2000—2020年福州市植被覆盖度时空变化分析

Spatio-temporal variations in vegetation coveragein Fuzhou City from 2000 to 2020

该研究选取福州市2000,2005,2010,2015,2020年5期的Landsat遥感影像数据,运用ENVI5.3与ArcGIS10.2,在对影像预处理后得出其归一化差分植被指数(NDVI),并与像元二分模型相结合得出植被覆盖度,结合差值法、均值法、空间自相关等方法对福州各地区植被状况进行分析,研究2000至2020年福州市植被覆盖度的时空分布及变化特点。结果表明:福州市的总体植被覆盖水平较高,其植被覆盖度分布呈现西部和北部普遍高于东南部地区,沿闽江流域地区与沿海地区的植被覆盖度普遍较低;永泰县、闽清县、闽侯县等地势较高且人为活动因素较少的地区,植被覆盖水平较高。福州主城区与东南沿海地区的植被覆盖度由2010年前的明显退化,在2010年后间转变为明显改善,但诸如永泰县的某些高植被覆盖度区域,由2010年前明显改善在后10 a间转变为明显退化。福州市政府森林城市建设,特别是对主城区与沿海地区植被的改善已卓有成效,但也要注意开发西部地区乡村旅游观光、森林产业对原有绿色生态的影响。

In this study,the triple-period Landsat images of Fuzhou City from 2000 to 2020 was selected.Through ENVI 5.3 and ArcGIS 10.2,the normalized difference vegetation index(NDVI)was calculated and combined with the pixel dichotomy model to get the vegetation coverage.With mean method and other methods,the vegetation status of each region was analyzed.The result shows that the vegetation cover level was detected to be high in Fuzhou.Fractional vegetation cover was generally higher in the west and north than that in the southeast.Judged from the data,the vegetation coverage along the Minjiang River Basin and the southeast coastal accounted for lower proportion,on the contrary,the higher vegetation coverage mainly concentrated in Yongtai County,Minqing County,Minhou County and other areas characteristic of higher terrain and less human activity.Main urban area of Fuzhou and the southeast coastal were,in vegetation coverage,changed from‘obvious degradation’before 2010 to‘significant improvement’later.However,high vegetation coverage areas like Yongtai County changed from‘significant improvement’before 2010 to‘obvious degradation’later.Significant improvements have been made in the construction of forest city by Fuzhou Municipal Government,especially in the vegetation enhancement in the main urban area and coastal areas.But more attention should be paid to the impact of tourism on the original green ecology in developing rural tourism and forest industry in the western region.