杨树林全生长期LAI遥感估算模型适用性

The applicability of leaf area index estimation model in an aspen forest over a growth period

基于时间序列的植被叶面积指数(LAI)估算方法一直是遥感领域研究的热点,对植被全生长期LAI进行估算以跟踪其生长情况具有重要的实用意义。以此为出发点,以滁州地区杨树林为研究对象,获取多时相环境卫星CCD(简称HJ-CDD)遥感影像,并利用LAI-2000同步测量杨树林叶面积指数(LAI)。使用归一化植被指数(NDVI)分别建立展叶期、花果期、叶面积稳定期和落叶始期的LAI估算模型,通过对比分析得到了全生长期LAI估算模型,并利用实测LAI对估算LAI进行了验证。最后进一步对该模型的适用性进行了验证,结果表明,此模型对于各个时期LAI的估算具有一定的适用性和有效性,可用于全生育期的遥感LAI生成,从而为LAI的动态变化监测提供了一种有效的研究思路和方法途径。

Estimation of leaf area index （LAI） time series is a hotspot in remote sensing, because it allows tracking of vegetation biomass changes over a growth period. In this study, we acquired multi-temporal HJ-CDD remote sensing images of an aspen forest in Chuzhou area and synchronously measured LAI using LAI-2000. LAI estimation models of different growth stages （ leaf production, flowering, fruit bearing, leaf constant period, and leaf abscission period） were constructed using normalized difference vegetation index （NDVI）. Contrastive analysis was used to obtain LAI estimation model of the aspen forest over a growth period and estimated LAI was verified. The results showed that the model could be applied to estimate LAI over a growth period and provide useful information on the dynamic monitoring change of LAI.