A Computer Aided Approach for River Styles—Inspired Characterization of Large Basins: The Magdalena River (Colombia)

Abstract

This paper addresses the geomorphic characterization and classification of large rivers in a framework of scarce information. This is inspired by the River Styles Framework with some modifications that make the process more straightforward and accessible to practitioners and more applicable to large basins, while reducing the subjective, expert-based inputs, as the process is now more systematic. To this aim, it utilizes innovative criteria and some computer-aided procedures and tools based on GIS, Excel and Python. This approach sheds light on the character and the behavior of rivers, which is key to informing planning, management and restoration. The application to the Magdalena River (Colombia) illustrates the characterization and classification process and the type of results, which ultimately highlight the great geomorphic diversity of that river. The process is applicable to many other rivers worldwide.

A Systematic, Automated Approach for River Segmentation Tested on the Magdalena River (Colombia) and the Baker River (Chile)

“…It is quite evident that no further subdivision would bring in additional light regarding its character: the whole reach is a partly confined, sinuous one. This situation is emblematic of several other reaches (T40, 39,38,37,35). Figure 11.…”

“…Its VB axis is about 1400 km long, while the river itself is slightly longer. A segmentation exercise with this magnitude requires time-consuming elaborations and may lead to identifying many diverse typologies (Nardini et al [37]). In the original study by Nardini et al [37], the core attributes are planform type, bed material texture, and stream surface (as a substitute of bed morphology, as this is invisible in the murky waters of the Magdalena).…”

“…A segmentation exercise with this magnitude requires time-consuming elaborations and may lead to identifying many diverse typologies (Nardini et al [37]). In the original study by Nardini et al [37], the core attributes are planform type, bed material texture, and stream surface (as a substitute of bed morphology, as this is invisible in the murky waters of the Magdalena). It must be reminded that these attributes have been estimated at a preliminary, rough level, as available information is overall scarce and incomplete (see the original GeoMagda project report for details: Nardini et al [38]).…”

“…Let us now consider the partly confined stretches (Table 1) to assess whether these should have been further split. According to the characterization described in (Nardini et al [38] and Nardini et al [37]), conclusions are as follows: Table 1. Magdalena case study: partly confined reaches of the Magdalena river according to the River Styles analysis performed on the segmentation obtained with the proposed procedure in Nardini et al [37,38].…”

“…According to the characterization described in (Nardini et al [38] and Nardini et al [37]), conclusions are as follows: Table 1. Magdalena case study: partly confined reaches of the Magdalena river according to the River Styles analysis performed on the segmentation obtained with the proposed procedure in Nardini et al [37,38]. T1 T3 T4 T6 T13 T23 T24 T25 T27 T28 T29 T30 T32 T33 T34 T35 T37 T38 T39 T40 T43 Starting from the upstream reach T43, Figure 11a shows the pattern of the active channel within the VB and the type of confinement (visible from the position of the active channel within the VB corridor).…”