基于GIS的安顺市景观格局空间梯度分析

Spatial Gradient Analysis of Urban Landscape Pattern in Anshun City Based on GIS

随着城市规模日益扩张,人为活动干扰的加剧,景观格局的剧烈变化影响喀斯特山地城市生态系统服务功能,对城市经济社会和自然复合生态系统的可持续发展产生较大的影响。以黔中喀斯特典型山地城市安顺市建成区为研究对象,以2012年和2016年高分辨率遥感图像为主要数据源,基于GIS软件平台,通过建立研究区城市景观类型空间属性数据库,采用景观空间梯度法和景观格局指数法,系统分析“城市双修”和“国家园林城市建设”政策驱动下,安顺市建成区2012年和2016年景观格局的时空动态变化及其梯度特征。结果表明:1)2012-2016年,研究区景观格局发生剧烈改变,城市用地的扩张与耕地缩减耦合,小型斑块数量明显增加,景观破碎化程度加剧。2)随着城市景观向外围扩展,建筑用地优势度先增加后降低,建成区外部缓冲带景观多样性逐渐丰富,受人为干扰强度弱化。3)研究期间,各景观类型交错分布,斑块分布复杂化、不规则,集聚度与连通性逐年下降。

With the increasing expansion of urban scale and the intensification of human interference,the drastic changes of landscape pattern have affected the ecosystem service functions of karst mountainous cities.It has a great impact on the sustainable development of urban economic,social and natural complex ecosystem.Taking Anshun City in Guizhou Province as the research object,the high-resolution remote sensing images in 2012 and 2016 were used as the main data sources,based on GIS software platform,the spatial attribute database of urban landscape types in the research area was established,and the landscape spatial gradient method and landscape pattern index method were adopted.The spatio-temporal dynamic and gradient characteristics of landscape pattern in 2012 and 2016 in Anshun City driven by the policies of‘double urban construction’and‘national garden city construction’were analyzed.The results showed that:1)from 2012 to 2016,the landscape pattern of the research area changed dramatically,the expansion of urban land was related to the decrease of arable land,the number of small patches increased significantly,and landscape fragmentation intensified.2)With the expansion of urban landscape to the periphery,the superiority of building land increased first and then decreased,the landscape diversity of the external buffer zone was gradually enriched,and weakened by the intensity of interference.3)Within the study period,the landscape types interlaced,the patches distribution was complicated and irregular,with the decrease of agglomeration and connectivity.