This paper adopts watershed transform to segment those images, but this method easily products the over segmentation which results in the edge line buried in disorderly watershed line.

Recognising that global warming will make any line based on the watershed of a glacier temporary, the understanding with Austria has for the first time introduced the concept of a movable border.

The distinctive position of the Huaihe river as a natural watershed within the four major river system made it more qualified as the dividing line between the south and the north.