科尔沁沙地及其周围地区土地利用变化的时空动态模拟

Simulation of changes in spatial pattern of land use in Horqin desert and its outer area

近几十年来 ,过垦和过牧等不合理的土地利用方式导致科尔沁沙地及其周围地区的土地利用格局发生了显著的变化 ,这些变化对该地区以沙漠化加剧为主要特征的生存环境演变起着重要的促进作用 .根据 2期 (1985年和2 0 0 0年 )土地利用空间图形数据 ,结合地形、土壤、居民点和城镇以及各级道路的分布等驱动因素 ,构建了对近 15年来科尔沁沙地及其周围地区土地利用的时空动态变化进行模拟的CLUE S模型 .结果表明 ,地形、居民点和城镇分布、土壤类型以及乡级道路分布是研究地区土地利用格局分布变化的重要驱动因素 ,构建的CLUE S模型具有较好的时空动态变化模拟能力 ,在基本单元 (15 0 0m× 15 0 0m栅格 )的水平上 ,模型对科尔沁沙地及其周围地区 2 0 0 0年土地利用分布格局模拟的正确率为 91 5 % ,kappa指数是 0 90 .因此 ,该模型可以作为今后探索该地区土地利用时空动态变化前景的重要工具 ,为该地区的环境管理决策提供科学依据 .

Due to over cultivation, over grazing, and other unreasonable land use methods, Horqin desert and its outer area in northern China have experienced significant land use changes, among which the decrease of grassland and agriculture expansion were the most important, which are contributing to severe environmental problems such as extension of desertification. The objective of this paper is to simulate changes in the land use pattern of Horqin desert and its outer area between 1985 and 2000. So, a land use change model, CLUE S, is presented for this simulation. It is based upon an empirical analysis of the spatial distribution of land use types in the study area which takes into account socioeconomic as well as geographical variables. The empirical analysis indicates that a reasonably complete description of land use distribution can be made by including slope, soil types, the distribution of settlement, and proximity to roads as variables. The quantity of land use types from 1985 to 2000 is obtained by linear interpolation of the real area in 1985 and 2000. The result shows that CLUE S is capable of classifying correctly 91 5% of the grid cells, for four categories: cultivated land and settlement (including villages and towns), forest, grassland, unused land and water. Kappa equals 0 90 in the simulation at the basic grid level (1 500 m×1 500 m). It can be concluded that the model, CLUE S, constructed in this study is an important tool to explore near future land use change and is valuable for environmental management in Horqin desert and its outer area.