泥河沟流域生态敏感性分析评价

为摸清泥河沟流域生态系统在综合治理近30 a后的敏感性，基于GIS与多因子综合评价相结合的方法，对其生态敏感性进行分析评价。结果表明，泥河沟流域生态敏感性总体上表现出沟谷高、塬面低的空间异质性特征，生态系统极度敏感区主要分布于沟谷及沟谷两侧植被盖度低的区域；生态敏感性程度与坡度、起伏度和土壤侵蚀强度呈正相关关系，而与植被覆盖度和人类活动强度呈负相关关系；土壤侵蚀强度和土地利用类型是该流域生态系统最主要的两个影响因素。经过近20 a的自然发展，泥河沟流域生态敏感性得到较明显改善，整体上已处于较低水平，生态环境抗干扰能力增强，趋于更加稳定的状态。研究结果与方法对于重新认识和评价同类小流域生态敏感性及生态环境保护具有一定的参考和借鉴意义。

Integrated Ecological Sensitivity Analysis and Evaluation of Nihegou Catchment

In order to understand the ecological sensitivity of the Nihegou catchment after 30-year successive comprehensive management,the integrated ecological sensitivity was analyzed and evaluated based on GIS and multifactorial comprehensive evaluation.The results showed that,the ecological sensitivity of the Nihegou catchment had certain spatial heterogeneity,which was higher at the gully and lower in the plateau surface as a whole,and the extremely sensitive areas was mainly distributed in the both sides of the valley where had lower vegetation coverage.The ecological sensitivity had either a positive correlation with slope gradient,topographic relief and soil erosion intensity,or a negative correlation with vegetation coverage and the intensity of human activity.Amongest,soil erosion intensity and land use types were the main influencing factors.After nearly 20 years of natural development,the ecological sensitivity of the Nihegou watershed had been significantly improved,and it had been at a relatively low level as a whole.The anti-interference ability of the ecological environment had been enhanced and tended to be more stable.The results and the methods adopted in this paper had a certain referential significance for evaluating the ecological sensitivity,re-understanding ecological environment for similar small catchments.