煤炭资源型城市生态安全评价——以锡林浩特市为例

煤炭资源型城市生态安全评价能够协调人口、资源和环境之间的矛盾,保障城市可持续发展。基于PSR模型,以煤炭资源型城市锡林浩特市为研究区域,从生态环境和社会经济方面共选取了33个指标因子,构建了煤炭资源型城市的生态安全评价指标体系,运用熵权TOPSIS法进行了城市生态安全综合评价,并通过障碍度模型对城市生态安全的主要障碍因子进行了研究。研究结果表明:(1)2008—2017年锡林浩特市生态安全水平总体呈缓慢上升趋势。生态安全综合评价指数从0.464上升到0.553,安全等级由较不安全转为临界安全状态;(2)10年间PSR三大指数表现出不同变化特征。压力指数呈下降后上升再小幅下降的变化趋势,状态指数呈波动上升趋势,响应指数呈快速上升趋势;(3)子系统的障碍度分析表明压力系统的障碍度最大,是影响煤炭资源型城市生态安全的首要因素。子系统的障碍度变化趋势表现为:压力系统和状态系统的障碍度均不同程度增大,响应系统的障碍度越来越小;(4)单项指标的障碍度分析表明影响该资源型城市生态安全的主要障碍因子集中在压力系统和状态系统,10年间最大障碍因子经历了从城镇化率到矿区面积的演变。

Ecological security evaluation on the coal resource-based city:a case of Xilinhot City

The ecological security evaluation of a coal resource-based city can help manage the imbalance between a population, resources, and the environment, so as to ensure sustainable development of the city. The entropy weight TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) model was used to evaluate the ecological security of Xilinhot, a coal resource-based city; an obstacle factor of the city was then diagnosed through an obstacle degree model. The entropy weight TOPSIS method helps fully utilize original data, enabling a comprehensive assessment of the ecological security of an urban ecosystem, revealing each indicator level as well as the key factors affecting a system. An eco-security evaluation index system involving 33 indexes was established under a PSR (Press-State-Response) model based on aspects of ecological environment and social economy. The results showed that: (1) The development of ecological security levels in Xilinhot city, as a whole, increased gradually from 2008 to 2017. The safety level changed from less safe to critical as the index increased from 0.464 to 0.553; (2) The three PSR indices showed different characteristics in the last 10 years. The pressure index trend demonstrated an increase, following a decrease; decreasing slightly thereafter. The state index increased in a fluctuating manner, and the response index demonstrated rapid growth; (3) The subsystem obstacle degree indicated that the pressure system was the primary factor affecting the ecological security of the coal resource-based city. The obstacle degree of the pressure and state system increased by an annual average of 6.04% and 2.11%, respectively, but that of the response system decreased by 11.15%; (4) Considering the index layer, the main factors affecting ecological security are attributed to the pressure and state systems. In 2008-2012, the obstacle degree of urbanization rate was maximum; in 2013-2017, the first obstacle factors changed, and mineral area became the major obstacle factor.