A Set of GRASS GIS-Based Shell Scripts for the Calculation and Graphical Display of the Main Morphometric Parameters of a River Channel

Abstract

For the analysis of river evolution, the use of quantitative parameters can be quite useful in order to assess changes in the channel planform. Among the several parameters proposed by different authors in a number of papers, channel length and width, braiding and sinuosity indexes, and channel lateral shifting are proved to be the most effective ones for a quantitative analysis of river changes. However, the calculation of these parameters is time-consuming, tedious and error-prone, even where made in a GIS environment. This work describes four shell scripts that perform fast and automatic calculation of the morphometric parameters and draw curves showing the variation of the calculated parameters along the entire channel development. The scripts are based on commands of the GRASS GIS free and open source software and, as input, they require a simple vector map containing the essential features of a river channel, i.e. bankfull channel limits and longitudinal and lateral bars.