基于VSD模型的区域生态系统脆弱性评价--以广西西江经济带为例

摘要

The interactive effects of natural and human factors on ecosystems have been well studied, and the quantitative assessment of large-scale ecological vulnerability caused by natural and human factors is now one of the most active topics in the ifeld. Taking the Guangxi Xijiang River Economic Belt in southwest China (GXEB) as a case study, we assess ecological vulnerability based on the Vulnerability Scoping Diagram (VSD) model. The indices system is decomposed into three sub objects, ten elements and 25 indicators layer by layer, which included factors from both natural and human ifelds. Results indicate that zones with lower, middle-lower, middle, middle-higher and higher vulnerability account for 11.31%, 22.63%, 27.60%, 24.39%, and 14.07%, respectively. The western and eastern parts of GXEB are more vulnerable than the central part and the mountain and urban areas are of higher vulnerability than the basins and river valleys. Compared with a vulnerability assessment based on natural factors only, it is concluded that human activities indeed cause the transition from naturally stable zones to vulnerable zones. The nature-dominated vulnerable zones are different with human-dominated ones in size and distribution, the latter being smaller, more scattered and distributed in urban areas and their surroundings. About 53%of total construction land is distributed in zones with middle and middle-higher ecological vulnerability;less vulnerable zones should attract construction in the future. Relevant suggestions are proposed on how to reduce vulnerability according to inducing factors. The VSD model has a signiifcant advantage in the quantitative evaluation of ecological vulnerability, but is insufficient to distinguish nature- or human-dominated vulnerability quantitatively.%生态系统脆弱性受到自然与人文因素双重影响。以广西西江经济带为例，采用VSD模型，通过暴露度、敏感性和适应能力分解脆弱性，构建包含自然和人为因素的25指标的评价体系，开展脆弱性评价与分区。结果表明，不脆弱区、一般区、脆弱区、很脆弱区和极脆弱区分别占11.31%、22.63%、27.60%、24.39%和14.07%，东西部地区脆弱性较高，中部地区脆弱性较低；自然因素导致的脆弱区主要分布于东西部山区，人为因素主导的脆弱区分布于中部盆地的城镇及其周边；经济带约53%的建设用地分布于很脆弱区和脆弱区，未来新增建设用地需要重点向不脆弱区和一般区转移。根据分区结果和诱因差异，提出了不同类型区开发与保护的相关建议。