Watershed lines (e.g. the continental divide) mark the

boundaries of catchment regions in a topographical map.

The height of a point on this map can have a direct

correlation to its pixel intensity. WIth this analogy,

-Watershed lines (e.g. the continental divide) mark the

　　　　　　　　　 boundaries of catchment regions in a topographical map.

　　　　　　　　　 The height of a point on this map can have a direct

　　　　　　　　　 correlation to its pixel intensity. WIth this analogy,