西北地区三维生态足迹生态安全评价及驱动力分析

Ecological security evaluation and driving force analysis of three-dimensional ecological footprint in Northwestern China

西北地区生态脆弱,进行生态安全评估和驱动力分析具有重要意义。选取土地利用影像和植被净初级生产力产品叠加细化均衡因子和产量因子,利用三维生态足迹改进模型测算和空间刻画西北地区2009—2017年的足迹深度,足迹广度和区域三维生态足迹;然后基于上述结果计算生态压力指数、生态协调系数、生态足迹多样性指数、流量资本占用率和存量资本流量利用比描述生态安全变化;最后用STIRPAT扩展模型结合主成分回归模型分析三维生态足迹演变的主要驱动因素。结果表明:(1)2009—2017年研究区的区域足迹广度总体上呈现为先升后降的趋势,2009年最低为3.116 hm^(2)/人,2016年达到最高为3.796 hm^(2)/人;区域足迹深度研究期内一直上升,从2009年的11.550 hm^(2)/人上涨为19.031 hm^(2)/人;三维生态足迹研究期内也一直增加,由6.006 hm^(2)/人增加为9.760 hm^(2)/人。(2)研究区2009—2017年整体生态安全持续恶化,生态压力不断增大,其中宁夏生态安全形势严峻,新疆和陕西生态环境脆弱,甘肃生态安全程度相对较差,青海生态安全良好;不同地区地类的安全状况基本不同,但共同点为林地最为安全,化石能源用地最不安全。(3)驱动力分析模型表明,研究区经济、社会和技术发展对资本的占用有传导机制。人均GDP、城镇化率和人口是研究区增加生态资本占用的因素,万元GDP能耗是除新疆外共有的缓解资本亏损的因素,经济发展仍依靠消耗资本能源,需加大科技水平投入,提高能源利用效率;产业需要加速转型,完善经济体制,降低对资本的依赖性。

The eco-environment is fragile in the Northwestern China. It is of great significance to conduct ecological security evaluation and analysis of driving forces. This study selects land use images and net primary productivity products to refine equivalence factors and yield factors. The improved three-dimensional ecological footprint model is used to calculate footprint size, footprint depth, and three-dimensional ecological footprint of Northwestern China from 2009 to 2017. The footprint size and footprint depth from 2009 to 2017 are spatially visualized. We adopt the ecological pressure index, ecological footprint diversity index, ecological coordination index, occupancy rates of capital flows and use ratios of stock-flows to describe quantitatively changes in ecological security. Finally, the extended STIRPAT model combines with the principal component regression model to analyze the main driving factors that affect the evolution of the three-dimensional ecological footprint. The results showed that:(1) the ecological footprint size from 2009 to 2017 displayed the tendency declining at the beginning and rising up later. The lowest value was 3.116 hm^(2)/cap in 2009, and the highest one in 2016 was 3.796 hm^(2)/cap. The ecological footprint depth has been increasing from 11.550 hm^(2)/cap in 2009 to 19.031 hm^(2)/cap in 2017. The three-dimensional ecological footprint has also been increasing from 6.006 hm^(2)/cap to 9.760 hm^(2)/cap during the study period.(2) From 2009 to 2017, the ecological security of the study area continued to deteriorate. Among them, the ecological security situation in Ningxia was severe, the ecological environment in Xinjiang and Shaanxi was fragile, the ecological security was relatively poor in Gansu, and the ecological security in Qinghai was good. The security status of the productive land types in different regions were different, but the similarity was that forest land was the safest and fossil energy land was the least safety.(3) The driving force analysis model indicated that the economic, social and technological development of the study area had a transmission mechanism for the occupation of capital. Per capita GDP, urbanization rate and population were the factors that increased the occupation of ecological capital. The energy consumption of per 10,000 yuan of GDP was a factor that alleviated capital losses except Xinjiang. Economic development still relied on the consumption of capital and energy. It needed to increase the level of investment in science and technology, improve the energy structure, and increase the efficiency of energy utilization. The industry should accelerate the transformation, improve the economic system, and reduce the dependence on capital.