基于RS与GIS的生态用地评价——以辽宁省大洼县为例

生态用地评价是当前生态环境保护与土地利用规划领域重要的研究内容。本文根据研究区自然条件、社会经济状况、土地利用特点和生态保护要求, 借助RS和GIS技术, 在建立基于生态服务功能的生态用地分类体系的基础上, 从生态服务功能和生态敏感性2个方面选取合适的生态用地评价指标, 采用层次分析和专家咨询相结合的方法确定评价因子权重, 合理划分评价单元, 采用指数和法对辽宁省大洼县生态用地进行了定量评价。结果表明, 大洼县生态用地划分为禁止开发生态用地、限制开发生态用地和可适当开发生态用地3个类别。其中, 禁止开发生态用地面积为14 695.97 hm², 占生态用地总面积的27.13%; 限制开发生态用地面积为25 185.49 hm², 占生态用地总面积的46.50%; 可适当开发生态用地面积为14 281.84 hm², 占生态用地总面积的26.37%。这3种生态用地类型有其自身特点, 在土地利用开发过程中应采取相应的生态保护措施。研究结果将为区域生态用地保护、生态环境与人地关系的改善以及新一轮土地利用规划修编提供重要的数据参考与科学依据。

Evaluation of ecological land based on RS and GIS: A case study of Dawa County, Liaoning Province

With increasing calls for environmental quality in recent years, "ecological land" emerged as a specific term in related government documents on land-use planning and environmental protection. This term was put forward to forge a harmony among the development of natural resources, human society and ecosystem. Ecological land is a kind of land with significant ecological services that are crucial for directly/indirectly protecting regional ecological environment and improving regional man-land relationship. In land-use planning, ecological lands with significant eco-service functions were protected. This avoided possible regional eco-environmental issues at certain levels of eco-security, protected regional eco-environments and improved man-land relationship. As such, interests have grown in ecological land evaluations, argued as an important phenomenon in the domain of ecological and environmental protection and land-use planning. Based on natural conditions, socio-economic status, land-use characteristics and ecological protection requirements of the study area, a classification system of ecological land according to eco-services was constructed. On the basis of the system, an ecological land evaluation index system was established. The weights of the evaluation factors were calculated using the AHP (Analytic Hierarchy Process) approach and expert knowledge. The evaluation units were divided and then the ecological land of Dawa County was evaluated using the weighted exponent approach based on RS and GIS. The results showed that the ecological land of Dawa County was classified into three categories - forbidden land development, restricted land development and optimized land development. The ecological land areas of forbidden development, restricted development and optimized development were 14 696 hm², 25 185 hm², and 14 282 hm²; accounting for 27.1%, 46.5% and 26.4% of the total ecological land respectively. Each of the three types of ecological land had its unique characteristics that required protection by adopting corresponding measures. This study will provide data-driven decision-making for regional ecological land protection, improve ecological environment, coordinate man-land relationship and revise land-use planning.