Abstract Brazil has the most populous and biodiverse semi-arid region in the world (Brazilian Semi-arid - SAB). However, in recent decades, clusters of desertification have emerged, a problem that could intensify from climate change. The objective of this study was to elaborate on the spatial distribution of areas susceptible to climatic desertification in the SAB, considering future climate change scenarios. Understanding this dynamic is essential for SAB's agri-environmental management. Aridity indices and proposition of climate classes for current condition (1970-2000) and future scenarios (2061-2080) of the Intergovernmental Panel on Climate Change (IPCC) were prepared, considering scenarios from Shared Socioeconomic Pathways: Optimistic (SSP 126) and pessimists (SSP 585). The results indicate that by the end of the century, the climate in the SAB should become significantly drier (Kruskal-Wallis = p-value < 0.05), with an intensification of the aridity index in SSP 585. In the scenarios, the expansion of more arid areas over humid climates could reach 56,500 km2 (10%) in SSP 126 and 140,400 km2 (24%) in SSP 585. Consequently, areas with high (622,400 km2 to 706,300 km2) and very high (622,400 km2 to 706,300 km2) are expected to expand. 4,400 to 21,700 km2) susceptibility to climate desertification in the SAB, respectively in scenarios SSPs 126 and 585. Confirming these projections would imply socioeconomic and ecological risks in the SAB.

Resumo O Brasil possui a região semiárida mais populosa e de maior biodiversidade do mundo (Semiárido Brasileiro - SAB). No entanto, nas últimas décadas, núcleos de desertificação têm surgido, um problema que pode intensificar a partir de mudanças climáticas. O objetivo desse estudo foi elaborar a distribuição espacial das áreas suscetíveis à desertificação climática no SAB, considerando cenários futuros de mudanças do clima. O entendimento dessa dinâmica é algo essencial para a gestão agroambiental do SAB. Foram elaborados índices de aridez e proposição de classes climáticas para condição atual (1970-2000) e cenários futuros (2061-2080) do Painel Intergovernamental sobre Mudanças Climáticas (IPCC), levando em conta cenários do Caminhos Socioeconômicos Compartilhados: otimistas (SSP 126) e pessimistas (SSP 585). Os resultados indicam que até o final do século, o clima no SAB deverá tornar-se significativamente mais seco (Kruskal-Wallis = p-value < 0,05), com intensificação do índice de aridez no SSP 585. Nos cenários, a expansão de áreas mais áridas sobre climas úmidos pode alcançar 56.500 km2 (10%) no SSP 126 e 140,400 km2 (24%) no SSP 585. Consequentemente, espera-se expansão das áreas com alta (622,400 km2 a 706,300 km2) e muito alta (4,400 a 21,700 km2) suscetibilidade à desertificação climática no SAB, respectivamente nos cenários SSPs 126 e 585. Confirmando essas projeções, implicaria em riscos socioeconômicos e ecológicos no SAB.

ABSTRACT This study analyzed the use of the water balance, precipitation, temperature and NDVI (Normalized Difference Vegetation Index) to determine the optimum moment for evaluating infestation by the nematode Meloidogyne exigua in a rubber tree plantation by remote sensing. Nineteen sampling points were defined, divided into three areas, with high and low defoliation degrees, on a property in the Triângulo Mineiro region, where soil and root samples were collected for nematological analysis. Monthly digital images (OLI - Landsat 8 sensor) were obtained from August 2015 to August 2016. Rainfall, temperature and water balance were analyzed. The latter had no correlation with the indices; in contrast, temperature and precipitation correlated directly with NDVI. The best months for nematode soil infestation analysis were December, January and February, while for root infection it was August.

ABSTRACT In Brazil there are six well-defined biomes and the Caatinga represents 9.92% of the total area. This biome is exclusively Brazilian and very rich in biodiversity. Because it has low resistance to human interference is necessary to know the important factors in monitoring the biome. Vegetation coverage and climate are two of these factors, as they indicate the intensity of human activity and the wear caused with time. Normalized Difference Vegetation Index (NDVI) has been recently explored in the description of tree phenology. In this study we sought to associate NDVI/Landsat values to a climatic variable (phenomena El-Nino and La-Nina - NINONINA) in order to describe the phenological behavior of the Caatinga in the Parque Nacional da Serra das Capivaras in the state of Piauí/Brazil. A time series analysis was carried out, describing the intrinsic parameters of the series (Seasonality and Trends), the forecast of NDVI values using SARIMA model and co-integration between NDVI and NINONINA series. The results showed that the NDVI series presents seasonally, but does not exhibit a trend. The forecasting process presenting relatively low error at a 95% confidence interval. Finally, it was observed that the NDVI series is co-integrated with the NINONINA series.

Resumo O fenômeno da ilha do calor é um dos muitos problemas graves causados pelo rápido crescimento urbano. Assim, os objetivos deste estudo foram: caracterizar e quantificar ilhas de calor em Uberlândia, avaliar a sazonalidade destas ilhas (inverno-verão) e identificar o efeito da cobertura superficial na intensidade das mesmas. Para identificar as ilhas de calor intra-urbanas em Uberlândia, os dados de temperatura do ar foram coletados em duas estações (inverno e verão) usando transectos móveis e estações climáticas fixas. As medidas de transição foram gravadas automaticamente a cada 0,5 segundos usando um termo-higrometro montado em carro movendo-se a uma média de 40 km h-1. O GPS foi usado para selecionar aproximadamente dez pontos de dados a cada 500 metros de cada transecto. As estações meteorológicas fixas mediram a temperatura do ar em três locais da região. A análise dos dados mostrou que as ilhas de calor intra-urbana em Uberlândia foram mais intensas no inverno (ΔT = 2,2ºC) que no verão (ΔT = 1,2ºC) devido principalmente à redução no vapor de água atmosférico no inverno (estação seca) e pela taxa de resfriamento radiativo maior nas áreas permeáveis. A metodologia utilizada no presente estudo mostrou ser uma maneira rápida e eficiente de realizar esse tipo de monitoramento.

Abstract The “heat island” phenomenon is one of many serious problems caused by rapid urban growth. This study therefore sought to characterize and quantify heat islands in Uberlandia, to evaluate the seasonality of these islands (winter-summer) and to identify the effect of surface coverage on their intensity. To identify intra-urban heat islands in Uberlandia, air temperature data were collected in two seasons (winter and summer) using mobile and fixed transects seasons. Transition measurements were recorded automatically every 0.5 seconds using a car-mounted thermos-hygrometer moving at an average of 40 km h-1. GPS was used to select approximately ten data points every 500 meters of each transect. Fixed weather stations measured air temperature at three sites in the region. Transect data analysis showed that the intra-urban heat islands were more intense in winter (ΔT = 2.2ºC) than in summer (ΔT = 1.2ºC) mainly because by reduction in atmospheric vapor in winter (dry season) and by higher rate of radiative cooling that is favored in permeable areas. The methodology used in the present study proved to be a quick and efficient way to carry out this type of monitoring.