基于主控要素的生态地质脆弱性评价--以四川省西昌市为例

Eco-geological vulnerability assessment based on major controlling factors:A case study of Xichang City,Sichuan Province

为了给西昌市生态保护修复提供依据,对其生态地质脆弱性做出评价。在生态地质调查、综合研究的基础上,选取了10项影响西昌市生态地质脆弱性的主要因素,构建了评价指标体系;在地理信息系统(geographic information system,GIS)的支持下,采用改进后的层次分析法,对西昌市开展了生态地质脆弱性评价。结果表明:西昌市生态地质较为脆弱,虽然没有极脆弱区,但中度脆弱—高度脆弱达50.14%。不脆弱与轻度脆弱区主要集中于安宁河谷和邛海盆地,中度脆弱—高度脆弱区域主要集中在西昌市西部的牦牛山一带和东南部的螺髻山一带;全市可划分为5个生态地质脆弱性分区,包括2个生态地质轻度脆弱区--安宁河谷生态地质轻度脆弱区(Ⅰ)和大箐生态地质轻度脆弱区(Ⅱ),1个生态地质中度脆弱区--巴汝—马鞍山生态地质中度脆弱区(Ⅲ),2个生态地质高度脆弱区--螺髻山西坡生态地质高度脆弱区(Ⅳ)和牦牛山生态地质高度脆弱区(Ⅴ)。对于不同的生态地质脆弱性分区,应实行不同的生态保护修复方案与开发建设措施。

The eco-geological vulnerability assessment of Xichang City, Sichuan Province was performed in this study to provide bases for the ecological protection and restoration of the city. Firstly, an assessment indicator system was constructed, for which 10 major influencing factors of the eco-geological vulnerability in Xichang City were selected according to the eco-geological survey and comprehensive research. Then the eco-geological vulnerability assessment of Xichang City was conducted using the improved analytic hierarchy process(AHP) and the geographic information system(GIS). The results are as follows. Xichang City suffers from vulnerable eco-geology. The areas with moderate-high eco-geological vulnerability account for 50.14%, although no areas suffer extreme eco-geological vulnerability. The areas not suffering eco-geological vulnerability and those with slight eco-geological vulnerability are concentrated in the Anning River valley and the Qionghai Lake Basin, while the areas with moderate-high eco-geological vulnerability are mainly distributed in the Maoniu Mountain area in the western part of Xichang City and the Luoji Mountain area in the southeastern part of the city. Overall, the whole city includes five areas with eco-geological vulnerability, namely two areas with slight eco-geological vulnerability in the Anning River Valley(Ⅰ) and Daqing(Ⅱ), one area with moderate eco-geological vulnerability in the Baru-Ma’anshan area(Ⅲ), and two areas with high eco-geological vulnerability on the western slope of the Luoji mountain(Ⅳ) and in the Maoniu Mountain(Ⅴ). Different ecological protection and restoration schemes and different development and construction measures should be implemented for different eco-geologically vulnerable areas in the city.