RESUMO A leptospirose é um problema de saúde pública mundial. No Brasil, ela é uma doença de notificação compulsória e está relacionada a áreas com precárias condições sanitárias. Foi realizado um estudo ecológico retrospectivo para observar a distribuição espacial e temporal de casos confirmados da leptospirose em escala nacional no período entre 2007 e 2017. A espacialização da leptospirose utilizou técnicas de geoprocessamento por análise de padrões pontuais e por mapas de densidade Kernel. Os resultados revelaram que, no período, foram registrados 42.310 casos confirmados de leptospirose no País, com média anual de 3.846 casos e prevalência de 1,9 a cada 100 mil habitantes. As localidades com mais casos prevalentes foram as regiões Sul e Norte. O Sudeste apresentou taxa de prevalência inferior à taxa nacional em virtude da alta densidade demográfica. O método Kernel se mostrou útil na análise global da situação epidemiológica da leptospirose nas regiões do Brasil.

The Environmental Protection Area (EPA) of Banhado Grande, located in the Metropolitan Region of Porto Alegre, comprises three areas of marshes, the Banhado Chico Lomã, the Banhado Grande and Banhado dos Pachecos. In periods of large flood pulses extensive flooded areas are formed between these wetlands and the river Gravataí floodplain, establishing a connectivity between the Wetlands of EPABG. This connectivity indicates that there is an interaction between these wetlands, such as exchange of nutrients, sediments and living organisms. Thus, this study aims to map extensive floodable areas associated with large flood pulses and to analyze the connectivity areas in EPABG. For this, the work is structured in three steps: i) choice of satellite images between the years 2000 to 2015 to identify largest flood pulses; ii) mapping of floodable areas in large flood pulses using images Normalized Difference Index Water (NDWI); and iii) analysis of the connectivity among wetlands. As the results, in large flood pulses, with precipitation greater than 247 mm, in the 30 days prior to the date of the image, establishing a large area of connectivity between the wetlands, forming on the polygon defined by elevation of 11 metres, two types of connectivity: wetlands-wetlands connectivity, allowing interactions among environments with turf and lagoon deposits; and wetlands-stream connectivity, linking the alluvial and floodplain of the Gravataí River deposits with the background lagoon and paludals deposits. Already, in flood pulses of flooding with rainfall less than or equal to 200 mm, in the last 30 days, the flooded area appears fragmented inside the polygon associated at an elevation of 11 metres, mainly in the corridor between the marshes Grande and the Pachecos, that does not connect by flood, forming just wetlands-stream connectivity. Thus, the characterization of the flood pulses and connectivity become fundamental to the understanding of the dynamic of wetlands, because, make aware of for the need to preserve these areas of importance for flood control, microclimate regulation and maintenance of biodiversity.

Fires are one of the main factors for disturbances in Niassa Reserve-Mozambique, with economic and environmental impacts. There are cyclical records of fire occurrences across the reserve. However, studies on the main causative factors and identification of more susceptible locations are very limited. In this perspective, this study had as objectives: (1) determine the main significant factors for wildfire occurrences; (2) Map the probability of wildfire occurrences, using logistic regression. Independent variables included vegetation index (NDVI), climatic, topographic and socioeconomic data. The analysis period was from 2001 to 2015 and comprised the months with more occurrences of wildfire (May to December). According to the results, the main factors that determine the occurrence of fires were: NDVI, temperature, elevation, followed by precipitation, slope, relative humidity and human settlements. The spatial distribution of probability of fire occurrence reveals that zones with high and very high risk are located at the west and central west zones (areas with higher accumulation of dry biomass); medium risk zones are located in the centre of the reserve, while in central east and east zones the probability of fire occurrence is low and very low risk. Results showed that the expectation of wildfire ignition using logistic regression presented good precision (area under the curve 74%).

Wildfires are among the biggest factors of ecosystem change. Knowledge of fire regime 12 (fire frequency, severity, intensity, seasonality, and distribution pattern) is an important factor in 13 wildfire management. This paper aims to analyze the spatiotemporal patterns of fires and burned 14 areas in the Niassa Reserve between 2002-2015 using MODIS data, active fire product (MCD14ML) 15 and burned area product (MCD64A1). For this, the annual and monthly frequencies, the trend of 16 fires and the frequency by types of forest cover were statistically analyzed. For the analysis of the 17 spatial dynamics of forest fires we used the Kernel density (Fixed Method). The results show a 18 total of 20.449 forest fires and 171.067 km² of burned areas in the period 2002-2015. Fire incidents 19 were highest in 2015, while the largest burned areas were recorded in 2007. The relationship 20between increased fires and burned areas is not linear. There was a tendency for fires to increase, 21 while for burnt areas there was stabilization. Forest fires start in May and end in December. 22August-October are the most frequent period, peaking in September. Fires occur predominantly 23 in deciduous forests and mountain forests because of the type of vegetation and the amount of dry 24 biomass. There is a monthly spatial dynamics of wildfires from east to west in the reserve. This 25 behavior is dependent on vegetation cover type, fuel availability, and senescence. 26

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