摘要
在栅格数据模型中进行成本距离分析,栅格单元间可移动方向受限于单元的邻域范围,导致到达目标单元的最短通行路径呈锯齿状,从而高估了到达目标单元的最小累计成本距离。该文引入光在介质中传播的思想,提出一种提高栅格成本距离分析准确性的改进算法:首先,基于单元的邻域关系将成本栅格转换为对应的加权网络模型;然后,采用Dijkstra算法计算源到其他所有单元的最短通行路径;计算过程中保留因单元成本改变而导致的路径偏折,对均质区域中通行路径上的不必要偏折进行及时校正,以减少被高估的行程成本。利用3种典型的成本栅格数据对算法进行验证,结果表明:与传统成本距离算法、细分移动方向方法、后处理校正方法相比,该文提出的改进算法能计算出更为合理和准确的结果。
Cost distance analysis is one of the fundamental functions in geographical information systems(GISs).When applying cost distance analysis based on raster data model,the moveable directions between cells are limited to the selection of neighbouring cells,resulting in the shortest path to the target cell travelling zigzag and the overestimation of the least accumulative cost distance to the target cell.Therefore,this paper introduces the idea of light propagating in the media and proposes an improved algorithm for increasing the accuracy of raster cost distance analysis.Firstly,based on the neighbour relationship among cells,the cost raster is transformed into a weighted network.Then,Dijkstra algorithm,which is effectively implemented by using a minimum heap,is adopted to calculate the shortest path from the source to every other cell.During the calculation,deflections on the shortest path caused by the changes in the cost of cells are retained,while unnecessary bends along the travel path in the homogeneous cost area are constantly corrected to reduce the overestimated travel cost.The feasibility and accuracy of the proposed algorithm are verified using three typical kinds of cost raster data.The experimental results indicate that the proposed algorithm can generate more reasonable and accurate results than three other commonly used methods,including conventional cost distance algorithm,subdividing moveable direction method,and correcting in the post-processing method.
作者
陈雅茜
高亦远
葛荣存
谈俊忠
佘江峰
CHEN Ya-qian;GAO Yi-yuan;GE Rong-cun;TAN Jun-zhong;SHE Jiang-feng(Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology,Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources,School of Geography and Ocean Sciences,Nanjing University,Nanjing 210023,China)
出处
《地理与地理信息科学》
CSCD
北大核心
2020年第3期18-24,共7页
Geography and Geo-Information Science
基金
国家自然科学基金面上项目(41871293,41371365)。
