A Matlab script for the morphometric analysis of subaerial, subaquatic and extra-terrestrial rivers, channels and canyons

Morphometric characteristics play an important role in the classification and modelling of fluvial systems. With increasing numbers of detailed surveys of subaquatic canyon and channel systems in lakes, reservoirs, oceans and extra-terrestrial systems, previous research has repeatedly tried to draw parallels between poorly understood subaquatic and extra-terrestrial systems and much studied subaerial fluvial systems. Often, these studies only considered a few morphometric characteristics (e.g., bed slope, bankfull width, centreline radius in bend apices, bankfull depth), because an efficient tool for the determination of these characteristics was missing. To address this, we present a simple-to-use Matlab script for determining the most important morphometric characteristics of subaerial, subaquatic and extra-terrestrial rivers, channels and canyons. The only inputs required are the levee or bank crests that enable the definition of a centreline as the basis of a channel-centred curvilinear reference system and the calculation of planform characteristics (e.g., bankfull width, gradually varying curvature, sinu-osity). If available, digital elevation data of bathymetry or topography are converted into the same channel-centred curvilinear reference system, thus enabling the determination of the longitudinal bed slope and further morphometric characteristics in cross-sectional planes (e.g., bankfull depth, cross-sectional area, and slopes of banks or levees). The script is applied to a subaquatic canyon in Lake Constance as an example. This script provides an efficient tool for analysing the ever-growing amount of digital elevation models (DEMs) in subaerial, subaquatic and extra-terrestrial rivers, channels and canyons. The reported script is particularly appropriate for the poorly understood subaquatic systems and will contribute to the understanding of the largest canyon and channel systems on our planet.

Automated summary

Morphometric characteristics play a crucial role in the classification and modeling of fluvial systems. A simple-to-use Matlab script is presented for determining the important morphometric characteristics of subaerial, subaquatic and extra-terrestrial rivers, channels, and canyons. This script provides an efficient tool for analyzing digital elevation models (DEMs) and will contribute to the understanding of poorly understood subaquatic systems and the largest canyon and channel systems on Earth.