县域土地利用细碎度综合度量与空间分异研究——以江苏省东海县为例

CONSOLIDATED QUANTITATIVE RESEARCH ON LAND FRAGMENTATION AND ITS SPATIAL VARIATION AT COUNTY SCALE——A CASE STUDY OF DONGHAI COUNTY,JIANGSU PROVINCE

土地细碎化是与土地规模经营理念相背离的一种土地形态,细碎化的土地经营模式会造成土地利用效率下降、粮食减产以及景观美观度降低等一系列问题。目前,土地细碎化程度的衡量多通过细碎度表征,但尚无统一标准,且主要针对农用地。以江苏东海县为例,首先结合景观指数与主成分分析,分别计算耕地、基础设施用地、居民点用地以及生态用地的细碎度,再通过系统聚类,分析不同地类细碎度组合的地域分异特征。结果显示:不同用地类型的细碎度是自然、社会经济的综合影响结果,耕地细碎度与居民点细碎度有着较显著的正相关关系,与生态用地细碎度有着较显著的负相关关系,基础设施用地细碎度和居民点细碎度存在一定的正相关关系,与生态用地细碎度存在一定的负相关关系,土地细碎度基于不同自然、社会经济条件,其分区也有着特定的区位特征。探讨不同用地类型细碎度间的关联性及空间分异特征可以为土地利用、经济发展以及景观改善等提供科学的引导。

Land fragmentation is a land pattern that deviates from scale land management. The business pattern of land fragmentation would result in decrease of land use efficiency, grain production and landscape esthetic,therefore, the research of land fragmentation has become a focused issue in land planning and agricultural industry areas. At present, there is not yet an unified measurement standard towards land fragmentation,and the degree of land fragmentation could be generally described by fragmentation index. What is most limited is that the land fragmentation mentioned is mainly aimed at farmland and ecological land, construction land is not taken into consideration. This paper took Donghai County in Jiangsu province as an example, used data of different land use types that extracted from present land-use map in 2010, and converted the data to raster format with 10 m resolution to calculate the landscape index of each land use types. 7 landscape indexes from different aspects were chosen to measure the fragmentation degree at last. By taking the method of principal component analysis, the paper calculated the comprehensive fragmentation indexes of cultivated land, infrastructure land, residential land and ecological land. Furthermore,the cluster analysis was performed to investigate the spatial variation of fragmentation of each land type. From all of above analysis, the paper drew the conclusion that the fragmentation of each land use type was influenced by both natural and social-economic conditions, among which natural conditions were topography, hydrology, resources, and social-economic conditions were the level of economic development, leading industry, transportation and so on. Meanwhile, there were correlations among different kinds of land use types. For the reason of cultivating convenience, the distribution of cultivated land was similar to residential land. Thus there was a remarkable correlation between fragmentation of cultivated land and that of residential land, and the distribution of residential land could further affect that of infrastructure land. The main reason that a negative correlation was observed between fragmentation of cultivated land and ecological land was the integrity conservation of ecological land. Influenced by social-economic conditions, the distribution of infrastructure land was rather complicated. There was negative correlation between fragmentation of infrastructure land and that of ecological land. In addition, the fragmentation regionalization in Donghai County conducted a specific regional characteristic. The fragmentation of all land use types showed an unitarity in some aspects,while some special areas with different properties conducted a specific fragmentation layout. Studying correlations among different kinds of land use types and their spatial variation could provide scientific guides towards land use policy making, economic growth, landscape improvement and so on.