基于遥感生态指数的永定客家土楼遗产地生态评价

Ecological Evaluation About Yongding Hakka Tulou Heritage Based on Remote Sensing Ecological Index(RSEI)

基于永定区1988、1996、2002、2009、2014年5期Landsat系列卫星影像,利用新型遥感生态指数(RSEI)评估了研究区生态变化状况,并分析了土地覆盖变化与生态变化之间的关系。结果表明,除1988-1996生态质量改善不佳外,永定区总体生态质量呈现逐年提升,其RSEI均值从1988年0.615下降到1996年0.594后,分别提升到2002年0.616、2009年0.634和2014年0.685,生态优良等级所占面积比例也由1988年65.9%下降到1996年61.50%后,分别提升到2002年65.46%、2009年68.84%、2014年77.03%。从空间分布上来看,永定区生态质量变好区域位于坡耕地、原有中高海拔的退化地/开垦地、灌木/草地转化为林地区域;变差区域集中在林地退化为灌木、草地及开垦地区域,以及城镇周边扩展区域。总的来说,永定区生态环境状况呈逐渐改善趋势。

Five Landsat remote sensing images are used in this study,which represent the years of1988,1996,2002,2009,and2014,respectively.Ecological changes were evaluated by a newly remote sensing ecological index(RSEI),and the relationship between land cover change and ecological change wasanalyzed.The results show that the overall ecological quality has,year by year except1988-1996,improved in Yongding District.The mean values of RSEI fell from0.615in1988to0.594in1996,and then increased to0.616in2002,0.634in2009and0.685in2014.The proportion of high-grade RSEI area also fell from65.90%in1988to61.50%in1996,and then increased to65.46%in2002,68.84%in2009,77.03%in2014.The spatial analysis of the ecological change of Yongding revealed that the ecological quality has improved in the slope farmland,degraded land at high altitude,shrub and grassland which were converted into forest land,and become worse in the urban expansion area and the forest land which degraded to the area of shrub,grassland and degraded land and clearage forest.Generally speaking,the ecological environment of Yongding district become better and better.