摘要
矢量和栅格是GIS应用中两种基本的地学数据格式。与矢量数据相比,栅格数据利于空间建模和空间分析,且是空间尺度分析应用中常用的数据格式。一般来讲,较大尺度的矢量数据,涉及到保密性和知识产权的问题,若将这类矢量数据栅格化后,所得栅格数据由于其空间坐标精度相对降低而更易于实现数据共享。随着地学信息收集技术的不断发展,栅格数据正逐渐成为地学应用主要的数据格式。然而,传统的栅格化是一个伴随有属性信息损失的过程,主要原因在于一个栅格单元区域内存在混合类型。针对现阶段栅格化过程中的这个问题,本文以2005年全国1∶25万土地覆被矢量数据为例,提出了一种在ArcGIS软件环境下,依据"在一个单元格网中,一种土地覆被类型表达为一个GRID图层"的原则,结合POLYGRID命令及其{LOOKUP_TABLE}INFO文件进行土地覆被矢量数据无属性信息损失栅格化的方法。该方法可为相关研究人员在今后处理和分析地理空间数据的工作提供新的思路,以及为空间尺度的应用研究提供有价值的参考。
Vector and raster are two basic formats of geospatial data used in GIS.Raster data are more suitable for spatial modeling and spatial analysis than vector data,moreover,rasterization has efficacy of scaling to some extent,and raster data is the major format used in the application of spatial scaling analysis.In most cases vector data of large scales are subject to information security and intellectual property protection.These data can be shared more publicly because their spatial resolution decreases after rasterization.As the technologies of geospatial information collection improved increasingly,raster data have become the most dominant format of data sources in geosciences.However,traditional rasterizing method is a conversion process accompanied with attribute information loss,the main reason of which is ＂various types existing in one grid＂.In view of current problems in process of rasterization,taking rasterization of land cover data of China at a scale of 1∶250 000 as a case study,this paper puts forward a conversion method based on grid cell,that is on the principle of ＂one land cover category one grid＂,and combines POLYGRID command with its {LOOKUP_TABLE} INFO files in the software environment of ArcGIS,so as to guarantee no information loss in the whole conversion process.Moreover,the study can provide a new insight and a new idea for correlative researchers to deal with and analyze geographical spatial data sets,as well as supply valuable references for the scientific work of spatial scaling analysis.
出处
《地球信息科学学报》
CSCD
北大核心
2010年第3期385-391,共7页
Journal of Geo-information Science
基金
资源与环境信息系统国家重点实验室自主研究课题--地球科学数据质量评价研究
中国科学院地理科学与资源研究所创新三期领域前沿项目(地球信息方法论体系)课题--地学数据空间化误差评价方法及案例研究
关键词
矢量
属性信息无损
栅格化
方法
vector
no attribute information loss
rasterization
method
