对采用遥感图像估测森林可燃物载量的方法进行综述。首先将现有方法根据对像元载量的分配方法,分成直接分配法和间接分配法2种。直接分配法分成聚类分析法和判别分析法;间接分配法分为简单植被特征法、林分模型法和综合因子约束法3种。然后对各方法的优缺点进行评价,指出现有方法整体准确率不高的不足,并分析产生误差的3个来源:1)从遥感图像判读中间特征所产生的误差;2)从中间特征到可燃物载量之间的误差;3)使用可燃物模型所产生的误差。据此提出改进现有方法、提高估测准确率的3个思路:1)使用新图像,如更高分辨率遥感图像、雷达图像或混合图像;2)选择更合适的中间特征以及它们与可燃物载量的关系模型;3)使用连续变量来描述可燃物载量。
Loads and their spatial distribution of forest fuels are basic information for forest fire management. The major method currently used for obtaining the information is by means of remote sensing imagery. The state of art of estimating forest fuel loads by remote sensing imagery was reviewed here. The methods were grouped into two classes at first: direct ones and indirect ones. The direct ones were classified into two categories: the clustering method, and the discriminant method and the indirect ones into three categories: the simple vegetation feature method, the stand modeling method and the muhifactor constraint method. Advantages and disadvantages of the methods were evaluated. And it was pointed out that accuracies of the methods were still relatively low as a whole. Three sources of errors were explored: 1)From interpretation of middle variables from remote sensing images; 2)From the step of estimating load from middle variables; 3)From the use of fuel models. Based on the above analysis, three ways possible improving accuracies of current methods were proposed: 1 )Using new imageries such as higher spatial resolution images, radar images or mixed images; 2)Choosing other more suitable middle variables and stand models; 3)Using successive variables for fuel description.