摘要
根据黑龙江省 1980～ 1999年的林火资料 ,利用地理信息系统等工具 ,对黑龙江省林火时空动态和分布规律进行了研究。结果表明 ,黑龙江省林火可分为 1980～ 1987年的多发段和 1988年以后的低发段。人为火与总林火规律相似 :次数频谱周期为 16、4 5a和 2 3a ,面积频谱周期为 6a。雷击火次数频谱周期为 9 1a和 3 0a左右 ,面积频谱周期为 9 1a。总林火次数和面积显著正相关 ,雷击火的次数与面积不相关。林火主要发生在 4月、5月。人为火面积集中在 3月、4月 ,雷击火面积集中在 5月。林火由西北向东南呈条带状分布 ,西部、西南部和东北部林火较少。有 5个林火多发区。林火面积、平均蔓延速率、持续时间呈对数正态分布 ,具有自组织特点 ,分数维分别是 0 86、1 0 5和 0 6 8。对火频谱周期、自组织性进行了讨论 ,指出自组织函数将林火的时空特性结合在一起 ,采用负幂函数描述时存在适用下限并给出计算公式。对不同区域的自组织分数维进行了比较。
The spatial and temporal dynamics and statistical distribution of forest fires in Heilongjiang province was studied here based on fire data of the province during 1980～1999 by means of GIS software. The results showed that the 20 years fire history can be divided into two phases: low fire occurrence stage before 1987 and high fire occurrence stage after 1987 The annual fire number and anthropogenic fire number are positively correlated with similar spectrum cycles of 2 3, 4 6 and 16 years and a size spectrum cycle of 6 years. Annual areas burned by lightning caused fires is irrelevant to its number, the former cycles every 9 1 years and the later every 9 1 and 3 0 years in each spectrum. Fires occur mainly in April and May with more burned areas in March and April for anthropogenic fires and May for lightning caused ones. The fires spatially distributed as a belt from northwest to southeast with 5 high fire occurrence regions and few burns in the west, southwest and northeast parts of the province. The fire size, averaged area expanding rate and burning time follow lognormal distribution with a self organizing character with respective fractal dimensions of 0 86、1 045 and 0 68 Discussion is made on fire cycles, self organizing characters and suitable frequency and intensity of human introduced fires in ecosystems. It is emphasized that although self organizing function links the spatial characters of fire with temporal ones, a lower limit exits when describing self organizing character with negative power functions and a formula for calculating the limit is presented here. Comparison is also made between fire fractals of different regions.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2002年第1期88-94,共7页
Scientia Silvae Sinicae
基金
国家自然科学基金面上项目 3 9870 63 6
国家自然科学基金青年基金项目 3 0 0 0 0 13 5
国家自然科学基金重大项目 3 98993 70资助
关键词
林火规律
时空分布
自组织
火频度
时空动态
黑龙江
Forest fire, Spatial and temporal dynamics, Self organizing, Fire frequency
