黄河流域生态环境脆弱性评价、空间分析及预测

Evaluation,spatial analysis and prediction of ecological environment vulnerability of Yellow River Basin

生态环境脆弱性是制约经济可持续、高质量发展的重要因素。以2005—2018年黄河流域73个城市为研究对象,构建了黄河流域生态环境脆弱性的评价指标体系,采用主成分分析计算了黄河流域生态环境脆弱指数,并依据自然断点法将评价结果分为极度脆弱、重度脆弱、中度脆弱、轻度脆弱、微度脆弱五类。进一步通过空间相关分析揭示了黄河流域生态环境脆弱性的时空演变特征,并利用CA-Markov模型对黄河流域2025年生态环境脆弱性进行了预测。结果表明:(1)黄河上、中、下游生态环境脆弱性分别表现“低—中—高”的分布特征,且生态环境脆弱性变化趋势存在区别:上游虽差异较大但波动相似,中游波动方向相反,下游在2016年之后整体呈下降趋势。(2)黄河流域生态环境脆弱性存在空间相关性,上游呈现低—低聚集,下游呈现高—高聚集,中游空间相关性不显著。(3)预测2025年黄河流域中游地区重度脆弱有所扩张,下游地区极度脆弱向中心区域明显收缩。黄河流域生态环境的治理与保护并非一朝一夕之事,也并非某一流域单独能够完成的,黄河上、中、下游要根据不同的自然条件制定与之相适宜、符合整体发展需要的治理与保护措施。

The vulnerability of ecological environment is an important factor restricting the sustainable and high-quality development of economy.Taking 73 cities in the Yellow River Basin as the research objects,we constructed an evaluation index system of the ecological environment vulnerability of the basin from 2005 to 2018.Principal component analysis was used to calculate the ecological environment vulnerability index.According to the natural break point method,the cities were divided into five categories:extreme vulnerability,severe vulnerability,moderate vulnerability,light vulnerability and slight vulnerability.In addition,through spatial correlation analysis,the spatiotemporal evolution characteristics of the ecological environment vulnerability of the study area are revealed.The ecological environmental vulnerability in 2025 is predicted by CA-Markov model.The results showed that:(1)The vulnerability of ecological environment in the upper,middle and lower reaches of the Yellow River shows the distribution characteristics of"low,medium and high",respectively.And there are differences in the variation trend of the ecological environment vulnerability:although there are large differences in the upper reaches,the fluctuations are similar,the fluctuation direction is opposite in the middle reaches,and a downward trend occurred after 2016 in the lower reaches.(2)The vulnerability of ecological environment is spatially correlated.The upper reaches show low-low aggregation,the lower reaches show high-high aggregation,and the spatial correlation in the middle reaches is not significant.(3)It is predicted that the severe vulnerability in the middle reaches will expand in 2025,while the extreme vulnerability in the lower reaches will contract to the central region.The management and protection of the ecological environment in the Yellow River Basin is not a matter of one day,nor can it be completed by one basin alone.The upper,middle and lower reaches should formulate appropriate management and protection measures according to different natural conditions to meet the needs of the overall development.