An automated method for river sinuosity calculation using QGIS

In all gravel bed rivers the Bed Load Transport (BLT) assumes a fundamental relevance as it is responsible of the river’s morphological configuration. Due to the BLT such rivers, generally, are not straight: even the rivers that are not frankly meandering have its sinuosity. This parameter, therefore, is one of the most important morphometric elements in the definition of the riverbed type, so that according this parameter the rivers (at least one-channel ones) are classified, with all the morphodynamic and sedimentary implications that the classification implies. The calculation of the Sinuosity Index can be considerably simplified thanks to the use of geographic information systems, through the realization of specific tools. On this basis, a QGIS plugin called “RiverMetrics” was created that calculates the sinuosity Index by charting the trend of the index along the Riverbed Axis. The plugin allows you to insert interruptions directly into the graph starting from an evaluation of the variability of the index. These interruptions are used to divide the entire riverbed in homogeneous reaches and to calculate the value of the Sinuosity Index for the specified reach as defined.