Changes in riparian forest cover from 1966 to 2017 along the Paraíba do Sul River between Jacareí and Queluz, São Paulo, Brazil ; Alterações na cobertura florestal da mata ciliar ao Rio Paraíba do Sul, entre os anos de 1966 e 2017, no trecho Jacareí-Queluz, São Paulo, Brasil
This study is based on the assumption that beginning with the passage of the Forest Code in 1965, which was revised by the law of 2012, the Permanent Preservation Area (PPA) of Paraíba do Sul River, PSR, is currently recuperated and preserved. In this context, the objective of this study was to: 1) conduct a temporal survey with respect to the rate of change of gains and losses of forest cover during the years 1966, 1977 and 2017; and, 2) do a spatial analysis in relation to this rate of change. This study was conducted along the stretch of the PSR between the municipalities of Jacareí and Queluz. Maps were used from the Brazilian Institute of Geography and Statistics - IBGE (1964-1966), the Geographic and Cartographic Institute of the state of São Paulo – IGC-SP (1978) (IGC), and high resolution images from the Pléiades satellite (2017). For the spatial and temporal analyses of the study area, geoprocessing techniques were used to quantify the area occupied by forest in two: 100 m buffer strips of the PPA, and in buffer strips of 1,000m, starting from each bank of the river. With respect to forest cover, measurements of its total and average size, proportion, gain or loss, and distance between nearby fragments were made. The results indicate that, from the decade of the 1960s to 2017, forest cover grew from 5.3% to 21%, and from 2% to 13% in the strips of 100 and 1,000 meters, respectively. With respect to areas registered from 1960, there was a reduction of 691 hectares, principally of large areas of remaining forest. However, a portion of this forest area was still present in 2017, but most of this forest was in the area 1,000 m from the riverbanks. These results will aid in the planning for establishment of priority areas for conservation of the riparian forest of the PSR. Through analysis of distances between forest fragments, empty spaces devoid of forest cover were identified, and in some cases these spaces were indicated as priority areas for recuperation. The results are discussed in the context of public policies and the periods of economic development that were drivers of landscape changes in the Paraíba do Sul Valley in the São Paulo region. In conclusion, the results demonstrate that the riparian forest of the PSR has slowly recuperated but is still far from being in compliance with current Brazilian legislation. This study will be an important aid in compliance activities conducted by public authorities in permanent preservation areas in the São Paulo PSR. An ample and refined survey of consolidated and fallow areas is suggested so that mitigation and compensation activities can be proposed for the PSR riparian forest that will promote the conservation of the quality of its water and biodiversity resources. ; This study is based on the assumption that beginning with the passage of the Forest Code in 1965, which was revised by the law of 2012, the Permanent Preservation Area (PPA) of Paraíba do Sul River, PSR, is currently recuperated and preserved. In this context, the objective of this study was to: 1) conduct a temporal survey with respect to the rate of change of gains and losses of forest cover during the years 1966, 1977 and 2017; and, 2) do a spatial analysis in relation to this rate of change. This study was conducted along the stretch of the PSR between the municipalities of Jacareí and Queluz. Maps were used from the Brazilian Institute of Geography and Statistics - IBGE (1964-1966), the Geographic and Cartographic Institute of the state of São Paulo – IGC-SP (1978) (IGC), and high resolution images from the Pléiades satellite (2017). For the spatial and temporal analyses of the study area, geoprocessing techniques were used to quantify the area occupied by forest in two: 100 m buffer strips of the PPA, and in buffer strips of 1,000m, starting from each bank of the river. With respect to forest cover, measurements of its total and average size, proportion, gain or loss, and distance between nearby fragments were made. The results indicate that, from the decade of the 1960s to 2017, forest cover grew from 5.3% to 21%, and from 2% to 13% in the strips of 100 and 1,000 meters, respectively. With respect to areas registered from 1960, there was a reduction of 691 hectares, principally of large areas of remaining forest. However, a portion of this forest area was still present in 2017, but most of this forest was in the area 1,000 m from the riverbanks. These results will aid in the planning for establishment of priority areas for conservation of the riparian forest of the PSR. Through analysis of distances between forest fragments, empty spaces devoid of forest cover were identified, and in some cases these spaces were indicated as priority areas for recuperation. The results are discussed in the context of public policies and the periods of economic development that were drivers of landscape changes in the Paraíba do Sul Valley in the São Paulo region. In conclusion, the results demonstrate that the riparian forest of the PSR has slowly recuperated but is still far from being in compliance with current Brazilian legislation. This study will be an important aid in compliance activities conducted by public authorities in permanent preservation areas in the São Paulo PSR. An ample and refined survey of consolidated and fallow areas is suggested so that mitigation and compensation activities can be proposed for the PSR riparian forest that will promote the conservation of the quality of its water and biodiversity resources. ; Este trabalho parte do pressuposto que a partir da promulgação do Código Florestal em 1965, reafirmada na revisão da Lei em 2012, a Área de Preservação Permanente (APP) do Rio Paraíba do Sul, PRS, encontra-se recuperada e preservada. Dessa forma, o presente trabalho teve como objetivo (1) realizar um levantamento temporal, compreendendo os anos de 1966, 1977 e 2017 e (2) um levantamento espacial, a partir das taxas de mudanças compreendendo ganhos e perdas na cobertura florestal. O trabalho foi realizado no trecho do RPS paulista entre os municípios de Jacareí a Queluz. Foram utilizadas as cartas do Instituto Brasileiro de Geografia e Estatística - IBGE (1964-1966), do Instituto Geográfico e Cartográfico do Estado de São Paulo – IGC-SP (1978) (IGC) e imagens de alta resolução do satélite Pléiades (2017). Para análise espacial e temporal da área de estudo, foram utilizadas técnicas de geoprocessamento quanto a área de ocupação da floresta em duas faixas: 100 m (Área de Preservação Permanente - APP) e 1000 m a partir de ambas as margens. Foram obtidas métricas quanto ao tamanho total e médio da cobertura florestal, proporção de ocupação das áreas de florestas, ganho/perda de áreas coberta por floresta e distância entre os fragmentos mais próximos. Os resultados revelaram que da década 60 até 2017 a cobertura florestal passou de 5,3% para 21% e de 2% para 13% nas faixas de 100 e 1000 metros, respectivamente. Quanto as áreas registradas em 1960, grande parte sofreu redução, uma perda de 691 hectares principalmente dos grandes remanescentes florestais. Entretanto, parte desses remanescentes florestais, permaneceram até 2017, porém, grande parte dessas áreas encontram-se na faixa de 1000 m de distância da margem. Esses resultados permitiram avaliar e sugerir áreas prioritárias para a conservação da mata ciliar ao RPS. A partir da análise das distâncias entre os fragmentos florestais, foram identificados espaços vazios, desprovidos de cobertura florestal e em alguns casos foram indicados como áreas prioritárias para recuperação. Os resultados evidenciaram que, lentamente, parte da mata ciliar ao RPS se recuperou, mas ainda está longe de satisfazer a legislação vigente no país. Esse trabalho pode ser útil para auxiliar a fiscalização das áreas de preservação permanente ao RPS paulista. Ao final considera-se necessário um amplo e minucioso levantamento das áreas de pousio e consolidadas para que sejam propostas ações de mitigação e compensação da mata ciliar ao Rio Paraíba do Sul e subsidiar a conservação da qualidade do recurso hídrico e da biodiversidade.