并行化多流向策略的栅格河网提取算法
Raster River Networks Extraction Based on Parallel Multiple Flow Direction Algorithms
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摘要: 流域栅格河网提取是数字地形分析的一个重要应用。为减少数字高程模型(DEM)预处理而产生的伪河道及平行河道,提出基于并行化多流向策略的栅格河网提取算法。通过水流传输矩阵模拟水量的自然流动过程,可直接应用于原始DEM。从河网空间形态和算法运行效率两方面与串行MFD算法、R&N算法及D8算法进行对比,结果表明,多流向策略得到的河网与实际地形形态更加吻合,使用并行策略后,算法的效率比也较其他算法有明显提升。Abstract: Watershed raster river network extraction is an important application of digital terrain analysis applications.A parallel algorithm based on multiple flow direction is put forward in order to reduce pseudo channels and parallel channels which are produced by DEM pretreatment.It simulates the overland flow and uses a more elaborate water transfer model that is inspired by the natural behavior of water on unprocessed DEM. The main advantages of parallel MFD algorithm are put forward on two fronts: the space form of river networks and the efficiency of the algorithm.The experimental results show that the river network of MFD algorithms more aligned with the actual landform tallies.The efficiency of the parallel algorithm is superior of the serial algorithm,R&N algorithm or D8 algorithm.
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