宁夏限制开发生态区生态敏感性综合评价与保护对策

Eco-sensitivity Analysis and Protection in the Restricted Development of Ecological Zones,Ningxia Hui Autonomous Region

以乡镇为基本研究单元,针对宁夏限制开发生态区存在的主要生态环境问题,选取土壤侵蚀、土地沙漠化作为评价因子,运用GIS技术在单因子评价的基础上,采用多因子综合评价的方法,对宁夏限制开发生态区生态敏感性进行综合评价。结果表明:(1)研究区内各乡镇均存在生态敏感性问题,生态敏感程度分为轻度敏感、中度敏感、高度敏感、极敏感4个等级,且94.34%的面积属于中度以上敏感性。(2)生态敏感性的空间分布特征为:位于中部干旱半干旱风沙区的各乡镇,主要的生态问题是土地沙漠化;位于南部黄土丘陵沟壑区的各乡镇,主要的生态环境问题是土壤侵蚀。(3)以市(县)为基本空间单元所得的评价结果,没有考虑县内各区域之间的差异性,研究结果可操作性较差,以乡镇为基本空间单元所得的评价结果因均质性较好,研究结果具有较强的针对性和可操作性。

As a special type of main functional areas in China,restricted exploitation area is one of the ecologically fragile,long-term underdeveloped areas in China.Also,it is a special complex area among China′s ecologic security,food security,and homeland security.So,it is one of the hot issues of academic concern.On the basis of analyzing and summarizing the relevant literature,with the township as the basic units,based on the main eco-environment problems in the Restricted Development Area of Ningxia Hui Autonomous Region,soil erosion and land desertification are chosen to carry out single factor and integrated appraisal of eco-sensitivity with GIS technology to analyze the eco-sensitivity in the Restricted Development Area of Ningxia Hui Autonomous Region.The results show that:(1)the major ecological problems in the study area are land desertification and soil erosion,spatial differentiation is significant.All the townships in the study area are ecological sensitivity,the townships in the central arid semiarid areas with sparse vegetation,strong sunshine,very little precipitation,the major ecological problems are land desertification;the townships in the southern loess hilly region with rapidly terrain slope,soil matrix loam,barren land,water erosion,the major environmental problems are soil erosion,there are four grades of eco-sensitivity,namely slight sensitive,moderately sensitive,highly sensitive,extremely sensitive,and 94.34%of the area belongs to the moderately sensitivity;(2)extremely sensitive and highly sensitive areas are fragile ecological environment area,system stability,development costs and repair costs are high,should be used as a key protection areas,and large-scale,highintensity of industrialization and urbanization development activities should be prohibited;moderately sensi-tive areas are more vulnerable which have a certain amount of resistance to outside interference,within the scope of the ecological carrying,moderate development activities can be engaged;mildly sensitive and nonsensitive areas can be used as a suitable development zone,which allows a certain scope of industrialization and urbanization activities.