云南松林凋落物表层细小可燃物含水率预测模型研建

Modeling on Moisture Content Predicting of Surface Fine Fuel of Litter-fall Layer in Pinus yunnaneneis Stands

在2008年防火期2-5级火险天气条件下，在云南松纯林测定了137组林内气温（X1）、相对湿度（X2）、凋落物层表面温度（x3）、腐殖质层表面温度（x4）、凋落物层厚度（x5）、凋落物表层细小可燃物含水率（y）数据。分析表明，影响云南松林凋落物上层细小可燃物含水率的因子依次为：X3〉X2〉X4〉X1，凋落物层厚度与含水率相关性很小，可以不参与模型的建立。用多元回归方法建立了云南松林细小可燃物含水率预测模型。新落叶的含水率对火环境因子的响应滞后是造成模型误差的主要原因。

The study tested 137 groups of air temperature （x1）, relative humidity （x2）, surface temperature of litter layer （x3）, surface temperature of humic substances layer（x4）, thickness of litter-fall layer（x5）and moisture content of surface fine fuel of littler-fall layer（y）in pure Pinus yunnaneneis stands in 2-5 weather grade in forest fire-danger in forest tire season in 2008. The results showed that the main factors influenced the moisture content of surface fine fuel were arranged in order of x3〉x2〉x4〉x1 ,and thickness of litter layer was not used to construct regression model because it had little correlation coefficients. The model was established by the multivariate linear regression. Response of fuel moisture change to fire environment lagged was the main reason why the model had error.