Characterizing fluvial systems at basin scale by fuzzy signatures of hydromorphological drivers in data-scarce environments

Fluvial geomorphology has been increasingly recognized as a key component of modern river basin management. River morphological processes resulting from the interaction of natural and anthropogenic forces shape physical habitats, affect river infrastructures, and drive freshwater ecological processes. Nevertheless, geomorphic information or process-based assessments of fluvial systems on large scales (catchment, regional) are still scarce. This is especially the case in less developed countries where fluvial geomorphic assessments and data collection are not common routine due to a lack of location-specific expertise and of the resources necessary to collect, store and process hydromorphological information. In this paper we propose a new, scalable and globally applicable framework to analyse and classify fluvial systems in data--scarce environments using freely available remote--sensing information and several in--situ hydrological time--series. Key component of the framework is a fuzzy classifier through which individual river reaches are characterized by different fuzzy signatures of hydromorphological drivers. We demonstrate the framework on the Red River Basin, Vietnam, where human--induced alterations in hydro-morphological processes acutely endanger local livelihoods, while hydromorphological information is very limited at present. The classification obtained from our framework is then used to interpret time--series of high--resolution satellite images where it successfully identifies breakpoints as well as continuous downstream change in channel patterns and morphology. For the case study, we also provide evidence that the fuzzy hydromorphologic signatures can be applied for predictive modelling of fluvial forms and dynamics –- potentially a first step towards quantitative predictive models of HYMO dynamics to inform large—scale decision—-making.

BIZZI Simone;  CASTELLETTI Andrea;  SCHMITT Rafael; 

2014-11-26

ELSEVIER SCIENCE BV

JRC84155

0169-555X,   

http://www.sciencedirect.com/science/article/pii/S0169555X1400107X,    https://publications.jrc.ec.europa.eu/repository/handle/JRC84155,   

10.1016/j.geomorph.2014.02.024,