森林火灾是林火失去人为控制,在森林内自然蔓延和扩展,对生态系统和人类带来一定危害和损失的森林起火。森林火灾属世界性、跨国性的重大自然灾害,进入20世纪80—90年代以来,全球气候变暖导致森林火灾有上升的趋势,虽然各国的森林防火费用不断增加,但森林火灾发生的面积并未相应地减少。特别是90年代后期,火灾毁灭了数百万公顷的热带森林,严重破坏了全球的生态平衡。
Information on spatial and temporal patterns of forest fires contributes to effective fire management.Based on data of the forest fires occurred in Heilongjiang Province from 1980 to 2005,the spatial and temporal distribution of forest fires was studied by using of statistical analysis and spatial analysis method.The results indicated that forest fires fluctuated obviously year to year.The burned area was somewhat correlated with the total number of fires.The number of spring fires and the burned area contributed 72.52% and 84.39% to the total fires and area,respectively.The number of summer fires and the burned area were relatively less and smaller.Fall had a short fire season.Heihe city had the greatest number of forest fires and the Daxing'an Mountains region had the largest burned area in the 13 administrative regions studied.The Daxing'an Mountains had the highest fire frequency and the largest burned area over the 5 landscape areas,and its fire burned area accounted for 89.42% of the total.The fire frequency showed a reducing trend with altitude rise in the mountainous areas.The forest fire occurrence and the spatial and temporal variation are useful information for classing the forest fire danger rank and forecasting forest fires,and the information would have important theoretical and practical significance for efficient management in forest fire fighting and prevention.