基于改进遥感生态指数的海南岛生态环境质量动态变化

Dynamic monitoring of ecological environment quality of Hainan Island based on improved remote sensing ecological index

为定量分析海南岛生态环境质量,基于耦合绿度、湿度、干度、热度4项指标的遥感生态指数(Remote sensing ecological index,RSEI),考虑土地利用强度、人口聚集度与坡度对海岛生态系统的影响,增加土地利用、人口分布、地形3项指标,利用主成分分析法构建了改进遥感生态指数(Improved remote sensing ecological index,IRSEI)模型。利用RSEI与IRSEI分别对海南岛2000—2020年的生态环境质量进行动态监测,分析IRSEI的合理性以及两者与生态环境状况指数(Ecological index,EI)的相似性。结果表明:与RSEI相比,IRSEI与EI指数更接近,且具有很好的合理性,IRSEI突出土地利用、人口分布与地形地貌对生态环境质量的影响,可以对海南岛生态环境质量进行准确、客观的评价。2000—2020年间海南岛生态环境质量呈现"下降-上升-下降"的变化趋势,但整体来说,IRSEI均值从0.721上升至0.766,其生态环境质量得到提升。生态环境质量等级为优、良的土地各年份占比均超过89%,等级为差、较差的土地占比极少,二者之和在各年份所占比例均低于1.48%;海南岛中南部地区的生态环境质量高于东部、北部以及环岛地区,生态环境质量总体处于优良水平。生态环境质量提升的区域覆盖面积为12278.00 km^(2),占比47.5%,生态环境质量有所下降的区域覆盖面积为3124.07 km^(2),占比12.1%;改善地区主要分布在北部和东部,退化地区主要分布在人口密集的环岛沿海城市带。研究构建了适用于海南岛的生态质量评估体系,为海南省生态环境的治理保护和相关政策法规的制定提供科学依据。

In order to quantitatively analyze the quality of Hainan Island′s ecological environment,besides the remote sensing ecological index(RSEI)that coupled with four indicators of greenness,humidity,dryness,and heat,we should consider the impact of land use intensity,population concentration and slope on the island′s ecosystem.Therefore,three other indicators of land use,population distribution,and topography were added,and the improved remote sensing ecological index(IRSEI)was constructed using principal component analysis.This study used RSEI and IRSEI to dynamically monitor the ecological environment quality of Hainan Island from;000 to 2020 and analyzed the rationality of IRSEI and the similarity between RSEI/IRSEI and the ecological index(EI).The results showed that compared with RSEI,IRSEI was closer to the EI index and had good rationality.It can highlight the impact of land use,population distribution and topography on the quality of the ecological environment.Therefore,it can accurately and objectively evaluate the quality of Hainan Island′s ecological environment.From 2000 to 2020,the quality of Hainan Island′s ecological environment showed a trend of"decrease-rise-decline".The average value of IRSEI rose from 0.721 to 0.766,which shows that the quality of the ecological environment of Hainan Island has been improved.The proportion of land with excellent and good ecological environment quality levels in each year was more than 89%,and the proportion of land with worse and worst ecological environmental quality levels was so small that the sum of the two accounts for the proportion of each year were below 1.48%.The quality of the ecological environment in the central and southern parts of Hainan Island was higher than that of the eastern,northern and around island areas.The quality of the ecological environment was good in generally.The area covered by the improved ecological environment quality was 12278.00 km^(2)that accounting for47.5%,and the area covered by the reduced ecological environment quality was 3124.07 km^(2)that accounting for 12.1%.The improved area was mainly distributed in the northern and eastern parts of Hainan Island,and the degraded region was mainly distributed in densely populated coastal cities around the island.The results can provide references for the future plan to improve eclogical environment in Hainan Island.