漓江流域沿岸风光带植被覆盖度的遥感动态监测与估算

Remote Sensing Dynamic Monitoring and Evaluation on Lijiang River Scenic Belt Vegetation Coverage

以1990、2008年TM影像和2001年ETM+影像为数据源,研究漓江精华段沿岸风光带植被覆盖度的动态变化规律,采用归一化植被指数(NDVI)像元二分模型,半定量估算了研究区的植被覆盖度,生成了不同时相的植被覆盖度等级图及面积转移矩阵,并结合植被覆盖度的监测结果对研究区植被覆盖度的变化趋势进行建模分析。结果表明,研究区1990、2001和2008年均以高植被覆盖度等级为主,估算的面积分别为207.058、216.538和232.795 km2。1990—2008年间,研究区内植被覆盖度稳定不变的区域占总面积的44.887%,减少和增加的区域分别占总面积的22.077%和33.036%,说明植被覆盖度总体上呈现增加的趋势;结合1990—2001年和2001—2008年的变化分析结果,植被覆盖度变化趋势是先略微增加,后显著增加,与植被覆盖度均值走势一致,从定量遥感的角度证明了漓江精华段沿岸风光带的绿色生态环境得到了快速的改善。

TM images （in 1990, 2008） and ETM images（ in 2001 ） are studied for the change regulation of the Lijiang River scenic belt vegetation coverage. Normalized Difference Vegetation Index （NDVI） in pixel two models is used to estimate the vegetation coverage information of the study area and generate different periods of vegetation coverage grade map and area transfer matrix. Vegetation coverage change monitoring results help the analysis of the change trend of the vegetation coverage. The results show that vegetation coverage estimations were respectively 207. 058, 216. 538 and 232. 795 km2 in 1990, 2001 and 2008. From 1990 to 2008, the study area vegetation coverage accounted for 44. 887%. The reduced and the increased areas are respectively 22. 077% and 33.036% of the total area. From 1990 to 2008, the vegetation coverage of the study area ten- ded to increase. Change analysis from 1990 to 2001 and from 2001 to 2008 shows a slightly increased tend of vegetation coverage, steadily increasing, consistent with the vegetation coverage trend. Remote sensing proves that the green ecological environment of the Lijiang River scenic belt has been improved.