为建立适用于我国宏观区域的林火预警系统,以我国2000-2008年间发生的重大森林火灾为研究对象,利用MODIS数据估算森林可燃物的长势及含水量,与地理信息系统技术和数据库技术相结合,以火险指数作为预报林火发生等级的定量因子,研究并建...为建立适用于我国宏观区域的林火预警系统,以我国2000-2008年间发生的重大森林火灾为研究对象,利用MODIS数据估算森林可燃物的长势及含水量,与地理信息系统技术和数据库技术相结合,以火险指数作为预报林火发生等级的定量因子,研究并建立了林火预警模型;在商业遥感和GIS软件提供的二次开发平台下,利用Microsoft Visual Studio 2005语言,开发了林火预警系统。同时,利用选取的实验区及数据对预报方法和系统进行测试。结果表明:利用建立的林火预警系统所得的森林火险等级值,与实际发生的林火趋势基本一致;另外,火险指数可用作林火发生预警的定量分级因子。展开更多
基于森林火灾统计资料,采用加拿大森林火险天气指标系统(Canadian Forest Fire Weather Index System,CFFWIS)分析了浙江省森林火险期内森林火险天气指标动态变化趋势。结果表明:研究区火险期内森林火灾发生次数呈递减趋势,但每场火灾...基于森林火灾统计资料,采用加拿大森林火险天气指标系统(Canadian Forest Fire Weather Index System,CFFWIS)分析了浙江省森林火险期内森林火险天气指标动态变化趋势。结果表明:研究区火险期内森林火灾发生次数呈递减趋势,但每场火灾的平均过火面积呈显著增加趋势(P<0.01);细小可燃物湿度码(CFFM)和初始蔓延指标(IIS)达到显著水平(P<0.05),可作为浙江省森林火险期火险状况的良好指标;1991-2011年,研究区森林防火期内可燃物湿度指标、火行为指标及火灾控制难易度指标总体呈增加趋势。其中,春季火险期可燃物干燥状况增加趋势较秋、冬季火险期幅度大,且已达到显著水平(P<0.05)。因此,加大该区的森林火灾防控工作,尤其是春季火险期的防控工作刻不容缓。展开更多
Forest fire is one of the main natural hazards because of its fierce destructiveness. Various researches on fire real time monitoring, behavior simulation and loss assessment have been carried out in many countries. A...Forest fire is one of the main natural hazards because of its fierce destructiveness. Various researches on fire real time monitoring, behavior simulation and loss assessment have been carried out in many countries. As fire prevention is probably the most efficient means for protecting forests, suitable methods should be developed for estimating the fire danger. Fire danger is composed of ecological, human and climatic factors. Therefore, the systematic analysis of the factors including forest characteristics, meteorological status, topographic condition causing forest fire is made in this paper at first. The relationships between biophysical factors and fire danger are paid more attention to. Then the parameters derived from remote sensing data are used to estimate the fire danger variables, According to the analysis, not only PVI (Perpendicular Vegetation Index) can classify different vegetation but also crown density is captured with PVI. Vegetation moisture content has high correlation with the ratio of actual evapotranspiration (LE) to potential ecapotranspiration (LEp). SI (Structural Index), which is the combination of TM band 4 and 5 data, is a good indicator of forest age. Finally, a fire danger prediction model, in which relative importance of each fire factor is taken into account, is built based on GIS.展开更多
文摘为建立适用于我国宏观区域的林火预警系统,以我国2000-2008年间发生的重大森林火灾为研究对象,利用MODIS数据估算森林可燃物的长势及含水量,与地理信息系统技术和数据库技术相结合,以火险指数作为预报林火发生等级的定量因子,研究并建立了林火预警模型;在商业遥感和GIS软件提供的二次开发平台下,利用Microsoft Visual Studio 2005语言,开发了林火预警系统。同时,利用选取的实验区及数据对预报方法和系统进行测试。结果表明:利用建立的林火预警系统所得的森林火险等级值,与实际发生的林火趋势基本一致;另外,火险指数可用作林火发生预警的定量分级因子。
文摘基于森林火灾统计资料,采用加拿大森林火险天气指标系统(Canadian Forest Fire Weather Index System,CFFWIS)分析了浙江省森林火险期内森林火险天气指标动态变化趋势。结果表明:研究区火险期内森林火灾发生次数呈递减趋势,但每场火灾的平均过火面积呈显著增加趋势(P<0.01);细小可燃物湿度码(CFFM)和初始蔓延指标(IIS)达到显著水平(P<0.05),可作为浙江省森林火险期火险状况的良好指标;1991-2011年,研究区森林防火期内可燃物湿度指标、火行为指标及火灾控制难易度指标总体呈增加趋势。其中,春季火险期可燃物干燥状况增加趋势较秋、冬季火险期幅度大,且已达到显著水平(P<0.05)。因此,加大该区的森林火灾防控工作,尤其是春季火险期的防控工作刻不容缓。
文摘Forest fire is one of the main natural hazards because of its fierce destructiveness. Various researches on fire real time monitoring, behavior simulation and loss assessment have been carried out in many countries. As fire prevention is probably the most efficient means for protecting forests, suitable methods should be developed for estimating the fire danger. Fire danger is composed of ecological, human and climatic factors. Therefore, the systematic analysis of the factors including forest characteristics, meteorological status, topographic condition causing forest fire is made in this paper at first. The relationships between biophysical factors and fire danger are paid more attention to. Then the parameters derived from remote sensing data are used to estimate the fire danger variables, According to the analysis, not only PVI (Perpendicular Vegetation Index) can classify different vegetation but also crown density is captured with PVI. Vegetation moisture content has high correlation with the ratio of actual evapotranspiration (LE) to potential ecapotranspiration (LEp). SI (Structural Index), which is the combination of TM band 4 and 5 data, is a good indicator of forest age. Finally, a fire danger prediction model, in which relative importance of each fire factor is taken into account, is built based on GIS.
