黄河流域黄土高原生态质量时空演变格局及其驱动因素

Spatiotemporal Evolution Pattern of Ecological Quality of the Loess Plateau and Its Driving Factors

[目的]量化分析自然与社会经济因素对黄河流域黄土高原生态质量格局演变的影响,为进一步提升黄河流域生态质量,促进区域生态可持续发展提供理论支撑。[方法]基于DPSIR模型框架,从社会经济状况、自然环境与生态治理方面选取14项指标,构建生态质量综合评价指标体系,采用层次分析法确定指标权重,采用加权平均法计算生态质量综合评价指数;构建岭回归模型,分析了其变化的驱动因子。[结果]黄河流域黄土高原生态质量具有明显时空异质性;生态质量较高区域集中分布在中游地区,较低区域集中分布在上游地区,整体呈“东南高、西北低”的空间格局;生态质量评估为中及以上水平区域面积占比由2000年的40.56%上升至2020年的70.36%;20年间生态质量提升的区域面积占研究区总面积的94.44%,提升的区县数量占总区县数的91.57%;岭回归模型可以解释生态质量99.4%的变异,植被覆盖度和年降水量对生态质量变化的相对贡献率较高。[结论]黄河流域黄土高原生态质量呈提升趋势,其时空分布格局主要受植被覆盖度和年降水量的驱动。建议在科学、合理增加植被覆盖度的基础上,进一步优化生态系统空间格局。

[Objective]This research aims to explore the temporal and spatial status of the ecological quality evolution and the main driving factors of its evolution in the Loess Plateau,and to provide the theoretical basis for the improvement of regional ecological quality and sustainable development in the Yellow River Basin.[Methods]Based on the‘Driving Force-Pressure-State-Impact-Response’(DPSIR)model,14 indexes reflecting the social and economic situations,natural environment and ecological governance were selected to build the comprehensive evaluation index system.The weight of each index was defined by the analytical hierarchy process(AHP),and the comprehensive evaluation indexes were calculated by the weighted average.The Ridge Regression Model was used to quantitively assess the driving factors of the ecological quality evolution.[Results]The ecological quality of the Loess Plateau in the Yellow River Basin exhibited a distinctive spatiotemporal heterogeneity,with the high-quality areas concentrating in the midstream and low-quality areas in the upstream,showing the unique spatial pattern of‘high-quality in the southeast and low-quality in the northwest’.The medium-quality areas and above increased from 40.56%in 2000 to 70.36%in 2020.The ecologically improved areas in the past 2 decades took up 94.44%of the total research area,and the ecologically improved counties accounted for 91.57%of the total counties.The Ridge Regression Model explained 99.4%of the ecological evolution,demonstrating the relatively higher contributions from the vegetative cover and the annual precipitation to such evolution.[Conclusion]The ecological quality in the Loess Plateau was improved,and the spatiotemporal evolution of ecological quality was mainly driven by vegetative cover and annual precipitation.It is recommended that the spatial pattern of ecosystems is further optimized on the basis of a scientific and rational increase in vegetation cover.