RivWidth: A Software Tool for the Calculation of River Widths From Remotely Sensed Imagery

RivWidth is an implementation in ITT Visual Information Solutions IDL of a new algorithm that automates the calculation of river widths using raster-based classifications of inundation extent derived from remotely sensed imagery. The algorithm utilizes techniques of boundary definition to extract a river centerline, derives a line segment that is orthogonal to this line at each centerline pixel, and then computes the total river width along each orthogonal. The output of RivWidth is comparable in quality to measurements derived using manual techniques; yet, it continuously generates thousands of width values along an entire stream course, even in multichannel river systems. Uncertainty in RivWidth principally depends on the quality of the water classification used as an input, though pixel resolution and the values of input parameters play lesser roles. Source code for RivWidth can be obtained by visiting http://pavelsky.googlepages.com/rivwidth.