2005-2018年黄河三角洲景观格局脆弱性的时空变化规律

Temporal and Spatial Variations of Landscape Pattern Vulnerability in Yellow River Delta During 2005-2018

[目的]研究黄河三角洲景观最适宜分析粒度、尺度,并进行景观格局脆弱性演变规律分析,为土地资源的可持续利用和生态环境建设提供理论依据。[方法]以2005,2012,2018年3个时期的Landsat遥感影像为数据源,运用景观格局指数法、变异系数法从景观水平和类型水平两个角度确定研究区最佳空间分析粒度;运用网格法和地统计方法,确定最佳空间分析尺度;在此基础上计算3个年份黄河三角洲景观格局脆弱度指数,并分析其时空演变及空间关联特征。[结果]①2005—2012年和2012—2018年两个研究时段内,黄河三角洲建设用地(10.1%,10.0%)、未利用地(-7.7%,-9.4%)动态度较大;②黄河三角洲最适宜景观分析粒度为220 m;最适宜景观分析尺度为3 km×3 km;③景观格局脆弱性从沿海到内陆逐渐增加,高脆弱区主要分布在北部和东部沿海处,低脆弱区广泛分布于中部和西南部;④Moran’s I系数逐年升高,2005,2012,2018年分别为0.354,0.365,0.399,空间聚集效应日益明显。[结论]研究时段内黄河三角洲景观格局脆弱性有逐渐恶化趋势,且空间上的差异较为显著。

[Objective]The most suitable granularity and scale for landscape analysis of the Yellow River Delta were determined,and spatiotemporal changes in landscape pattern vulnerability was analyzed in order to provide a theoretical basis for the sustainable use of land resources and environmental construction.[Methods]The landscape pattern index method and the coefficient of variation method were applied to Landsat remote sensing images from 2005,2012,and 2018 to determine the most suitable spatial analysis granularity of the study area from the perspective of landscape level and type level.The grid method and geostatistical method were used to determine the most suitable spatial analysis scale.On this basis,the vulnerability indexes of the landscape pattern of the Yellow River Delta in the three study years were separately calculated,and the characteristics of their temporal and spatial evolution and spatial correlation characteristics were analyzed.[Results]①During the two study periods(2005—2012,2012—2018)construction land area in the Yellow River Delta increased by 10.1%and 10.0%,respectively,and unused land area changed by-7.7%and-9.4%;②The most suitable granularity for the landscape analysis in the Yellow River Delta was 220 m,and the most suitable analysis scale was 3 km×3 km;③The vulnerability of landscape pattern gradually increased from the coastal area to the inland area.High-vulnerability areas were mainly located in the northern and eastern coastal areas,and the low-vulnerability areas were widely distributed across the central and southwestern regions;④Moran’s I coefficient increased over time,being 0.354,0.365,and 0.399,in 2005,2012,and 2018,respectively,indicating an increasingly obvious spatial aggregation of landscape pattern vulnerability.[Conclusion]During the study period,the vulnerability of the landscape pattern in the Yellow River Delta gradually deteriorated,and the spatial differences became more significant.