[1] We describe spatiotemporal variation in land cover over 80,000 km 2 in central Rondônia. We use a multistage process to map primary forest, pasture, second growth, urban, rock/savanna, and water using 33 Landsat scenes acquired over three contiguous areas between 1975 and 1999. Accuracy of the 1999 classified maps was assessed as exceeding 85% based on digital airborne videography. Rondônia is highly fragmented, in which forests outside of restricted areas consist of numerous, small irregular patches. Pastures in Rondônia persist over many years and are not typically abandoned to second growth, which when present rarely remains unchanged longer than 8 years. Within the state, annual deforestation rates, pasture area, and ratio of second growth to cleared area varied spatially. Highest initial deforestation rates occurred in the southeast (Luiza), at over 2%, increasing to 3% by the late 1990s. In this area, the percentage of cleared land in second growth averaged 18% and few pastures were abandoned. In central Rondônia (Ji-Paraná), deforestation rates rose from 1.2% between 1978 and 1986 to a high of 4.2% in 1999. In the northwest (Ariquemes), initial deforestation rates were lowest at 0.5% but rose substantially in the late 1990s, peaking at 3% in 1998. The ratio of second growth to cleared area was more than double the ratio in Luiza and few pastures remained unchanged beyond 8 years. Land clearing was most intense close to the major highway, BR364, except in Ariquemes. Intense forest clearing extended at least 50 km along the margins of BR364 in Ji-Paraná and Luiza. Spatial differences in land use are hypothesized to result from a combination of economic factors and soil fertility.
Hídricos (SIGRHI) e ao definir os princípios básicos para a gestão da água, adotou a bacia hidrográfica como unidade territorial para estudos, planejamento integrado para o desenvolvimento sustentável. O presente trabalho objetivou caracterizar a morfometria das sub-bacias hidrográficas Fojo e Perdizes, no município de Campos do Jordão, SP. A análise morfométrica envolveu a caracterização de parâmetros geométricos, do relevo, da rede de drenagem, e a análise do uso e ocupação do solo das sub-bacias. Na caracterização morfométrica foi encontrada para sub-bacia Perdizes a área de 12,70 km², o perímetro de 19,85 km e o comprimento do eixo da bacia de 6,86 km, enquanto para a sub-bacia Fojo, a área de drenagem encontrada foi de 13,97 km², o perímetro de 19,74 km e o comprimento do eixo da bacia de 6,94 km. Esses resultados indicam semelhanças entre as duas sub-bacias. O coeficiente de compacidade (Kc) encontrado, 1,56 para a sub-bacia Perdizes e 1,41 para a sub-bacia Fojo, associados aos respectivos fatores de forma, F= 0,27 e F = 0,29 indicam que estas sub-bacias, em condições normais de precipitação, são pouco suscetíveis a enchentes. O resultado desses índices é reforçado pelo índice de circularidade encontrado, IC = 0,41 para Perdizes e IC = 0,45 para Fojo, pois o afastamento da unidade indica que as sub-bacias não tendem à forma circular, ou seja, possuem forma mais alongada e, portanto, possuem menor concentração de deflúvio. Os resultados obtidos para o Coeficiente de manutenção (Cm) indicam que para manter cada metro de canal, são necessários 286,5 m² para Perdizes e 243,9 m² para Fojo. A análise do uso e ocupação do solo revelou que dos quatro tipos de coberturas vegetais existentes: a cobertura vegetal dominante nas duas sub-bacias é de Floresta com 649 ha (51,1%) na Perdizes e 608,8 ha (43,6%) na Fojo; a cobertura Reflorestamento aparece em segundo lugar, ocupa área muito semelhante nas duas sub-bacias, 218 ha (17,2%) na Perdizes e aproximadamente 214 ha (15,3%) na Fojo. Em termos de conservação, a sub-bacia Fojo apresenta-se melhor conservada, pois além de menor área urbanizada, apresenta ainda, maior área com cobertura do tipo campo e uma área de floresta apenas um pouco menor que da sub-bacia Perdizes. Palavras-chave: drenagem, uso do solo, escoamento superficial, manejo de bacias.
Increased urbanization typically leads to an increase in abundance of a few species and a reduction in bird species richness. Understanding the structure of biotic communities in urban areas will allow us to propose management techniques and to decrease conflicts between wild species and human beings. The objective of this study was to describe the structure of the bird community in an urban ecosystem. The study was carried out in the city of Taubaté in southeastern Brazil. Point-counts were established in areas with different levels of tree density ranging from urban green spaces to predominantly built-up areas. We looked for a correlation between the richness/abundance of birds and the size of the area surveyed, the number of houses, the number of tree species and the number of individual trees. The results of multiple regression showed that bird richness had a direct relationship with vegetation complexity. The abundance and diversity of tree species were better predictors of bird species than the number of houses and size of the area surveyed. We discuss implications of this study for conservation and management of bird diversity in urban areas, such as the need to increase green areas containing a large diversity of native plant species.
We have analysed monthly composites of normalized diVerence vegetation index (NDVI ) calculated from NOAA's Advanced Very High Resolution Radiometer (AVHRR) for the Amazonian region of northern Brazil across a decade (August 1981 to June 1991 to ascertain if the dominant vegetation types could be diVerentiated, and to seek inter-annual climatic variation due to changing environmental conditions. The vegetation types observed included dense forest (submontana and terras baixas), open forest (submontana and terras baixas), transitional forest, seasonal forest (caatinga), and two types of savanna (cerrado). We found that monthly NDVI composites revealed seasonality in cerrado and especially in caatinga cover types, which can be used in their identi® cation, whilst the phenology of other forest cover types varies little throughout the year. Additionally, yearly composite NDVI values showed a clear and signi® cant reduction ( p>0´95) in dry years, such as those with El Nin Ä o Southern Oscillation events. These results indicate the potential use of multi-temporal NDVI data for the environmental characterization and identi® cation of forest ecosystems. Our research found NDVI images from NOAA AVHRR oVer a long-term data set that is unequalled for monitoring terrestrial land cover. However, these data have to be used with a degree of caution, especially in regards to atmospheric interference, such as cloud contamination and volcanic eruptions, and post-launch changes in calibration.
OBJETIVO: Analisar os padrões de distribuição espacial da mortalidade neonatal. MÉTODOS: Estudo ecológico e exploratório, utilizando técnicas de análise espacial dos dados de mortalidade neonatal no Vale do Paraíba paulista, nos anos 1999-2001. A análise estatística espacial utilizou uma base de dados georreferenciados de 35 municípios e rotinas de estatística espacial. Os dados de mortalidade foram obtidos na Secretaria de Estado da Saúde de São Paulo. As variáveis estudadas foram os coeficientes de mortalidade neonatal precoce, tardia e total, e o Índice de Desenvolvimento Humano relativos ao ano de 2000. Para avaliação da dependência espacial foram utilizados os coeficientes de autocorrelação de Moran global e o Índice de Moran local e analisadas as correlações entre as variáveis. RESULTADOS: Foram registrados 111.574 nascidos vivos, com 1.149 óbitos no período neonatal precoce (10,29/1.000 nascidos vivos), 285 no neonatal tardio (2,55/1.000 nascidos vivos) totalizando 1.434 óbitos no período neonatal (12,85/1.000 nascidos vivos). Os coeficientes de Moran (global) mostraram significância estatística (p<0,05) para as mortalidades neonatal precoce e neonatal total. Os índices locais mostraram agrupamentos de municípios onde ocorre dependência espacial na ocorrência das mortalidades precoce e total. CONCLUSÕES: A análise espacial permitiu identificar aglomerado espacial no médio Vale do Paraíba tanto para a mortalidade neonatal precoce como para a neonatal total.
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