可燃物干燥指数在草地火险预警中的应用

Application of fuel dry index in the prairie fire danger

在草地生物物理特性基础上,结合能量交换原则(由遥感和气象数据得到显热和潜热通量)提出了可燃物干燥指数( Fd ),并将其应用于山东省草地火险监测。 Fd 较好解决了山东省草地火灾风险预警时空预测问题,提高了火险的估算精度,能够随时间变化动态预警山东省每日高火灾风险区域。将 Fd 与美国潜在火险模型(fire potential index,FPI)用于2010年4月8日的火险预警研究,结果表明 Fd 较 FPI 能够更好地指示火险。在等间距火险分类法中,2010年31个火点数据 Fd 值在Ⅲ级以上的占87.1%,Ⅰ级为0,火灾发生地点与火灾风险预警高的区域吻合较好。由 Fd 曲线图可以看出 Fd 与草地植被生长季节有着紧密的关系,初期和发育期的 Fd 值较高,但呈下降趋势;中期 Fd 值低;晚期 Fd 值高,并呈现上升趋势。总体说明了 Fd 指数在草地生长阶段火险预报中的重要作用。

In this paper,on the basis of prairie biophysical characteristics and in combination with the principle of energy exchange (sensible heat and latent heat flux obtained by remote sensing and meteorological data),the fuel dry index ( Fd ) was proposed and applied to the Shandong prairie fire monitoring.Fd can better solve the prairie fire forecast,fire danger early warning in time and space and the estimation accuracy.It can change dynamic warning daily high fire risk areas with time in Shandong Province.Fd and fire potential index (FPI) were used to study the fire danger on April 8,2010.Fire indicating effect of Fd is better than that of FPI.In the equidistance fire classification,data of 31 fire points in 2010 indicated by Fd fell in grade III,accounting for 87.1%,and 0 fell in grade I;the fire locations were in good agreement with areas of high fire risk early warning.In fuel dry index ( Fd ) graph,it can be seen that Fd has close relationship with the prairie vegetation growing season;the early development of Fd is high,but later it exhibits decreasing trend;at the medium stage,Fd is low;at the late stage,Fd is high,and shows a trend of rising.Overall,the Fd index plays an important role in fire danger forecast at the grassland growing stage.