Evaluation of ecological security in Tongling City,Anhui,China
安徽铜陵市生态安全评价研究

Tongling city is an important production base of non-ferrous metals.Dramatic ecological pressures from long-term mining,smelting and processing have made eco-security a very serious problem.This study develops the evaluation index system and the urban eco-security pressure and response index model.Set Pair Analysis (SPA)-variable fuzzy set (VFS) comprehensive analysis method are adopted for timing evaluation on eco-security in Tongling city.Evaluation result shows that:1Since 2000,the ecosystem of Tongling city has been in less safety or critical safety level,the security level are generally low.As a turning point,eco-security improved from critical safety to less safety in 2003.2The change trend of pressure and response index reflected the eco-security mechanism between subsystems.Since 2000,ecological control measures in Tongling city reduced the system pressure,while because of the insufficient environmental resources,eco-security kept at the lower level.3Main factor affecting the security of the system is comprehensive factor of eco-environmental stress,comprehensive factor of resource constraints,and comprehensive factor of environmental input response.