The main objective of MorphHab is to analyse the role of morpho-sedimentary dynamics in the characterization and evaluation of river physical habitat. The project addresses the need to characterize the physical habitat taking into account its dynamic nature, both spatially and temporally. The starting point of the investigation is the precise identification of the cause-effect relationships between these dynamics and the generation of fluvial habitat, and the constraints posed by water physico-chemical characteristics. The final point is to establish advanced criteria for adaptive management of river systems that contribute to improve and maintain their ecological status in an efficient and lasting way. This study offers the necessary bases for the characterization of the processes responsible for the generation and maintenance of river habitat from an integrated vision over time and, at the same time, spatially distributed, through monitoring, modelling and experimentation activities. Specifically, we study the role of i) the topography of the channels, ii) the morpho-sedimentary units and bed-structure, iii) the lateral and longitudinal (hydrological, hydraulic and sedimentary) connectivity, and iv) the contribution of water and sediment from tributaries, as key aspects that condition habitat availability. The specific objectives are 1) To analyse the spatio-temporal variability of habitat availability in relation to morpho-sedimentary dynamics, in natural reaches of mountain rivers and in reaches under multiple impacts (e.g. gravel mining, rip-rapping, hydropeaks); 2) To analyse the alterations and deficiencies of morpho-sedimentary units, structural elements (boulders, blocks) in the channel and its topographic connectivity, and their effects on habitat availability; 3) To determine criteria for the implementation of morpho-sedimentary units and structural elements that enhance connectivity, altogether necessary to promote favourable hydraulic-sedimentary conditions for self-regeneration of bio-physical processes; 4) To establish advanced criteria to improve the use of hydrobiological methods based on the quantification of the physical habitat of natural reference communities and for the calculation of ecological and maintenance flows, both elements that are contemplated in the current hydrological planning; and 5) To establish advanced criteria towards an efficient and sustainable adaptive management of river systems in order to improve and maintain their ecological status. The practical application of the project findings will allow recognizing what type of structure and spatial organization of the channel explains more and better the availability of habitat; have objective criteria to select the most representative section of the river and the time of year to carry out the physical characterization with the purpose of determining the available habitat; and obtain more stable and consistent habitat results useful for the calculation of ecological and maintenance flows, the evaluation of environmental impact of hydraulic works, and the design of measures of introduction, repopulation, elimination or conservation of aquatic species; altogether with a direct impact on the current conservation and rehabilitation criteria used by hydrological managers.

Keywords: physical habitat, morpho-sedimentary dynamics, mountain rivers, impacts, adaptative management, ecological status, River Basin Management Plans.