以典型的秦巴山地城市万源市为例,根据山地生态系统特征,选取土地覆盖类型、高程、地质灾害、生境类型、水土流失、坡度、景观破碎度和生物多样性等8个因子,划分为极敏感、敏感、低敏感和不敏感4个等级,利用AHP确定因子权重,结合GIS空间分析技术,得到综合的生态敏感性空间分布,4个敏感级的面积比分别为8.44%、44.50%、38.31%、8.75%。根据各个因子对生态环境贡献的大小,得到了限制性敏感因子在空间上的分布。生态敏感性分析为城市规划和城市发展用地选择提供了科学依据,减小了城市发展对生态系统破坏的风险。
Taking a typical mountain city (Wanyuan city) in Qinba Mountain area for example, eight sensitive factors for eco-environment are selected based on literatures and characteristic of mountain landscape such as land cover, elevation, geology disaster, habitat type, water and soil loss, slope, landscape fragmental index and biodiversity. Firstly, sensitive factors are classified into four grades, extreme sensitivity, sensitivity, low sensitivity and no sensitivity. Then combined Analytic Hierarchy Process (AHP) and spatial analysis in Geographical Information System (GIS), overall ecological sensitivity is firstly calculated and displayed on space. The area percentages of extreme sensitivity, sensitivity, low sensitivity and no sensitivity are 8.44%, 44.50%, 38.31% and 8.75% respectively. Area with extreme sensitivity mainly distributes in nature protected area, scenic spots and other area with higher elevation, higher slope and high risk of geology disaster, where any exploitive activity should be forbidden. Area with no sensitivity, however, scatters in valley and platform as expanded area of the city in future. Other area with sensitivity and low sensitivity hold total area more than eighty percent of Wanyuan city, in which anthropic activity should be reasonably limited and optimized. Furthermore, Restrictive ecological sensitivity factor in every pixel is determined based on contribution of sensitivity factor to eco-environment. Ecological sensitivity analysis can present a scientific evidence for urban planning and land use and can reduce the risk of ecosystem damage.