Burned area mapping is an essential step in the forest fire research to investigate the relationship between forest fire and cli- mate change and the effect of forest fire on carbon budgets. This study proposed an alg...Burned area mapping is an essential step in the forest fire research to investigate the relationship between forest fire and cli- mate change and the effect of forest fire on carbon budgets. This study proposed an algorithm to map forest fire burned area using the Moderate-Resolution Imaging Spectroradiameter （MODIS） time series data in Heilongjiang Province, China. The algorithm is divided into two steps： Firstly, the ＇core＇ pixels were extracted to represent the most possible burned pixels based on the comparison of the tem- poral change of Global Environmental Monitoring Index （GEMI）, Burned Area Index （BAI） and MODIS active fire products between pre- and post-fires. Secondly, a 15-km distance was set to extract the entire burned areas near the ＇core＇ pixels as more relaxed conditions were used to identify the fire pixels for reducing the omission error as much as possible. The algorithm comprehensively considered the thermal characteristics and the spectral change between pre- and post-fires, which are represented by the MODIS fire products and the spectral index, respectively. Tahe, Mohe and Huma counties of Heilongjiang Province, China were chosen as the study area for burned area mapping and a time series of burned maps were produced from 2000 to 2011. The results show that the algorithm can extract burned areas more accurately with the hiehest accuracy of 96.61%.展开更多
This paper presents an analysis of the fire trends in southern European countries, where forest fires are a major hazard. Data on number of fires and burned area size from 1985 until 2009 were retrieved from the Europ...This paper presents an analysis of the fire trends in southern European countries, where forest fires are a major hazard. Data on number of fires and burned area size from 1985 until 2009 were retrieved from the European Fire Database in the European Forest Fire Information System and used to study the temporal and spatial variability of fire occurrence at three different spatial scales： the whole European Mediterranean region, country level and province level （NUTS3）. The temporal trends were assessed with the Mann-Kendall test and Sen＇s slope in the period 1985-2009. At regional （supranational） level, our results suggest a significant decreasing trend in the burned area for the whole study period. At country level, the trends vary by country, although there is a general increase in number of fires, mainly in Portugal, and a decrease in bumed areas, as is the case of Spain. A similar behavior was found at NUTS3 level, with an increase of number of fires in the Spanish and Portuguese provinces and a generalized decrease of the burned area in most provinces of the region. These results provide an important insight into the spatial distribution and temporal evolution of fires, a crucial step to investigate the underlying causes and impacts of fire occurrence in this region.展开更多
基金Under the auspices of Strategic Pilot Science and Technology Projects of Chinese Academic Sciences(No.XDA05090310)
文摘Burned area mapping is an essential step in the forest fire research to investigate the relationship between forest fire and cli- mate change and the effect of forest fire on carbon budgets. This study proposed an algorithm to map forest fire burned area using the Moderate-Resolution Imaging Spectroradiameter （MODIS） time series data in Heilongjiang Province, China. The algorithm is divided into two steps： Firstly, the ＇core＇ pixels were extracted to represent the most possible burned pixels based on the comparison of the tem- poral change of Global Environmental Monitoring Index （GEMI）, Burned Area Index （BAI） and MODIS active fire products between pre- and post-fires. Secondly, a 15-km distance was set to extract the entire burned areas near the ＇core＇ pixels as more relaxed conditions were used to identify the fire pixels for reducing the omission error as much as possible. The algorithm comprehensively considered the thermal characteristics and the spectral change between pre- and post-fires, which are represented by the MODIS fire products and the spectral index, respectively. Tahe, Mohe and Huma counties of Heilongjiang Province, China were chosen as the study area for burned area mapping and a time series of burned maps were produced from 2000 to 2011. The results show that the algorithm can extract burned areas more accurately with the hiehest accuracy of 96.61%.
文摘This paper presents an analysis of the fire trends in southern European countries, where forest fires are a major hazard. Data on number of fires and burned area size from 1985 until 2009 were retrieved from the European Fire Database in the European Forest Fire Information System and used to study the temporal and spatial variability of fire occurrence at three different spatial scales： the whole European Mediterranean region, country level and province level （NUTS3）. The temporal trends were assessed with the Mann-Kendall test and Sen＇s slope in the period 1985-2009. At regional （supranational） level, our results suggest a significant decreasing trend in the burned area for the whole study period. At country level, the trends vary by country, although there is a general increase in number of fires, mainly in Portugal, and a decrease in bumed areas, as is the case of Spain. A similar behavior was found at NUTS3 level, with an increase of number of fires in the Spanish and Portuguese provinces and a generalized decrease of the burned area in most provinces of the region. These results provide an important insight into the spatial distribution and temporal evolution of fires, a crucial step to investigate the underlying causes and impacts of fire occurrence in this region.
