森林可燃物含水率与气象条件相关性的初步研究

THE RELATIONS BETWEEN WATER CONTENT RATIO OF FOREST COMBUSTIBLE MATERIALS AND METEOROLOGICAL CONDITIONS

本文通过对昆明地区云南松林内旱季小气候要素(气温、地温、最高温度、最低温度、相对湿度、风速和土壤含水率)与林内五种可燃物(枯枝落叶、腐殖质、活地被物、下木和林冠枝叶)含水率的相关关系,利用计算机对观测的数据资料进行多元回归分析,筛选出每种可燃物所对应的主要相关气候因子,为建立预报方程、提供了研究依据,并分析这些主要相关气候因子时可燃物含水率的作用机制,揭示林区环境与林火的基本关系,根据土壤含水率、地温、气温、相对湿度,初步确定出观测林区及其类似林林分的火险等级和各级火险期。

By making parallel observations on the microclimate factors (including air and ground temperatures, the highest and lowest temperatures, relative humidity, wind speed and soil moisture) and the water content ratios of 5 combustible materials (i. e. litter, humus, green cover, shrub, and branches and leaves on the canopy) in Yunnan pine (Pinus yunnanensis Franch.) forests in Kunming area during dry seasons, the authors analyzed the correlativity of the microcli- mate factors acting on the water content ratios of the 5 combustible materials. After the observed data were treated on a computer by means of multivariate regression analyses, 4 major microclimate factors corresponding to each com- bustible material were analyzed and screened so that the scientific basis of this study was provided to establish the equation for the forecast of forest fires. Based on the 4 factors-soil moisture, air temperature, ground temperature and relative humidity, which effect the water content ratios of the forest com- bustible materials significantly and reveal the basic relations between the forest environment and forest fires, fire hazard periods and various classes of fires for Yunnan pine forests and similar stands have been decided preliminarily.