Abstract:

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 multifactor 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.

Key words: remote sensing, forest, fuel, load