To plug‐in or not to plug‐in? Geomorphic analysis of rivers using the River Styles Framework in an era of big data acquisition and automation

Abstract

In an era of big-data acquisition and semiautomation of geomorphic river surveys, it is timely to consider how to better integrate this into existing and widely used conceptual frameworks and approaches to analysis. We demonstrate how Stage 1 of the River Styles Framework, which entails identification and interpretation of river character and behavior, patterns and controls, can be used as a "powerboard" into which available, developing and future semiautomated tools and workflows can be plugged (or unplugged). Prospectively, such approaches will increase the efficiency and scope of analyses, providing unprecedented insights into the diversity of rivers and their morphodynamics. We appraise the role of human decision-making in conducting expert-manual analyses and interpretations. Genuine integration of big-data analytics, remote-sensing based tools for semiautomated river analysis with expert-manual interpretations including field insights, will be an essential ingredient to fully exploit emerging computational and remote sensing technologies to advance our understanding of river systems, to translate information into knowledge, and raise the standards of practice in river science and management.

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

“…The real usefulness of such data is evident indeed when studying the GLOF dynamics. As regards planform typology, we defined a stretch as "sinuosity-confined" whenever the curvilinear line linking flexus of the active channel envelope axis lies somewhere outside the valley bottom (VB), i.e., the channel follows the valley bottom axis of a sinuous valley setting with absent or isolated floodplain pockets (sensu Fryirs and Brierley, [40]).…”

Application of globally available, coarse‐resolution digital elevation models for delineating valley bottom segments of varying length across a catchment

“…Furthermore, we recommend that the user verifies the modelled valley bottom output using the hillshade raster, aerial imagery base maps and fieldwork. While the modelled approaches are useful for semi-automating the derivation of the valley bottom, which would be a time-consuming task if performed manually, a human eye is still needed to validate the final output (Fryirs et al, 2019).…”

“…Accurate delineation of valley bottom extent and valley bottom segments is often the first set of analyses undertaken for the hydrological and geomorphic analysis of rivers (Gallant and Dowling, 2003;Limaye and Lamb, 2016;Fryirs et al, 2019;O'Brien et al, 2019). Valley bottom extent is defined as the zone of contemporary fluvial processes and comprises active channel(s) and active floodplain but does not include other features that may occur within a valley, such as terraces and fans (Fryirs et al, 2016).…”

“…With the advent of LiDAR technology and photogrammetry, very fine-resolution DEMs-ranging from a few centimetres to metre raster cell size-are progressively becoming available. The availability of such data has enabled more accurate hydro-logical and geomorphic analysis of rivers (Cavalli et al, 2013;Fryirs et al, 2019;Piégay et al, 2020). However, there are still many places in the world where high-resolution DEM data is not yet readily available.…”

Let the Rivers Speak

“…In Aotearoa, where lived realities already inform legislative, scientific and technical endeavours, there is an opportunity to recognise that each and every river is a living community with its own hauora, mauri and mana, where water, land, plants, animals and people are inextricably entangled, shaping each other across the generations in kin-based exchanges. At the same time, automated monitoring and measurement procedures, alongside ethnographic inquiries, present unprecedented capacities to tell the stories of each river, recorded through systemspecific forms, rates and patterns of adjustment, and the study of long-run relationships and interactions of these life forms at the catchment scale (Brierley et al, 2013;Fryirs et al, 2019).…”