Aiming at the bottleneck of traditional extraction method of topographic factor on soil erosion in processing massive data, this paper proposed a method based on MapReduce. This method combined the parallel computing model MapReduce with the revised universal soil loss equation(RUSLE). The method established the flow relationship search tree by the principle of steep slope and the B+ tree, and represented the correlation of topographic data; The method used the MapReduce model to search flow path and converge grid instead of the traditional forward and backward traversal algorithm, and solved the efficiency of the flow accumulation and slope length calculation in topographic factor calculation. The experimental results show that for the extraction of topographic factor from massive digital elevation model, the method can effectively improve the extraction efficiency in the range of the allowable accuracy.

[2019-06-05] Printed Article /doc/2017.12.0806/v2