基于MFA和STIRPAT的定西市物质输入输出及环境压力

Regional sustainable development of Dingxi eco-economic system based on material flows analysis

运用物质流分析方法,对定西市生态经济系统分析结果表明:在不考虑水的情况下物质输入和输出分别以2.24%和5.68%的速度波动缓慢上升;物质输入上升速度低于物质生产力上升速度和物质利用强度降低速度,单位GDP污染物排放强度以年均6.59%的速度直线下降,可见物质利用效率的提高速度较快,而2004-2008年,物质生产力每年提高2.52%,物质利用强度年均降低2.27%,均小于物质输入增加速度,反映资源压力有增加倾向;人均污染排放强度年均以2.43%的速度缓慢上升,并通过构建STIRPAT模型发现,人均GDP和第一、二产业对环境压力呈正显著性影响,环境压力有增大趋势;目前,资源利用效率提高速度较快,单位GDP污染物排放强度逐渐降低,表现出经济与环境逐步协调发展.然而,依照现行模式继续发展,资源和环境压力持续增加,定西生态经济系统处于不可持续发展的状态.

The material inputs and outputs of Dingxi eco-economic system were analyzed using material flow analysis. It was found that, excluding water, the material input and output amount increased fluctuantly at the mean annual rates of 2.24% and 5.68% slowly. Both material productivity and utilization intensity were lower than the rate of material input increase, and the intensity of pollutant output per GDP decreased at the mean rate of 6.59%, approximately to a straight line. The results show that the rate of resource utilization efficiency rose faster, but material productivity increased at the mean annual rate of 2.52% and material utilization intensity decreased at the mean annual rate of 2.27% from 2004 to 2008, and the rate of material productivity and utilization were lower than the rate of material input. The results suggested that resource stress has been accelerating. The intensity of pollutant output per person decreased slowly at the mean rate of 2.43%. The STIRPAT model was used to quantify the impact of various driving forces on pollution outputs. The results show that GDP per person, the first and second industrial structure had a significantly positive effect on the pollutants output, suggesting that environmental stress had the trend to increase. The material utilization efficiency was increasing and the intensity of pollutant output per GDP was being reduced, suggesting that the economic growth have been accompanied by gradual environmental impact. The stress of resource and environment are increasing with the economic growth and the eco-economic system is not developing towards an sustainable direction.