黄河下游城市群生态系统健康时空演变特征

Spatial and Temporal Evolutionary Characteristics of Ecosystem Health at Urban Agglomeration in Lower Yellow River Basin

[目的]研究城市土地扩张对黄河下游城市群生态系统健康的影响,并构建科学的生态系统健康评价模型以识别生态系统健康状态时空演变特征,为制定有效生态保护策略提供前提条件。[方法]以黄河下游城市群为研究区,构建VORS评价模型,以格网为研究单元对2000,2010和2020年黄河下游城市群生态系统健康水平进行动态评价。[结果]①2000—2020年,生态系统健康指数平均值从2000年的0.325下降到2020年的0.320,标准差从2000年的0.106上升到2020年的0.112。这表明研究区生态系统健康水平总体上呈现略微降低的趋势,生态系统健康等级高的地区更加健康,而等级低的地区生态系统不断恶化。②研究区生态系统健康水平空间异质性显著,各等级空间分布集中,从研究区中部延伸到东北部的大部分区域,生态系统健康程度表现为较差,占比高达约74%,整体生态系统健康水平脆弱。③2000,2010和2020年全局莫兰指数分别为0.512,0.522和0.543。这表明研究区生态系统健康分布在整体上具有正向的空间集聚效应,空间依赖性显著。[结论]黄河下游城市群生态系统健康水平整体上有所降低,生态系统健康状况不容乐观,生态环境保护与建设亟待加强,未来应着重于提高生态系统服务水平。

[Objective]Effects of urban land expansion on the ecosystem health of urban agglomeration in the lower Yellow River basin were studed.A scientific ecosystem health evaluation model was constructed to identify the spatial and temporal evolution characteristics of the ecosystem health status,in order to provide the prerequisite for formulating effective ecological protection strategies.[Methods]The VORS model was developed with urban agglomeration in the lower Yellow River basin as the study region,and the grid was used as the study unit to dynamically assess the ecosystem health of the urban agglomeration in 2000,2010 and 2020.[Results]①From 2000 to 2020,the mean ecosystem health index decreased from 0.325 in 2000 to 0.320 in 2020,and the standard deviation increased from 0.106 in 2000 to 0.112 in 2020,the health level of the ecosystem in the study area generally showed a slightly decreasing trend.Areas with high levels of ecosystem health were healthier,while those with low levels were deteriorating.②The spatial heterogeneity of the ecosystem health level in the study area was significant,and the spatial distribution of all levels was concentrated.In most areas extending from the middle of the study area to the northeast,the ecosystem health level was poor,accounting for up to about 74%,and the overall ecosystem health level was fragile.③The Moran’s I was 0.512,0.522 and 0.543 in 2000,2010 and 2020,respectively.The overall distribution of ecosystem health in the study area had a positive spatial agglomeration effect,with significant spatial dependence.[Conclusion]The overall level of ecosystem health in the urban agglomeration of lower Yellow River basin has decreased,the ecosystem health is not optimistic,ecological environmental protection and construction need to be strengthened,and in the future,people should focus on improving the level of ecosystem services.