Wide rivers and water areas

Wide Rivers and Water Areas

River Garonne -SPOT channel XS3- (©CNES 94).

$\begin{figure}\begin{center}\epsfysize=9cm\epsfbox{/home/pocquet/LEONARDO/REGIS/garonne.ps}\end{center}\end{figure}$

Wide rivers have the aspect of very broad linear elements and are comparable to surface elements like water areas. Their properties are the following:

Radiometry	Radiometric variations are weak and texture is homogeneous. On channel SPOT-XS3, water stands out clearly from its environment, and appears very dark.
Geometry	A river follows a decreasing weak slope. A water area is located in an area of constant altitude or in a depression.

IRIT-UPS