Author(s): Christos Katopodis; Paul S. Kemp
Keywords: No Keywords
Abstract: Morphodynamics and aquatic biota (i.e. plants and animals) interact through complex processes, to generate suitable, diverse and resilient habitats. We define morphodynamics in broad terms as the discipline of Earth surface characteristics and evolution which integrates hydrological, geomorphological and geological aspects. This definition is similar, although narrower to that offered by Paola et al. (2006), since we include ecological and biological aspects in Ecohydraulics. Complex physical processes are linked to planforms, longitudinal profiles and cross-sectional geometries in rivers, lakes and deltas and involve the cycling of water, sediment, ice, nutrients, solutes and organic materials in watersheds. Through surface, subsurface or groundwater flow, erosion, transport, deposition and ice conditions, morphodynamics shapes bars, pools, riffles, islands, side channels and other features in waterbodies (Paola et al. 2006; Wohl et al. 2015). Ecological dynamics, commonly understood less clearly, represent the even more complex life processes and food webs, responses by aquatic species and vegetation, populations and communities, as well as suitable habitats characterized by spatial complexity, connectivity and dynamism which meet biota life cycle requirements, enable ecosystem functionality and support biodiversity (Elosegi et al. 2010). Large differences in genetic flow, dispersal and mobility strategies or abilities of aquatic biota populations add another layer to this complexity and needs for more in-depth knowledge and understanding. With such complexities, it is not surprising that large knowledge gaps exist in morphodynamics and ecology, and particularly in the interaction between the two. Although often it is thought that geomorphology sets the template for biological processes (e.g. Vannote et al. 1980), recent studies indicate direct and indirect effects on physical processes from aquatic and riparian vegetation, particularly in the riparian zone (e.g. Gurnell et al. 2012), or even from fish through nutrient enrichment or potential effects on gravel substrates (e.g. DeVries 2012). Such interactions create numerous feedback mechanisms between biotic and abiotic processes, ecology and morphodynamics, generate further knowledge gaps and offer potentially great insights if elucidated though comprehensive studies. Since Ecohydraulics is at the interface between morpho- and eco-dynamics and explores biota and physical interactions, breakthroughs in this interdisciplinary field become very challenging. At the same time, such challenges offer a plethora of opportunities for pioneering research and practical applications for inter- and trans-disciplinary advances in Ecohydraulics.