基于植被指数的秦岭森林健康评价方法研究

利用HJ-1/HIS L2级高光谱数据提取敏感反应森林健康状况的植被指数,用敏感性分析法筛选指标,建立评价森林健康的指标体系与评价模型。基于层次分析法获得评价模型中各指标的权重。采用自然间断点分级法将森林健康指数分为4个等级,分别为不健康、亚健康、健康和优质健康,绘制健康状况分布图。从小班和样地二水平验证该森林健康评价模型的精度,结果表明,评价结果在二水平上均与传统调查方法获得的结果显著相关。决定系数分别为0.707和0.665。该模型所得森林健康指数小于传统调查结果,但趋势一致。

Forest Health Assessment Method in Qinling Mountains Based on theVegetation Indices

Based on the HJ-1A L2 hyperspectral data, this paper extracted vegetation indexes which were sensitive to the forest health and screened the reasonable evaluation indexes by means of sensitivity analysis. The model to evaluate the health status of the sample area was established. We worked out the weights of the indexes by analytic hierarchy process and reclassified the FHI into four levels(unhealthy, sub-healthy, healthy, good-healthy)based on the natural discontinuity classification method. The distribution map of the forest health level was drawn; the precision of the model on the stand level and the sample plot level was verified. The results demonstrated that there was significant correlation between the result we obtained from the model and the traditional investigation method both on the two levels. The determination coefficients reached 0.707 and 0.655, respectively. The FHI of the model was below which of the traditional investigation method. Nevertheless, the trend was the same.