secondary stream meaning in Chinese

次级河
第二股气流
二次流

Based on the change of the traditional opinion about controlling the water environment of river , the water quality contamination status of the secondary streams in the three gorges reservoir is analyzed
摘要本文基于传统工程治理河流理念的转变，对三峡库区次级河流整治中存在的问题进行了分析。
Combined with the new theories , ideas and technologies which dealing with the water pollution , countermeasures are brought forward for river pollution control and remediation in the secondary streams of the three gorges reservoir
并结合国内外治理河流的新观念、新技术、新思路，提出了三峡库区次级河流的整治对策。