Evaluation of influencing of terrain factors on land use change based on improved Index Sum Method

Land use change is the interaction result of human activities and natural environment under social and economic impact. Discovering factors affecting land use change is the hot spot and has very important significance for researches on resources, environment and socioeconomic issues. Terrain directly influences land use change. Therefore, it is crucial to explore the extents of terrain affecting the regional land use changes. In order to explain the interaction of human-land system and provide the basis for sustainable land use, environmental protection and ecological reconstruction, we conducted a research on the performance of terrain factors with regard to land use change. The study aimed to explore the influence extents of terrain factors on regional land use change, so as to provide scientific basis for regional land development and land use spatial structure, direction and mode. In view of the existing problems in the research field, based on the natural conditions, land use characteristics and terrain factors of the study area, we chose 12 evaluation indexes from the macro-terrain factors and micro-terrain factors to establish the evaluation index system. Then, a comprehensive evaluation model of terrain factors influencing on land use change was established based on the improved Index Sum method. Indexes weights were determined by combining Entropy method and Decision Alternative Ratio Evaluation System to overcome the objectivity of the Entropy method and improve the rationality of weight determination of the improved Index Sum method. The influencing extent of terrain factors on land use change in Luanchuan County of Henan Province was evaluated using the established method. The results showed that the influencing extents of terrain factors of evaluation, slope, slope direction, slope length, slope direction variability and surface cutting extent increased from 2005 to 2015, while those of slope variability, plane curvature, profile curvature, elevation variation coefficient, terrain relief and terrain roughness decreased. The change in comprehensive influencing extent of terrain factors on land use change was 0.000 978 and the change rate was 7.06% from 2005 to 2010, which were -0.001 705 and -11.50% from 2010 to 2015, and -0.000 727 and -5.25% from 2005 to 2015. These results showed a tendency of increase-decrease of terrain factors influencing extent on land use change from 2005 to 2015. The evaluation results showed that the terrain factors, as the natural driving factors of land use change, had a decreasing trend of influence extent with the social and economic development, improvement of human technology, rationalization of political and economic structure and environment protection. The results provided the important data reference and scientific basis for regional land use planning, urban construction and ecological environment protection.