结合SOM与动态度方法的土地利用及其时空演变研究

A Study on Spatial-Temporal Changes of Land Use in Combination with SOM and Dynamic Index

[目的]验证结合自组织神经网络(self-organizing map neural network,SOM)与动态度的方法在时间序列土地利用地类与结构的交互分析中的适用性,从多尺度展开土地利用地类及其结构演变分析,为城市土地资源可持续开发和利用提供参考。[方法]基于湖北省黄石市2005,2010,2015年土地利用数据,运用土地利用动态度,分析市域层面地类变化和转移特征,构建SOM模型实现乡镇层面结构空间表达,综合二次聚类和动态度分析整体土地利用演变规律。[结果](1)建设用地著增加,贡献者为耕地、林地、未利用地;耕地持续减少,转换为建设用地和采矿用地与裸地;未利用地大量减少。(2)乡镇级土地利用结构变化趋势以耕地型向城镇/耕地型过渡为主。(3)中部、西部及南部乡镇土地利用变化和缓,东北部乡镇土地利用变化活跃,土地利用结构类型也发生了变化。[结论]SOM与土地利用动态度结合的方法适用于多尺度长时间序列土地利用时空演变综合分析。

[Objective]To verify the applicability of the method that combined self-organizing map neural network(SOM)and dynamic index methods in the analysis of interactions between land use types and structures in a certain period,and to analyze the evolution of land use types and structures from multiple scales in order to provide reference for the sustainable development and utilization of urban land resources.[Methods]Based on the land use data of Huangshi City,Hubei Province in 2005,2010 and 2015,we used the single dynamic degree of land use to analyze the change and transition characteristics of land use types at the city level,and constructed a SOM model to express the spatial distribution of land use structures at the township-level,and explored the overall land use evolution with a method integrated K-means clustering and comprehensive dynamic degree of land use.[Results]①The area of build-up land increased obviously,and they were transformed from cultivated land,woodland and unused land.The area of cultivated land was continuously decreased,as a result of conversions into construction land,mining land and bare land.The area of unutilized land reduced substantially.②The transformation among types of land use structure was mainly from cultivated land to urban/cultivated land.③The central,western,and southern towns had experienced their slight changes in land use;while the towns in the northeast changed significantly,so did its structure.[Conclusion]The method in combination with SOM and land use dynamic index is suitable for comprehensive analysis about the spatial and temporal evolution of land use.