基于能值生态足迹模型的北方农牧交错带定西市生态安全评价

Ecological security evaluation based on emergy-ecological footprint model at the northern farming-pastoral ecotone in Dingxi city

为分析北方农牧交错带的生态安全问题,以北方农牧交错带典型代表区域定西市作为研究对象,运用能值生态足迹模型对该区域的生态安全状况进行了长时间序列研究。研究发现:1995—2019年间定西市人均能值生态承载力从0.61 hm^(2)·人^(-1)增加到0.75 hm^(2)·人^(-1),人均能值生态足迹从1.22 hm^(2)·人^(-1)增加到1.60 hm^(2)·人^(-1)。从人均能值生态足迹的构成组分来看,耕地人均能值生态足迹对定西市人均能值生态足迹的贡献最大,其次是草地人均能值生态足迹。25年间,定西市始终处于生态赤字状态,万元GDP生态足迹从11.92 hm^(2)·万元^(-1)下降到1.09 hm^(2)·万元^(-1),生态足迹多样性指数由0.92变化到1.44,生态协调系数从1.34变化到1.33,生态压力指数由2.01上升到2.15,发展能力指数由1.12变化到2.32,生态安全等级在危险和不安全之间变化,生态安全问题亟待解决。

In order to analyze the ecological security of the northern farming-pastoral ecotone,this study took Dingxi City,a typical representative region of the northern farming-pastoral ecotone,as a research object,and used the emergy-ecological footprint model to examine the ecological security situation in this area for a long time series.The results revealed that from 1995 to 2019,the emergy ecological carrying capacity of per capita in Dingxi increased from 0.61 hm^(2)·cap^(-1) to 0.75 hm^(2)·cap^(-1),and the emergy ecological footprint of per capita increased from 1.22 hm^(2)·cap^(-1) to 1.60 hm^(2)·cap^(-1).From the components of emergy ecological footprint,the emergy ecological footprint of cultivated land contributed the most to Dingxi,followed by the grassland.Over the past 25 years,Dingxi City has been in ecological deficit,which is expanding.The ecological footprint of ten-thousand-Yuan GDP has decreased from 11.92×10^(4) hm^(2)·CNY^(-1) to 1.09×10^(4) hm^(2)·CNY^(-1).The diversity of ecological footprint has changed from 0.92 to 1.44.The ecological coordination coefficient has decreased from 1.34 to 1.33.The ecological pressure index has increased from 2.01 to 2.15,development capacity index has increased from 1.12 to 2.32.The level of ecological security has changed between at risk and unsafe,and the problem of ecological security needs to be solved urgently.