a dinâmica do estoque da biomassa e do carbono florestal em estágios sucessionais de regeneração na Região Noroeste do Estado do Rio Grande do Sul. A área de estudo está localizada no Noroeste do Estado do Rio Grande do Sul, abrangendo duas microrregiões, Três Passos e Frederico Westphalen. Para este estudo foram desenvolvidas duas metodologias para estimar o estoque de biomassa florestal, ambas baseadas em dados de sensoriamento remoto. O estudo na primeira metodologia foi realizado para as datas de 1985, 1994, 2005 e 2014, e abrange área de 9.046,9 km². A classificação das sucessões florestais em estágios de regeneração se deu por continuidade ao trabalho de Rosa (2016), onde as classes de tamanho: inicial (< 5 ha), média (5 – 10 ha), avançada (> 10 ha), depois estimadas a biomassa para elas. Para a segunda metodologia, foram usadas imagens de todos os anos desde 1985 a 2014, onde foi calculado o NDVI, e através de regressão gerada para o modelo global, se obter o IAF e estimar a biomassa florestal. Posteriormente, comparou-se ambas as metodologias foram comparadas entre si, e comparadas com valores fornecidos pela metodologia do Serviço Florestal Brasileiro. Para o primeiro estudo, a biomassa florestal em 2014 na Região Noroeste do estado do Rio Grande do Sul foi de 80.831 Gg, divididos em três estágios de regeneração inicial (659 Gg) médio (2.549 Gg) e avançado (77.623 Gg). Na área de estudo, estão presentes três áreas protegidas, o Parque Estadual do Turvo, a Reserva indígena de Nonoai e a Reserva indígena do Guarita, as quais possuem quase 25% do estoque total da região, e são áreas significativas no estoque de carbono. O carbono estimado pela primeira metodologia foi de 296 Gg para o estágio inicial, 1.147 para o estágio médio e 34.930 para o estágio avançado, totalizando 36.373 Gg. Para a segunda metodologia, foi possível observar a grande relação entre o aumento do IAF em função do NDVI estimando a biomassa florestal em 2014 foi de 61.156 Gg onde 602 Gg correspondem ao estágio de regeneração inicial, 8.287 Gg para o estágio médio e 52.267 Gg para o estágio avançado de regeneração. O total de carbono estimado para a área de estudo em 2014 conforme a segunda metodologia foi de 27.520 Gg CO2 sendo desses 271 Gg presentes no estágio inicial, 3.729 Gg no estágio médio e 23.520 Gg no estágio avançado de regeneração. Na comparação das metodologias desenvolvidas neste estudo, obteve-se uma diferença de 19.675 Gg, devido principalmente aos efeitos de bordas dos fragmentos estudados. Comparando-se a primeira e a segunda metodologias desenvolvidas com a fornecida pelo Serviço Florestal Brasileiro, obteve-se apenas 10 e 14,30% dos valores estimados para a biomassa florestal.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Proper nutrition nitrogen in cotton directly affects obtain high productivity of the crop. Decision making based on the use of sensors is an alternative to increase the efficiency of fertilization with this nutrient, however, the accuracy of the sensors and the vegetative stages most suitable for the realization of the readings are not well defined. In this context the present study had the following objectives: I - Evaluate the effectiveness of an optical sensor to estimate the nutritional status of cotton crop under different N rates; II- Which phenological stages the optical sensor has higher efficiency. III - Establish response curve in the cotton productivity in relation to nitrogen and estimate reference values to use the optical sensor on the prescription variable rate fertilizer. The experiment was conducted in the agricultural year 2012/13 on a Oxisol in the western state of Bahia. The experiment was conducted at three sites and experimental design was a randomized block design with seven treatments and three replications. Treatments consisted of the following N rates: 0, 45, 90, 130, 150, 180 and 220 kg ha-1 applied at 43 days after sowing (DAS) in area 1 and 32 DAS in areas 2 and 3. Readings vegetation index (IV) were carried out in three seasons, corresponding to 63, 75 and 97 DAS in area 1 and 45, 57 and 80 DAS in areas 2 and 3, using the optical sensor N-Sensor ALS® (YARA) . Adjacent stages and the read points IV, samplings to determine dry matter (DM) were taken, and measurement of the absorbed nitrogen and plant height, furthermore, the determination of the yield of cotton was carried out. The sensor reading and the other factors evaluated were subjected to regression analysis by the statistical program Sigma Plot 11. The N fertilizer applied significantly altered the vegetative attributes evaluated. Reading the IV optical sensor showed high correlation with crop nutritional status determined by N does in the three areas evaluated for the different stages of evaluation. Reading the vegetation index obtained by the sensor also showed high correlation with the 8 parameters plant height, DM and N absorbed. The productivity of cotton crop showed a quadratic fit with the N levels in all experiments. The preliminary calibration value suggesting that the critical IV would be equal to 60 for the stage F1 in the middle of the three areas studied. / A nutrição nitrogenada do algodoeiro afeta diretamente a produtividade da cultura. Decisões baseadas no uso de sensores são uma alternativa para aumentar a eficiência da fertilização nitrogenada em diversas culturas. No entanto, para o algodão, a acurácia da estimativa do estado nutricional e dos estádios vegetativos mais adequados para a realização das leituras ainda não estão bem definidos. Nesse contexto, o presente trabalho teve os seguintes objetivos: I - avaliar a eficácia de um sensor óptico na estimativa do estado nutricional da cultura do algodoeiro submetido a diferentes doses de nitrogênio (N); II avaliar em quais estádios fenológicos o sensor óptico possui maior eficiência; III - estabelecer curva de resposta de produtividade no algodoeiro em relação à aplicação de N e IV - estimar valores de referências para utilização do sensor óptico na prescrição de fertilizantes em taxa variada. O experimento foi conduzido no ano agrícola de 2012/13 em um Latossolo Vermelho Amarelo, no oeste do estado da Bahia, sob clima tropical com precipitação anual de 1600 mm ano-1 e temperatura média anual em torno de 21ºC. O experimento foi realizado em três locais, e o delineamento experimental foi em blocos ao acaso, com sete tratamentos e três repetições. Os tratamentos consistiram nas seguintes doses de N: 0, 45, 90, 130, 150, 180 e 220 kg ha-1 aplicadas aos 43 dias após a semeadura (DAS) na área 1 e aos 32 DAS nas áreas 2 e 3. As leituras de índice de vegetação (IV) foram realizadas em três épocas, correspondentes aos 63, 75 e 97 DAS na área 1 e aos 45, 57 e 80 DAS nas áreas 2 e 3, utilizando o sensor óptico N-Sensor ALS® (YARA). Adjacente aos estádios e pontos de leitura de IV, foram realizadas coletas de plantas para determinar a produção de matéria seca (MS) e a quantidade de N absorvido e avaliar a altura de planta e a produtividade do algodoeiro. A leitura do sensor e os demais fatores avaliados foram submetidos à análise de regressão pelo programa estatístico Sigma Plot 11. As doses de N fertilizante 6 aplicadas alteraram significativamente os atributos vegetativos avaliados. A leitura do IV do sensor óptico apresentou elevada correlação com o estado nutricional da cultura determinado pelas doses de N nas três áreas avaliadas para os diferentes estádios de avaliação. A leitura do IV obtida pelo sensor também apresentou elevada correlação com os parâmetros altura de planta, MS e N absorvido. A produtividade da cultura do algodoeiro apresentou um ajuste quadrático com as doses de N nos três experimentos. A calibração preliminar sugere que o valor de IV crítico seria igual a 60 para o estádio F1 na média das três áreas estudadas.

Made available in DSpace on 2014-06-11T19:32:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-11-25Bitstream added on 2014-06-13T20:23:28Z : No. of bitstreams: 1 lourenco_rw_dr_rcla.pdf: 3630116 bytes, checksum: fb0129ce370013b74524f591efbb0d6d (MD5) / O aspecto fundamental do trabalho é mostrar a importância da integração de um Sistema de Informações Geográficas (SIG) com procedimentos geoestatísticos na análise e interpretação de dados distribuídos no tempo e no espaço. A idéia é aplicar uma análise integrada sobre o meio ambiente que melhor caracterize os aspectos físicos com ênfase na variação do índice de vegetação de diferença normalizada (IVDN) do ano 1989 para o ano 1997. O propósito é também realizar a caracterização morfométrica do relevo, principalmente com relação à sua declividade, mapear a concentração e distribuição espacial de metais pesados no solo, obtidos por amostragens georreferenciadas do horizonte Bw (camada do solo com profundidade de até 1m) na área de estudo. A metodologia envolve o uso e a integração de documentos cartográficos, tais como mapas topográficos, fotografias aéreas, imagens de satélite e levantamento de campo, cada qual direcionado a uma representação espacial, utilizando-se para sua manipulação de um Sistema de Informações Geográficas (SIG). A proposta é aplicada em uma área pertencente à Baixada Santista, que esta inserida na Carta Topográfica em 1:50.000 do IGG - SP - 1972 FOLHA DE SANTOS. Depois de obtidos os diversos mapas são elaborados estudos de regressão múltipla espacial, os quais demonstram correlações significativas entre as variáveis metais pesados e declividade na mudança dos índices de vegetação para os anos de 1989 e 1997. / The basic approach of the work is to show the importance of the integration of a Geographic Information System (GIS) with geostatístics procedures in the analysis and interpretation of data distributed in time and space. The idea is to apply an environment integrated analysis that better characterizes the geographic landscape with emphasis in the variation of the Normalized Difference Vegetation Index (NDVI) during the years of 1989 to 1997. The purpose is also understand the morphometric characterization of the relief, mainly regarding its slope, mapping concentration and space distribution of heavy metals in the ground, obtained by sampling of the Bw horizon (layer of the ground with depth until 1m), in the study area. The methodology involves the use and the integration of cartographic documents, such as topographical maps, air photographs, satellite images and field survey, each one directed to a space representation of the studied event and manipulated by a Geographic Information System. The proposal study is applied in an area pertaining to the Baixada Santista that is inserted in the 1:50,000 Topographical Chart of the Institute of Geophysics and Geology (IGG) SP. 1972 Folha de Santos. After obtained the diverse maps multiple regression analysis had been elaborated, which demonstrated the significant correlation between changeable heavy metals and slope controlling the vegetation indices change during the studied period of time.

Made available in DSpace on 2015-05-14T12:09:35Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4567922 bytes, checksum: 9d5c646bb1c124ff4e411ed6bc7dc654 (MD5) Previous issue date: 2014-03-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This work aims the implementation of the Index Normalized Difference Vegetation (NDVI) in the study of environmental degradation of watersheds of rivers and river Gramame Abiai-Papocas, both located on the south coast of Paraíba state. The survey was conducted from images of Landsat 5 TM satellite, the years 1989, 2001 and 2006. Initially Atmospheric and radiometric corrections were performed. From the corrected images extracted and it was made thematic maps tracks the NDVI, which highlighted the density of vegetation cover. Then on-site visits, in which sampling points chosen as representative in supervised classification by regions, satellite images, which resulted in the preparation of thematic maps of land use were collected were performed. Topographic information from the Digital Elevation Model (DEM) images The Shuttle Radar Topography Mission (SRTM) thematic maps describing the ground from the height of each pixel in the drainage network relationship were made using the algorithm Height Above the Neareast Drainage (HAND). Then crosses the NDVI data with land use and with the HAND were carried out to justify the responses of NDVI, as well as evaluating its relationship with the land uses and the gap compared the drainage network. From the intersection of NDVI with HAND verified the presence of vegetation with greater biomass in the lower regions. With the crossing of the maps of land use and NDVI was observed that a large number of areas with exposed soils showed NDVI values in the range of -0.25 to 0.15. As for vegetation degradation in river basins, there was a decrease in NDVI values for 2001 and 1989 regeneration 2001 for 2006 observed an increasing convergence of natural vegetation in farmland and urban expansion without planning.; and that much of the degradation are derived from the practice of mining and farming without the use of soil conservation techniques. It was also found that data obtained in research enabled the generation of information that can be used in other research and aid decision makers in formulating geared to minimizing the environmental degradation in the watersheds studied public policy / Esse trabalho teve como objetivo a aplicação do Índice de Vegetação da Diferença Normalizada (IVDN) no estudo da degradação ambiental das bacias hidrográficas do rio Gramame e dos rios Abiai-Papocas, ambas situadas no litoral sul do Estado da Paraíba. A pesquisa foi realizada a partir de imagens do satélite Landsat 5 TM, dos anos de 1989, 2001 e 2006. Inicialmente foram realizadas correções atmosférica e radiométrica. A partir das imagens corrigidas extraiu-se e confeccionou-se os mapas temáticos de faixas do IVDN, que destacaram a densidade da cobertura vegetal. Em seguida foram realizadas visitas in loco, nas quais foram coletados pontos amostrais, adotados como representativos na classificação supervisionada por regiões, das imagens de satélite, que resultou na confecção dos mapas temáticos de uso do solo. Com informações topográficas do Modelo Digital de Elevação (MDE) de imagens The Shuttle Radar Topography Mission (SRTM) foram confeccionados os mapas temáticos da descrição do terreno a partir da altura de cada pixel em relação rede de drenagem, utilizou-se o algoritmo Height Above the Neareast Drainage (HAND). Em seguida, foram realizados cruzamentos dos dados do IVDN com os de uso do solo e com os do HAND, objetivando justificar as repostas do IVDN, assim como, avaliar a relação deste com os usos do solo e com o desnível em relação à rede de drenagem. A partir do cruzamento do IVDN com o HAND foi verificada a presença de vegetação com maior biomassa nas regiões mais baixas. Com o cruzamento dos mapas do uso do solo e do IVDN observou-se que grande parte das áreas com solos expostos apresentaram valores de IVDN na faixa de -0,25 a 0,15. Quanto à degradação da vegetação nas bacias hidrográficas, houve uma diminuição dos valores de IVDN de 1989 para 2001 e uma regeneração de 2001 para 2006. Observou-se um aumento da convergência da vegetação natural em terras agrícolas e em expansões urbanas sem planejamento; e que grande parte das áreas degradadas são proveniente da prática da mineração e da agricultura sem a utilização de técnicas conservacionistas do solo. Verificou-se ainda, que dados obtidos na pesquisa possibilitou a geração de informações que poderão ser utilizadas em outras pesquisas, no auxílio a tomadores de decisão e na formulação de políticas públicas voltadas para a minimização da degradação ambiental nas bacias hidrográfica estudadas

Evapotranspiration (ET) is a significant hydrological process. It can be studied and estimated using remote sensing based methods at multiple spatial and temporal scales. Most commonly and widely used remote sensing based methods to estimate actual evapotranspiration (AET) are a) methods based on energy balance equations, b) vegetation coefficient based method and c) contextual methods. These three methods require reflectance and land surface temperature (LST) data measured at optical and thermal portion of the electromagnetic spectrum. However, these data are available only for clear sky conditions and fail to be retrieved under overcast conditions creating gaps in the data, which result in discontinuous of AET product. Moreover, energy balance equation based methods and evaporative fraction (EF) based contextual methods are difficult to apply over overcast conditions. In this context, vegetation coefficient based (Tasumi et al., 2005; Allen et al., 2005) and microwave remote sensing based methods can be applied under cloudy sky conditions (Sun et al., 2012), since microwave radiations can penetrate through clouds, but these data are available at coarse resolution. In the vegetation coefficient method temporal upscaling can be avoided. Therefore in this research vegetation coefficient based method is employed over Cauvery basin to estimate daily AET for clear and cloudy sky conditions. Required critical variables for this method such as reference evapotranspiration (ETo) and vegetation coefficients are obtained using LST and optical vegetation indices for all sky conditions. In this study, all sky conditions refer to both clear and cloudy sky conditions. Most important variable for estimation of ETo using radiation and temperature based models is air temperature (Ta). In this study, for better accuracy of Ta, two satellite based approaches namely, Temperature Vegetation Index (TVX) and Advance Statistical Approaches (ASA) were evaluated. In the TVX approach, in addition to traditional Normalized Difference Vegetation Index (NDVI), other vegetation indices such as Enhanced Vegetation Index (EVI) and Global Vegetation Moisture Index (GVMI) were also examined. In case of ASA, bootstrap technique was used to generate calibration and validation samples and Levenberg Marquardt algorithm was used to find the solution of the models. The better of the Ta results obtained out of these two approaches were employed in the ETo models and are referred as Ta based ETo models. Instead of Ta, processed LST data obtained directly from the satellite (Aqua/Moderate Resolution Imaging Spectroradiometer (MODIS)) was applied in the ETo models and these are referred as LST based ETo models. These Ta and LST based Hargreaves-Samani (H-S), Makkink (Makk) and Penman Monteith Temperature (PMT) models were evaluated by comparing with the FAO56 PM model. Additionally, simple LST based equation (SLBE) proposed by Rivas et al. (2004) was also examined. Required solar radiation (Rs) data for ETo estimation was obtained from Kalpana1/VHRR satellite data. Results implied that, Ta based PMT model performed better than the Ta based H-S, Makk and SLBE with less RMSE, MAPE and MBE values for all land cover classes and for various climatic regions for clear sky conditions. LST based H-S, PMT, Makk and Ta based Makkink advection models predominantly overestimated ETo for the study region. In the case of TVX approach, to estimate maximum Ta (Tmax), GVMI performed better than NDVI and EVI. Nevertheless, TVX approach poorly estimated Tmax in comparison with statistical approach. ASA performed better for both Tmax and minimum Ta. This study demonstrates the applicability of satellite based Ta and ETo models by considering very few variables for clear sky conditions. Spatially distributed vegetation coefficients (Kv) data with high temporal resolution is another important variable in vegetation coefficient method for daily AET estimation and also it is in demand for crop condition assessment, irrigation scheduling, etc. But available Kv models application hinders because of two main reasons i.e 1) Spectral reflectance based Kv accounts only for transpiration factor but not evaporation, which fails to account for total AET. 2) Required optical spectral reflectances are available only during clear sky conditions, which creates gaps in the Kv data. Hence there is a necessity of a model which accounts for both transpiration and evaporation factors and also gap filling method, which produces accurate continuous quantification of Kv values. Therefore, different combinations of EVI, GVMI and temperature vegetation dryness index (TVDI) have been employed in linear and non linear regression techniques to obtain best model. This best Kv model had been compared with Guershman et al. (2009) Kv model. To fill the gaps in the data, initially, temporal fitting of Kv values have been examined using Savitsky-Goley (SG) filter for three years of data (2012 to 2014), but this fails when sufficient high quality Kv values were unavailable. In this regard, three gap filling techniques namely regression, Artificial Neural Networks (ANNs) and interpolation techniques have been analyzed. Microwave polarization difference index (MPDI) has been employed in ANN technique to estimate Kv values under cloudy sky conditions. The results revealed that the combination of GVMI and TVDI using linear regression technique performed better than other combinations and also yielded better results than Guershman et al. (2009) Kv model. Furthermore, the results indicated that SG filter can be used for temporal fitting and for filling the gaps, regression technique can be used as it performed better than other techniques for Berambadi station. Land Surface Temperature (LST) with high spatiotemporal resolution is required in the estimation of ETo to obtain AET. MODIS is one of the most commonly used sensors owing to its high spatial and temporal availability over the globe, but is incapable of providing LST data under cloudy conditions, resulting in gaps in the data. In contrast, microwave measurements have a capability to penetrate under clouds. The current study proposes a methodology by exploring this property to predict high spatiotemporal resolution LST under cloudy conditions during daytime and night time without employing in-situ LST measurements. To achieve this, ANN based models were employed for different land cover classes, utilizing MPDI at finer resolution with ancillary data. MPDI was derived using resampled (from 0.250 to 1 km) brightness temperatures (Tb) at 36.5 GHz channel of dual polarization from Advance Microwave Scanning Radiometer (AMSR)-Earth Observing System and AMSR2 sensors. The proposed methodology was quantitatively evaluated through three performance measures namely correlation coefficient (r), Nash Sutcliffe Efficiency (NSE) and Root Mean Square Error (RMSE). Results revealed that during daytime, AMSR-E(AMSR2) derived LST under clear sky conditions corresponds well with MODIS LST resulting in values of r ranging from 0.76(0.78) to 0.90(0.96), RMSE from 1.76(1.86) K to 4.34(4.00) K and NSE from 0.58(0.61) to 0.81(0.90) for different land cover classes. For night time, r values ranged from 0.76(0.56) to 0.87(0.90), RMSE from 1.71(1.70) K to 2.43(2.12) K and NSE from 0.43 (0.28) to 0.80(0.81) for different land cover classes. RMSE values found between predicted LST and MODIS LST during daytime under clear sky conditions were within acceptable limits. Under cloudy conditions, results of microwave derived LST were evaluated with Ta which indicated that the approach performed well with RMSE values lesser than the results obtained under clear sky conditions for land cover classes for both day and nighttimes. These predicted LSTs can be applied for the estimation of soil moisture in hydrological studies, in climate studies, ecology, urban climate and environmental studies, etc. AET was estimated for all sky conditions using vegetation coefficient method. Essential parameter ETo under cloudy conditions was estimated using LST and Ta based PMT and H-S models and required solar radiation (Rs) in these two models estimated using equation proposed by Samani (2000). In this equation it was found that the differences between LSTmax or Tmax and LSTmin or Tmin could able to capture the variations due to cloudy sky conditions and hence can be used for estimating ETo under cloudy sky conditions. Results revealed that the estimated Rs correlated well with observed Rs for Berambadi station under cloudy conditions for the year 2013. PMT based ETo values were corresponded with observed ETo under cloudy sky condition. The difference between LST and Ta was less during cloudy conditions, therefore LST or Ta can be used as the only input in temperature based PMT model to estimate ETo. AET estimated correlated well with the observed AET values for clear and cloudy sky conditions. In addition, AET estimated using vegetation coefficient method was compared with two source energy balance (TSEB) method developed by Nishida et al. (2003) under clear sky conditions. It was found that the improved vegetation coefficient method performed better than the TSEB method for Berambadi station. Other microwave vegetation indices such as Microwave Vegetation Indices (MVIs) and Emissivity Difference Vegetation Index (EDVI) are available in literature. Therefore in this study, MVIs are used to predict LST under cloudy conditions using proposed methodology to check whether the MVIs could yield better LST values. Results showed that MPDI performed better than MVIs to predict LST under cloudy sky conditions. Furthermore, MPDI obtained using dual polarizations of 37 GHz channel Tb has advantage of having fine spatial resolution compared to MVIs, as it requires Tb of 19 GHz in addition to Tb of 37 GHz channel which is of coarse resolution and therefore uncertainties resulting from re-sampling technique can be minimized. x

Made available in DSpace on 2015-02-24T20:19:47Z (GMT). No. of bitstreams: 1 SebastiaoCJ_DISSERT.pdf: 3305443 bytes, checksum: 12fd9401dd1cf23c4a8b8b849f63f5d2 (MD5) Previous issue date: 2011-02-18 / The human interference in the semiarid region of Serid? Potiguar has promoted the increase of degraded areas. The economic dynamic that was established in the Serid? territory, especially after the fall of the trinomial cattle-cotton-mining in the 70s and 80s of the 20th century as pillars of the regional economy, resulted in an accelerated process of erosion of natural resources. The municipalities of the Serid? region have been spatially reordered by this new economic dynamic, marked by the growth of existing enterprises, and the development of new agricultural practices. One of the municipalities in the region that restructured its territorial space with the emergence of new agro-industrial activities was the town of Parelhas. With the demise of the trinomial cattle-cotton-mining in the 1980s, other productive activities were intensified from the 1990s, amongst them, pottery, responsible for the vegetal extraction for use as energy source. This recent economic and spatial restructuring in the region, reflected in the Parelhense municipal territory, required new productive ingredients responsible for the modification of past production relations that were based on cattle, cotton and mining. By that a process of exploring the environment was unleashed, especially the native vegetation, in an uncontrolled manner. In this context, the objective of this study was to survey and detect deforestation in the areas of Caatinga vegetation, used indiscriminately as energy supply for new agricultural practices, using remote sensing techniques based on the quantification of the Normalized Difference Vegetation Index / NDVI, Soil-Adjusted Vegetation Index / SAVI, surface temperature and rainfall data in the years 1990 and 2010. The results indicated that SAVI values above 0.2 in 1990 and 2010 represent the areas with the highest density of vegetation that occur exclusively along the major drainages in the town and areas of higher elevations. The areas between the ranges of values from 0.5 to 0.15 SAVI are areas with poor vegetation. On the other hand the highest values of temperature are distributed in the western and southeastern parts of the township, usually in places where the soil is exposed or there is sparse vegetation. The areas of bare soil decreased in extension in 2010 at 11, 6% when related to 1990, this was caused by a higher rainfall intensity in the first half of 2010, but no regeneration of vegetation occurred in some places in the western and southeastern areas of the municipality today, due to the extraction of firewood to fuel the furnaces of industries in town / A interfer?ncia antr?pica na regi?o Semi?rida do Serid? Potiguar vem desencadeando o aumento de ?reas degradadas. A din?mica econ?mica que se estabeleceu no territ?rio seridoense, sobretudo ap?s a queda do trin?mio gado, algod?o e minera??o nas d?cadas de 70 e nas d?cadas de 80 do s?culo XX, como pilares da economia da regi?o, implicaram num acelerado processo de desgaste dos recursos naturais. Os territ?rios municipais da regi?o do Serid? v?m sendo reordenado espacialmente por essa nova din?mica econ?mica, marcada pelo crescimento dos empreendimentos j? existentes, al?m do desenvolvimento de novas atividades agroindustriais. Um dos munic?pios do Serid? potiguar que teve seu espa?o territorial reestruturado com o surgimento de novas atividades agroindustriais foi o de Parelhas. Com a derrocada do trin?mio gado, algod?o e minera??o, na d?cada de 1980, outras atividades produtivas foram intensificadas a partir da d?cada de 1990, dentre elas a ceramista, respons?vel pela extra??o vegetal para utiliza??o como fonte energ?tica. Essa recente reestrutura??o espacial e econ?mica regional, refletida no territ?rio municipal parelhense, tem requerido novos ingredientes produtivos, respons?veis pela modifica??o das rela??es de produ??o pret?ritas que antes eram baseadas na pecu?ria, no algod?o e na minera??o. Com isso, desencadeou-se um processo de explora??o do meio ambiente, em especial da vegeta??o nativa, de forma descontrolada. Nesse contexto o objetivo deste trabalho foi fazer o levantamento e a detec??o do desmatamento das ?reas de vegeta??o de caatinga, usadas indiscriminadamente para o abastecimento energ?tico das novas atividades agroindustriais, utilizando t?cnicas de sensoriamento remoto a partir da quantifica??o do ?ndice de Vegeta??o Diferen?a Normalizada/NDVI, do ?ndice de Vegeta??o Ajustado ao Solo/SAVI, da temperatura da superf?cie e de dados pluviom?tricos nos anos de 1990 e 2010. Os resultados indicaram que os valores de SAVI acima de 0,2 em 1990 e 2010 representam as ?reas com maior densidade de vegeta??o que ocorrem, exclusivamente, ao longo das drenagens principais do munic?pio e nas ?reas de maiores eleva??es. As ?reas que est?o entre os intervalos de valores de SAVI de 0,5 at? 0,15 s?o ?reas com pouca cobertura vegetal. J? os valores mais altos de temperatura distribuem-se na ?rea oeste e sudeste do munic?pio, geralmente em locais onde o solo est? exposto ou possui vegeta??o pouco densa. As ?reas de solo exposto diminu?ram sua extens?o, em 2010, cerca de 11, 6% quando relacionada a 1990, isto foi ocasionado por uma intensidade pluviom?trica maior no primeiro semestre de 2010, por?m n?o houve regenera??o da vegeta??o em alguns locais nas ?reas Oeste e Sudeste do munic?pio nesta data, devido ? extra??o de lenha para abastecer os fornos das ind?strias do munic?pio

A alta fragmentação da cobertura original da Bacia do Rio Corumbataí, SP, ocasionada principalmente por atividades agropecuárias, resultou em remanescentes florestais em diferentes condições ecológicas, em função dos aspectos físicos, naturais e antrópicos, do meio em que estão inseridos. Neste trabalho esses fragmentos foram analisados individualmente, considerando-se a estrutura da paisagem de seu entorno, por meio de uma caracterização física e estrutural, tendo o Índice de Vegetação da Diferença Normalizada (NDVI) como variável-chave, em função da sua relação com o vigor da vegetação. O presente estudo teve como objetivo principal analisar a relação entre NDVI dos remanescentes e variáveis físicas do ambiente (relevo, distância à rede hidrográfica, áreas urbanas, estradas e precipitação), além de variáveis estruturais dos próprios fragmentos (forma, área, área nuclear, distância do vizinho mais próximo, contraste de borda e perímetro). Também foi verificada a alteração da cobertura florestal da bacia entre os anos de 1999 e 2002, a fim de compreender melhor as suas condições de conservação. Como principais resultados foi constatado uma relação inversa entre NDVI e algumas variáveis físicas e estruturais como por exemplo o contraste de borda, a distância à rede hidrográfica, a distância ao vizinho mais próximo e a área total; já a área nuclear, a declividade e a distância às estradas apresentaram uma relação direta com o NDVI. A perda de vegetação nativa entre 1999 e 2002, foi maior que o acréscimo (1.886 ha e 895 ha, respectivamente), tendo ocorrido em maior proporção nos fragmentos mais próximos às áreas urbanas. Fragmentos com as maiores áreas nucleares, mais próximos à rede hidrográfica e em terrenos mais declivosos foram aqueles que apresentaram maiores valores de NDVI. Os resultados mostraram que características físicas e estruturais dos fragmentos podem influenciar o vigor da vegetação e, conseqüentemente, o seu estado de conservação. / Forest fragmentation of Corumbataí river basin caused by agriculture dominance directly affects the condition of forest remnants to support plant and animal species. These forest patches present different ecological conditions, depending on many physical and anthropogenic aspects of the landscape they are inserted. In this study, forest patches were individually analyzed considering their landscape structure and the Normalized Difference Vegetation Index (NDVI) as response variable, due to its relationship to vegetation vigor. The main objective was to analyze the relationship between forest patches NDVI, physical variables of landscape (relief, distance to rivers, distance to roads, distance to urban areas and precipitation) and forest patches landscape structure (shape, area, core area, nearest neighbor distance, edge contrast and perimeter). Also, forest cover changes between 1999 and 2002 were analyzed in order to understand better patches conditions and their relation to landscape variables. As results, we found an inverse relationship between NDVI and distance to rivers, edge contrast, nearest neighbor distance and total area. Core area, slope and distance to roads presented direct relationship to NDVI. Forest losses between 1999 and 2002 were greater than gains (1886 ha and 895 ha, respectively), and they occurred commonly near urban areas. Greater NDVI values were observed on patches with large core areas, near to rivers and on high slope areas. The results showed that physical and structural patches characteristics have influence on vegetation vigor and, consequently, on their conservation status.