Uma característica marcante do processo contemporâneo de urbanização em diversas regiões do país e do mundo é a expansão cada vez mais extensiva da mancha urbana sobre o território, conformando núcleos urbanos dispersos e territorialmente desagregados do conjunto urbano principal. No contexto da Região Metropolitana de São Paulo (RMSP), a dispersão urbana se materializa pelo espraiamento difuso de loteamentos clandestinos e de condomínios fechados de alto e médio padrão nas franjas urbanas, consolidando áreas periféricas ainda mais complexas do que aquelas que predominaram até a década de 1980. Um dos principais impactos dessa forma de expansão é a degradação do Cinturão Verde da Cidade de São Paulo, com sérias consequências para a população e para qualidade ambiental urbana metropolitana. O principal objetivo desta tese é estudar o papel das formas contemporâneas de urbanização na supressão da cobertura vegetal em áreas periféricas, tomando como objeto de estudo a Região Metropolitana de São Paulo. O recorte temporal se estende da década de 1980 até os dias atuais, quando as principais características dos processos contemporâneos de urbanização se tornaram mais nítidas. A questão que dá suporte ao trabalho é a de que esses processos apresentam características distintas em relação aos padrões anteriores de urbanização, alterando, consequentemente, a natureza dos impactos que provocam sobre os recursos vegetais. O agravamento dos problemas ambientais urbanos, associado ao novo quadro de urbanização, exige a realização de estudos empíricos teoricamente embasados que possam ampliar a compreensão desse processo e subsidiar a formulação de políticas públicas mais afinadas ao novo contexto. / One striking feature of the current urbanization process seen in several regions of Brazil and throughout the world is the increasing urban sprawl across the land, and the shaping of more dispersed urban nuclei that are isolated from the main urban setting. Within the context of the São Paulo Metropolitan Region (RMSP), urban sprawl is seen in the diffusion of both slums and mid-high income gated properties in the urban suburbs, producing peripheral areas that are even more complex than those seen in the 80s. One of the main impacts of this type of expansion is the degradation of the city of São Paulos Green Belt, which has severe consequences on the metropoliss people and its environment. The main objective of this research is to study the role of contemporary urban forms in the suppression of vegetation in peripheral areas, with a focus on the Metropolitan Region of São Paulo. The time frame ranges from the 1980s to present time, when the main features of these contemporary processes have become clearer. The idea behind this study is that these processes present distinct traits in relation to the previous patterns of urbanization, therefore changing the nature of the impact on natural plant resources. The rising urban environmental problems related to this new urbanization scenario call for theoretically-based empirical studies in order to better understand the process and to support the creation of public policies that are better aligned with this new context.

Uma característica marcante do processo contemporâneo de urbanização em diversas regiões do país e do mundo é a expansão cada vez mais extensiva da mancha urbana sobre o território, conformando núcleos urbanos dispersos e territorialmente desagregados do conjunto urbano principal. No contexto da Região Metropolitana de São Paulo (RMSP), a dispersão urbana se materializa pelo espraiamento difuso de loteamentos clandestinos e de condomínios fechados de alto e médio padrão nas franjas urbanas, consolidando áreas periféricas ainda mais complexas do que aquelas que predominaram até a década de 1980. Um dos principais impactos dessa forma de expansão é a degradação do Cinturão Verde da Cidade de São Paulo, com sérias consequências para a população e para qualidade ambiental urbana metropolitana. O principal objetivo desta tese é estudar o papel das formas contemporâneas de urbanização na supressão da cobertura vegetal em áreas periféricas, tomando como objeto de estudo a Região Metropolitana de São Paulo. O recorte temporal se estende da década de 1980 até os dias atuais, quando as principais características dos processos contemporâneos de urbanização se tornaram mais nítidas. A questão que dá suporte ao trabalho é a de que esses processos apresentam características distintas em relação aos padrões anteriores de urbanização, alterando, consequentemente, a natureza dos impactos que provocam sobre os recursos vegetais. O agravamento dos problemas ambientais urbanos, associado ao novo quadro de urbanização, exige a realização de estudos empíricos teoricamente embasados que possam ampliar a compreensão desse processo e subsidiar a formulação de políticas públicas mais afinadas ao novo contexto. / One striking feature of the current urbanization process seen in several regions of Brazil and throughout the world is the increasing urban sprawl across the land, and the shaping of more dispersed urban nuclei that are isolated from the main urban setting. Within the context of the São Paulo Metropolitan Region (RMSP), urban sprawl is seen in the diffusion of both slums and mid-high income gated properties in the urban suburbs, producing peripheral areas that are even more complex than those seen in the 80s. One of the main impacts of this type of expansion is the degradation of the city of São Paulos Green Belt, which has severe consequences on the metropoliss people and its environment. The main objective of this research is to study the role of contemporary urban forms in the suppression of vegetation in peripheral areas, with a focus on the Metropolitan Region of São Paulo. The time frame ranges from the 1980s to present time, when the main features of these contemporary processes have become clearer. The idea behind this study is that these processes present distinct traits in relation to the previous patterns of urbanization, therefore changing the nature of the impact on natural plant resources. The rising urban environmental problems related to this new urbanization scenario call for theoretically-based empirical studies in order to better understand the process and to support the creation of public policies that are better aligned with this new context.

Soil spectroscopy is a promising technique for soil analysis, and has been successfully utilized in the laboratory. When it comes to space, the presence of vegetation significantly affects the performance of imaging spectroscopy or hyperspectral imaging on the retrieval of topsoil properties. The Forced Invariance Approach has been proven able to effectively suppress the vegetation contribution to the mixed image pixel. It takes advantage of scene statistics and requires no specific a priori knowledge of the referenced spectra. However, the approach is still mainly limited to lithological mapping. In this case study, the objective was to test the performance of the Forced Invariance Approach to improve the estimation accuracy of soil salinity for an agricultural area located in the semi-arid region of Northwest China using airborne hyperspectral data. The ground truth data was obtained from an eco-hydrological wireless sensing network. The relationship between Normalized Difference Vegetation Index (NDVI) and soil salinity is discussed. The results demonstrate that the Forced Invariance Approach is able to improve the retrieval accuracy of soil salinity at a depth of 10 cm, as indicated by a higher value for the coefficient of determination (R2). Consequently, the vegetation suppression method has the potential to improve quantitative estimation of soil properties with multivariate statistical methods.

Soil spectroscopy is a promising technique for soil analysis, and has been successfully utilized in the laboratory. When it comes to space, the presence of vegetation significantly affects the performance of imaging spectroscopy or hyperspectral imaging on the retrieval of topsoil properties. The Forced Invariance Approach has been proven able to effectively suppress the vegetation contribution to the mixed image pixel. It takes advantage of scene statistics and requires no specific a priori knowledge of the referenced spectra. However, the approach is still mainly limited to lithological mapping. In this case study, the objective was to test the performance of the Forced Invariance Approach to improve the estimation accuracy of soil salinity for an agricultural area located in the semi-arid region of Northwest China using airborne hyperspectral data. The ground truth data was obtained from an eco-hydrological wireless sensing network. The relationship between Normalized Difference Vegetation Index (NDVI) and soil salinity is discussed. The results demonstrate that the Forced Invariance Approach is able to improve the retrieval accuracy of soil salinity at a depth of 10 cm, as indicated by a higher value for the coefficient of determination (R2). Consequently, the vegetation suppression method has the potential to improve quantitative estimation of soil properties with multivariate statistical methods.