基于RS和GIS的庐山森林火险区划研究

A Study of Forest Fire Danger District Division in Lushan Mountain Based on RS and GIS

依据庐山历史森林火灾特点,选取防火期平均最高气温、平均气温、平均降水量、平均最长连旱天数、平均风速、植被类型、海拔、坡度和坡向9个因子作为森林火险区划指标,并按照各区划因子对林火的灵敏度或其对成火的影响分别被赋予不同的权重。通过采用RS和GIS技术,利用Landsat TM影像提取植被信息图层;再利用地形图扫描数字化生成1∶5万的数字高程模型(DEM),一方面提取有关地形信息(海拔、坡度、坡向),另一方面结合庐山及周边7个气象站气候资料建立的气候资源数据库和地理推算模型,采用小网格推算方法进行整体插值,生成气候资源分布图;最后采用因子加权叠置法整合所有单因子专题图,生成综合区划图,并将研究区划分为特级、Ⅰ级、Ⅱ级3个森林火险区。

The study selected 9 factors （average maximum temperature, average temperature, average precipitation, average the longest days of continuous drought and average wind speed during fire prevention period,vegetation type, altitude,slope and aspect） as the index of forest fire danger district division,which has taken the features of Lushan Mountain＇ s forest fire history into consideration, then assigned subjective weights to each factor according to their sensitivity to fire or their fire - inducing capability. By RS and GIS, the vegetation info. layers were gotten from Landsat TM image and DEM with a scale of 1 ： 50000 was abstracted from the digital scanned relief map. Topography info. （elevation, slope, aspect） layers could be gotten after that. A climate resource databank that contained the data from the stations of Lushan Mountain and other nearby 7 stations was built up and extrapolated through the way of grid extrapolation in order to make the distribution map of climate resources. Finally the synthetical district division maps were made by weighing and integrating all the single factor special layers, and the study area were divided into three forest fire danger districts, include special fire danger district, Ⅰ - fire danger district and Ⅱ - fire danger district. It could be used as a basis for developing a forest fire prevention system, preparing the annual investment plan, allocating reasonably the investment of fire prevention, developing the program of forest fire prevention and handle, setting up forest fire brigade , leaders＇ decisions on forest fire prevention work