其在ARC/INFO软件的水文模块环境下，经过数据预处理、流向分析、汇流分析和流域识别等过程，最终自动提取1435个小流域。
Secondly , under the environment of hydrologic model of ARC / INFO software , through DEM pretreatment , flow direction analysis , flow accumulation analysis and watershed recognization , 1 435 small watersheds are extracted .
预流向