基于多源数据的小清河流域生态环境时空变化分析

Analysis of temporal and spatial variations of ecological environment in Xiaoqing River Basin based on multi-source data

为揭示区域发展与生态环境质量之间的关系,在黄河流域生态保护和高质量发展的背景下,以小清河流域作为研究区,选取2009年、2015年和2021年的Landsat影像为数据源,耦合绿度、湿度、干度和热度4个指标,运用主成分分析得到遥感生态指数(remote sensing-based ecological index,RSEI),对研究区生态环境进行时空变迁分析。同时,在RSEI的基础上引入社会属性的兴趣点(point of interest,POI)数据构建改进遥感生态指数(modified RSEI,MRSEI),与RSEI进行对比分析。结果表明:该区域RSEI总体上呈现先下降后上升的趋势,2009年、2015年和2021年的RSEI均值分别为0.51、0.41和0.60,变好区域面积为3842.69 km2,占比达44.70%,变好区域主要为中部和北部地区;半生态用地变化最明显,有16.70%的半生态用地转变为生态用地,14.38%的半生态用地转变为非生态用地;相比于RSEI,MRSEI更接近生态环境指数(ecological index)值,能够更准确分析该区域生态环境变化与人类活动的关系,具有较好的区域适用性。

Under the context of ecological protection and high-quality development of the Yellow River basin,we assessed the relationship between regional development and ecological environment quality in the Xiaoqing River basin,with Landsat images from 2009,2015,and 2021 as the main data source.Coupled with four indicators(greenness,wetness,dryness,and heat),the remote sensing-based ecological index(RSEI)was obtained using principal component analysis,and the spatial and temporal variations of ecological environment in the study area were analyzed.On the basis of RSEI,the point of interest(POI)data of social attributes were introduced to construct the modified RSEI(MRSEI),which was compared with the RSEI for analysis.The results showed that the RSEI of the region showed a general trend of decreasing and then increasing,with mean values of 0.51,0.41,and 0.60 in 2009,2015,and 2021,respectively.The area of improved land was 3842.69 km2,accounting for 44.70%of the total area.The improvement area was mainly in the central and northern parts.The change of semi-ecological land was the most obvious,with 16.70%of land converted to ecological land and 14.38%of land converted to nonecological land.Compared with RSEI,MRSEI was closer to the ecological index value,and could more accurately describe the relationship between ecological environment changes and human activities in this region,with better regional applicability.