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.