基于耦合协调度模型的黄土高原生态环境质量测度及预测

Measurement and prediction of eco-environmental quality on the Loess Plateau based on coupled coordination degree model.

生态环境质量评价作为生态文明建设的基本依据,对于积极适应气候变化、合理开发及保护生态环境等具有重大意义。本文以生态环境脆弱的黄土高原为研究区,基于植被覆盖度、地形位指数、人口密度等数据反演资源环境承载力,以MODIS数据和土地利用数据表征生态弹性限度,分析2000—2020年研究区资源环境承载力与生态弹性限度的演变特征,利用耦合协调度模型综合表征区域生态环境,通过标准差椭圆方法探究协调度的重心变化及转移路径,并在此基础上利用粒子群优化的Elman神经网络对生态环境的未来趋势进行预测。结果表明:2000年以来黄土高原资源环境承载力呈现东南高、西北低的分布格局,呈指数缓慢上升趋势(0.0625 a-1),生态弹性限度与该区域土地利用格局呈高度一致,指数波动上升但整体水平低;黄土高原生态环境耦合协调度从轻微失调阶段转变为初级协调阶段;黄土高原生态环境协调发展度的重心向东南偏移,且呈现东北-西南方向向心聚集,西北-东南方向空间发散的趋势;预测发现,2030年各市(自治州)资源环境承载力-生态弹性限度系统耦合协调度将稳步上升,这表明未来黄土高原的生态环境质量将逐步趋于协调,但各地的增长速度将存在显著差距。

As a basis of ecological civilization construction,the assessment of eco-environmental quality is of great significance for adapting to climate change and reasonably developing and protecting eco-environment.Based on vegetation coverage,terrain index and population distribution,and ecological elasticity limit derived from MODIS and land use dataset from^(2)000 to 2020,we assessed the evolution of environmental carrying capacity of the Loess Plateau with highly fragile eco-environment.The coupling coordination degree model was used to comprehensively characterize the regional eco-environment.A standard deviation ellipse method was used to investigate the change of center of gravity and the transfer path of coordination degree.Elman Neural Network with particle swarm optimization was used to predict the future trend of ecological environment.The results showed that since 2000,the environmental carrying capacity of the Loess Plateau exhibited a spatial pattern with higher in the southeast and lower in the northwest,and the index increased slowly with a rate of 0.0625 per year.The ecological elasticity limit was consistent with land use pattern,and the index exponentially ascended with a low level.The coupled coordinate coefficient changed from slight discordance to primary coordination.The core of coupled coordination degree shifted to southeast and exhibited a spatial pattern with centripetal aggregation in the northeast-southwest direction and diffusion in northwest-southeast direction.It is predicted that the system coupling coordination degree of environmental carrying capacity and ecological elasticity limit will increase steadily in 2030,which indicates that the eco-environmental quality of the Loess Plateau will gradually become coordinated in the future,but with significant difference in the growth rate of different regions.