黄河上游兰州-西宁城市群资源环境承载力时空分异及障碍因子诊断

基于PSR模型构建资源环境承载力评价体系,利用熵权法、综合指数模型和GIS的空间分析功能对兰州-西宁(兰西)城市群资源环境承载力进行时空动态剖析,并运用障碍度模型识别其障碍因子。结果表明: 2005—2018年,兰西城市群资源环境承载力呈波动上升态势,资源环境承载力状况较好;资源环境承载力变异系数亦有波动上升趋势,区域差异逐步扩大。资源环境承载力空间上总体呈现以兰州与西宁主城区为中心的“双核”结构特征,高水平区主要集中于以兰州市和西宁市为中心的河湟谷地及其周边部分县区,低水平区集中于城市群中部、南部地区。其中,资源环境承载力子系统指数的时空分异特征显著,压力指数呈波动下降态势,空间上呈现以兰州与西宁市区为中心向外围地区递减的分布特征;状态指数呈波动上升态势,呈东西两翼高、中部低的空间演化特征;响应指数整体呈上升态势,空间上呈东高西低、中高外低的格局特征。城镇化率、人均工业废水排放量、生活垃圾无害化处理率、水耗指数和环保投资占GDP比重是制约兰西城市群资源环境承载能力提升的主要障碍因子。

Spatiotemporal variation and obstacle factor diagnosis of resource and environment carrying capacity of Lanzhou-Xining urban agglomeration in the upper Yellow River,Nothwest China

Based on the PSR model, we built an evaluation system for resource and environment carrying capacity. We used the entropy weight method, the comprehensive index model and the spatial analysis function of GIS to explore the spatial-temporal dynamic of the resource and environment carrying capacity of the Lanzhou-Xining urban agglomeration, and used the obstacle degree model to identify the obstacle factors. The results showed that resource and environment carrying capacity of the Lanzhou-Xining urban agglomeration from 2005 to 2018 showed a fluctuating upward trend, which was generally at good condition. The coefficient of variation of resource and environment carrying capacity had a fluctuating upward trend, while regional differences were gradually expanding. Spatially, resource and environment carrying capacity presented a “dual-core” structure centered on the main urban areas of Lanzhou and Xining. The high-level areas were mainly concentrated in the Hehuang Valley with Lanzhou and Xining as the center and some surrounding counties, while the low-level areas were distributed in the central and southern regions of the urban agglomeration. Among them, there were spatiotemporal variations of the subsystem index. The pressure index showed a fluctuating and decreasing trend, and spatially showed a decreasing distribution characteristic from Lanzhou and Xining urban areas to the peripheral areas. The state index showed a fluctuating upward trend, and spatially showed the evolution characteristics of high in the east and west wings and low in the middle. The response index showed an upward trend, and spatially showed distribution patterns high in the east and middle, and low in the west and outside. The urbanization rate, per capita industrial wastewater discharge, domestic waste harmless treatment rate, water consumption index, and the proportion of environmental protection investment in GDP are the main obstacles restricting the improvement of resource and environment carrying capacity of Lanhzhou-Xining urban agglomeration.