浙江省森林火灾时空特征及其与气象因子的关系

Temporal and spatial pattern of forest fire in Zhejiang and its relationship with meteorological factors

利用2010—2017年的逐日气象数据和浙江省森林火灾数据,选择其中1263次森林火灾事件,对发生森林火灾站点的各个气象要素进行合成分析,研究了浙江省森林火灾在时间演变和空间分布上的特征及其与气象因子之间的联系。结果表明,在时间上,浙江省森林火灾主要发生在1-4月,发生频次和过火面积均随时间呈振荡下降趋势,其中2011年发生森林火灾频次最多,为433次,火场总面积4708 hm^(2),烧荒烧炭(457次)和上坟烧纸(502次)是浙江省森林火灾发生的主要原因;在空间上,温州、丽水、台州的森林火灾发生频次最高。森林火灾发生与日降水量、相对湿度呈反相关,与日最高气温、风速、轻旱或无旱条件下的连续无降水日数呈正相关。进一步分析表明,连续无降水日数对应函数值对森林火险气象指数贡献最大。

Based on the data of forest fires and daily meteorological statistics during 20102017 in Zhejiang province,choosing 1263 forest fire events,and to propose analysis-by-synthesis approach for study on the temporal and spatial pattern of the forest fires and relationship between each meteorological element with forest fire events,the results show that in terms of time,forest fires mainly occurred in Zhejiang province from January to April,and the frequency and area of fire showed an oscillating downward trend.Among them,forest fires occurred most frequently in 2011,433 times,with a total fre area of 4708 hm^(2).The fires that occurred in Zhejiang province were dominated by larger fires.The main causes of forest fire were farming burning(457 times)and sacrificial burning(502 times).On the spatial distribution,occurrence of forest fire appears most frequently in Wenzhou,Lishui and Taizhou.The occurrence of forest fires is inversely correlated with daily precipitation and relative humidity,and positively correlated with temperature,wind speed and the number of consecutive precipitation-free-day under the condition of light drought.Further analysis shows that the number of consecutive precipitation-free-day contributes most to the index of forest fire danger during forest fire events in Zhejiang province.