thalweg

名词 thalweg:

1. the middle of the chief navigable channel of a waterway that forms the boundary line between states
2. a line following the lowest points of a valley

thal.weg

n.Geology （名词）【地质学】
The line defining the lowest points along the length of a river bed or valley.
河流谷底线：延着整条河床或河谷长度，用来界定最低点的线
A subterranean stream.
地下溪流

来源：
German
German
Tal, Thal [valley] from Middle High German tal from Old High German
Tal, Thal [valley] from Middle High German tal from Old High German
Weg [way] from Middle High German wec, weg from Old High German weg * see wegh-
Weg [way] from Middle High German wec, weg from Old High German weg *参见 wegh-