龄组植被指数的构建及其初步应用研究

林龄(龄组)是划分林分结构的主要指标之一，其对监测森林健康，推进森林可持续发展具有重要意义。本文提出一种基于遥感数据的龄组植被指数(AGVI)，并对其可行性进行验证。以福建省三明市、将乐县、沙县、南平市、华安县、云霄县、南安市、安溪县、莆田市、长汀县、建阳市、宁德市及福清市等13个县(市)518组松林龄组数据及同时相HJ-1 CCD多光谱影像为基础，对各龄组松林冠层的蓝光、绿光、红光、近红外及NDVI的光谱差异性进行分析，各龄组在近红外波段表现为幼龄林＞中龄林＞过熟林＞成熟林＞近熟林的特征，NDVI则表现为成熟林＞近熟林＞过熟林＞幼龄林＞中龄林的特征，由此构建龄组植被指数AGVI;该指数可以扩大各龄组松林的绝对及相对光谱差异。采用K-均值法对松林AGVI进行聚类分析，结果显示，松林龄组的划分精度为80.45%，准确率为90.41%。由此证实本文所构建的龄组植被指数具备有效性。

Construction of Age Group Vegetation Index and Preliminary Application

In the present paper, one remote sensing index-age group vegetation index (AGVI) was put forward, and its feasibility was verified. Taking 518 groups of pine forest age group data collected in 13 counties (cities) of Sanming, Jiangle, Shaxian, Nanping, Huaan, Yunxiao, Nanping, Anxi, Putian, Changting, Jianyang, Ningde and Fuqing, Fujian Province and HJ-1 CCD multi-spectral image at the same time-phase as the basis, the spectrum differences of blue, green, red, near infrared and NDVI of each age group were analyzed, showing the characteristics of young forest>middle-aged forest>over-mature forest>mature forest>near mature forest at near infrared band and mature forest>near mature forest>over-mature forest>young forest>middle-aged forest at NDVI, thus the age group vegetation index(AGVI) was constructed; the index could increase the absolute and relative spectrum differences among age groups. For the pine forest AGVI, cluster analysis was conducted with K-mean method, showing that the division accuracy of pine forest age group was 80.45%, and the accurate rate was 90.41%. Therefore, the effectiveness of age group vegetation index constructed was confirmed.