Fillipe Tamiozzo Pereira Torres

Mapeamento da suscetibilidade a ocorrências de incêndios em vegetação na área urbana de Ubá-MG

3RESUMO – O fogo e problema crescente nos diferentes tipos de formacao vegetal em diversas partes do mundo. Apesar de anos de estudo cientifico e de toda atencao da midia em relacao aos incendios em vegetacao, os efeitos que tais fenomenos causam no ambiente nao sao completamente conhecidos, e as ferramentas de controle sao pouco acessiveis a grande parte dos usuarios. E fundamental saber o que condiciona as ocorrencias, o que favorece a dispersao do fogo e o padrao de tais ocorrencias, para possibilitar o mapeamento das areas de risco e permitir o desenvolvimento de programas especificos para as regioes criticas. O objetivo deste estudo foi produzir um mapa de suscetibilidade a incendios em vegetacao, dentro do perimetro urbano do Municipio de Uba, MG, com a utilizacao de informacoes referentes ao relevo, ao uso e cobertura do solo e a proximidade de vias de acesso e areas urbanas, empregando tecnicas de Geoprocessamento. A partir da validacao do cartograma gerado, observou-se que 80% das ocorrencias tem-se localizado nas areas de alto e altissimo risco, 15% nas de medio risco e 5% nas areas de baixo e baixissimo risco. Esse mapeamento servira como ferramenta para o poder publico estabelecer politicas de prevencao, atuando na conscientizacao da populacao e na definicao de medidas de controle nas areas de maior risco. Palavras-chave: Incendios em vegetacao; Suscetibilidade; Mapa. SUSCEPTIBILITY MAPPING OF THE OCCURRENCE OF VEGETATION FIRE IN THE URBAN AREA OF UBA - MG

Determinação do período mais propício às ocorrências de incêndios em vegetação na área urbana de Juiz de Fora, MG

Resumo – Os incendios em vegetacao podem provocar severos danos ao ambiente, alem de consequencias economicas consideraveis, como a destruicao de habitats, a queima de madeira e os custos para o seu combate. Para estabelecer politicas de controle e prevencao, faz-se necessario conhecer o perfil dos incendios. As estatisticas de ocorrencia dos incendios em vegetacao sao as principais ferramentas para se tracar seu perfil. Com esses dados, pode-se planejar o controle de modo mais eficiente, diminuindo gastos, tempo e riscos em seu combate. O objetivo deste estudo visou a determinacao da epoca do ano e horario de maiores ocorrencias de incendios em vegetacao no Municipio de Juiz de Fora, MG. Para isso, foi utilizada uma serie temporal de 10 anos (1995 - 2004), com dados de ocorrencias de incendios e elementos climaticos na area urbana do municipio. De acordo com os resultados, foi caracterizado o periodo de junho a outubro como a estacao normal do fogo. Em relacao as horas do dia, o periodo das 10 as 20 h foi o que concentrou o maior numero de ocorrencias, tendo seu pico entre 15 e 16 h. Palavras-chave: Fogo, Horario e Epoca do ano.

Correlações entre os elementos meteorológicos e as ocorrências de incêndios florestais na área urbana de Juiz de Fora, MG

Forest fires in Brazil become more critical every year, with the increase of the extension of burned areas and the consequent damages to the atmosphere and society. The occurrence and propagation of forest fires are strongly associated with climatic factors or conditions. Among the influences that the climate can exercise on the occurrences is the distribution of dead vegetation humidity, which constitutes the main fuel of fires. The objective of this study was to compare the correlation index between the meteorological factors and the occurrences of forest fires in the urban area of the district of Juiz de Fora. To accomplish the study, a temporary series was used, including the period from 1995 to 2004. According to the results, the relative humidity of the air was the element that showed most correlation with the occurrences. The precipitation and the difference between precipitation and evaporation showed more correlation with the fires when analyzing its accumulation within the period of 10 days before each occurrence. The use of isolated elements presented a low correlation with the fires, suggesting the use of models containing climatic elements for the prediction of the occurrences.

Relações entre incêndios em vegetação e elementos meteorológicos na cidade de Juiz de Fora, MG

Vegetation fires generate several economical, landscaping and ecological damages. However, it is necessary to know the fires occurrence statistics in order to establish an appropriate politics of fire prevention and control. The objective of this paper is to analyze the influence of climatic elements on the occurrences of fires in Juiz de Fora (MG), in the period between 1995 and 2004. For that purpose, the correlation between some isolated meteorological elements and the occurrences of fires were analyzed, as well as the efficiency of some predicting indexes found in the literature. According to the results, the relative air humidity measured at 3:00 p.m. presented the greatest correlation value; however it was verified that the use of a single variable presented a low correlation index with the fire occurrences, emphasizing the importance of using models containing two or more variables. The use of such models showed that the rate of the variables, evaporation and accumulated precipitation, was the most efficient index for the study area.

ANALYSIS OF EFFICIENCY OF FIRE DANGER INDICES IN FOREST FIRE PREDICTION

http://dx.doi.org/10.1590/1806-90882017000200009 ABSTRACT – Despite the existence of different fire danger indices, the use of an inefficient index can lead to making wrong decisions on the appropriate procedures for preventing and fighting forest fires, while a trusted prediction index can help the most quantification and allocation of resources for prevention. Thereat, the objective of this study is to analyze the efficiency of Fire Weather Index (FWI), Logarithmic of Telicyn Index, Nesterov Index, cumulative indexes of precipitation evaporation (P-EVAP) and evaporation / precipitation (EVAP/P), Monte Alegre Index (FMA) and Monte Alegre Changed Index (FMA) in the prediction of forest fires for the city of Viçosa (MG). The indices were compared using the method known as Skill Score (SS) taking into account the days that the indexes pointed to the risk of events with focus fire identified by satellite images on the 01/01/2005 to 31/12/2014 period. According to the results, the Logarithm of Telicyn Index (0.53257) as the most efficient for the study area, followed by the indices EVAP/P (0.46553), P-EVAP (0.43724), Nesterov (0.40445), FWI (0.39213), FMA (0.34595) and FMA (0.28982).

RISK MAPPING OF FIRES IN VEGETATION IN THE SERRA DO BRIGADEIRO STATE PARK (MG) AND SURROUNDINGS

1 Received on 25.05.2016 accepted for publication on 16.03.2017. 2 Universidade Federal de Viçosa, Departamento de Engenharia Florestal, Viçosa, MG, Brasil. E-mail: <tamiozzo@ufv.br>, <gslima@ufv.br>, <venancio@ufv.br> and <valverde@ufv.br>. 3 Universidade Federal de Viçosa, Graduado em Geografia, MG, Brasil. E-mail: <rafael.geo.siqueira@gmail.com>. 4 Instituto Estadual de Florestas Centro de Estudos e Desenvolvimento Florestal, Viçosa, MG, Brasil. E-mail: <cedef.ief@gmail.com>. *Corresponding author.

Wildfires as a major challenge for natural regeneration in Atlantic Forest

The natural regeneration management is a good strategy of ecological restoration of the Atlantic Forest, one of the most devastated biomes on the planet. However, the frequent occurrence of wildfires is one of the challenges to the success of this method. The objective of this study was to evaluate the effects of wildfires on forest dynamics in Atlantic Forest. The studied area was explored during the coffee cycle when plantations replaced primary forests. We used remote sensing data to analyze the forest dynamics over a period of 50 years (1966-2016). We used the INPE burn database to find the occurrence of hot spots from 1998 to 2016. During this period, we selected the years most affected by the fires for the identification of fire scars using the Normalized Burn Ratio spectral index. From this set of information, we used the methodology of weights of evidence to relate forest dynamics and wildfire events with biophysical and anthropic variables. The results showed that in 1966 the forest area accounted for 8.01% of the land cover, and in 2016 this number rose to 18.55% due to the spontaneous natural regeneration process. The regenerating areas were mainly related to the proximity of the remaining fragments and the portions of the landscape receiving the least amount of global solar radiation. The proximity to urban areas, roads and highways, damaged regeneration and favored both deforestation and wildfire events. Fire scars preferentially occur where there is greater sun exposure. It is possible to observe a negative correlation between the natural regeneration process and the fire scars. We concluded that fire severity is one of the factors that shape the landscape of the region while slowing the regeneration process in preferential areas.

Potentials and limitations of remote fire monitoring in protected areas

Protected areas (PAs) play an important role in maintaining the biodiversity and ecological processes of the site. One of the greatest challenges for the PA management in several biomes in the world is wildfires. The objective of this work was to evaluate the potentialities and limitations of the use of data obtained by orbital remote sensing in the monitoring fire occurrence in PAs. Fire Occurrence Records (FORs) were analyzed in Serra do Brigadeiro State Park, Minas Gerais, Brazil, from 2007 to 2015, using photo interpreted data from TM, ETM+ and OLI sensors of the Landsat series and the Hot Spot Database (HSD) from the Brazilian Institute of Space Research - INPE. It was also observed the time of permanence of the scar left by fire on the landscape, through the multitemporal analysis of the behavior of NDVI (Normalized Difference Vegetation Index) and NBR (Normalized Burn Ratio) indexes, before and after the occurrence. The greatest limitation found for the orbital remote monitoring was the presence of clouds in the passage of the sensor in dates close to the occurrence of the fires. The burned area identified by photo interpretation was 54.9% less than the area contained in the FOR. Although the HSD reported fire occurrences in the buffer zone (up to 10km from the Park), no FORs were found at a distance greater than 1100m from the boundaries of the PA. As the main potential of remote sensing, the possibility of identifying burned areas throughout the park and surroundings is highlighted, with low costs and greater accuracy.

Fire danger index efficiency as a function of fuel moisture and fire behavior

Assessment of the performance of forest fire hazard indices is important for prevention and management strategies, such as planning prescribed burnings, public notifications and firefighting resource allocation. The objective of this study was to evaluate the performance of fire hazard indices considering fire behavior variables and susceptibility expressed by the moisture of combustible material. Controlled burns were carried out at different times and information related to meteorological conditions, characteristics of combustible material and fire behavior variables were recorded. All variables analyzed (fire behavior and fuel moisture content) can be explained by the prediction indices. The Brazilian EVAP/P showed the best performance, both at predicting moisture content of the fuel material and fire behavior variables, and the Canadian system showed the best performance to predicting the rate of spread. The coherence of the correlations between the indices and the variables analyzed makes the methodology, which can be applied anywhere, important for decision-making in regions with no records or with only unreliable forest fire data.

FIRE BEHAVIOR VARIABLES AND HAZARD INDICES OF FOREST FIRES

http://dx.doi.org/10.1590/1806-90882018000300006 ABSTRACT – The objective of this study was to evaluate the performance of different fire hazard indices (FWI, FMA, FMA+, Telicyn, Nesterov, P-EVAP and EVAP/P), taking into account the fire behavior variables and the susceptibility to fire expressed by the moisture of the combustible material. For this purpose, controlled burnings were performed at different times and information was recorded in relation to the meteorological conditions, characteristics of the combustible material and fire behavior variables. In general, all the indices presented significant correlations with both the moisture of the combustible material and the behavior of the fire. However, in general, a higher linear correlation of components of the Canadian Fire Weather Index (FWI) system was observed in predicting fire behavior and EVAP / P index in fuel moisture. The consistency of the correlations between the various indices and the analyzed variables makes the methodology possible to be used in any place, facilitating the decision making in regions where records of occurrences of forest fires are absent or unreliable.