The project is primarily supported by EVS research laboratory, and mainly focussed on the development of an airborne acquisition strategy to characterise river temperature with thermal infrared (TIR). It has been developed over the last 10 years and highly supported and funded by the Rhône Mediterranean Water Agency, in charge of implementing the WFD in the Rhône district, within a research partnership with ZABR (iLTER – Rhône Basin) and the Integrated Watershed Doctoral School EUR H2O’Lyon. We received additional funding from local practitioners allowing the survey of a large range of rivers and conditions (Département des Hautes Alpes, Fédération de pêche de l’Ardèche, Plan Loire, Parc Naturel Régional du Haut Jura, Parc Naturel Régional du massif des Bauges, Communauté d'Agglomération Privas Centre Ardèche). Le lab is currently developing a partnership with a private company SCIMABIO Interface to transfer technical knowledge and acquisition protocols. Several people have been involved since 2010, mainly one PhD (V. Wawrzyniak) and one Post-doc (Baptiste Marteau), several academics (Hervé Piégay, Pascal Allemand, André Chandesris, Flavie Cernesson Florentina Moatar and Zahra Thomas) and GIS engineers (Kristell Michel and Lise Vaudor). A partnership is also developed with Belgium (Univ. Liège Agro-Bio Tech Gembloux: Adrien Michez and Blandine Georges) and India (IIT Varanasi: Shishir Gaur, Anurag Ohri and Nilendu Das.
Several main issues have been explored: Develop a normalised procedure to acquire airborne TIR images and field validation data; Establish a typology at regional scale of cold patches within a large range of hydroclimatic and river pattern conditions; Detect karstic sources and hyporheic exchanges at the riverscape scale; Detect cold patches in braided rivers and identify indicators from archived airborne photos to identify potential “hot spots” with cold patches at a regional river network scale, and potential changes through time due to human pressure on water resources; Evaluate thermal effects of weirs and riparian canopy on lowland rivers and predict risk of temperature warming at network scale; Assess water temperature rising in by-passed reaches; Evaluate groundwater delivery effect and riparian canopy on mean water temperature; Develop a protocol to assess potential effects of gravel replenishment (restoration) on cold patch restoration; Develop technical approach to detect homogenous river reaches in term of temperature pattern allowing the identification of reach-scale thermal regime (thermal longitudinal profiling).
Transfer technical knowledge and acquisition protocol to a private consultant to respond to river managers demand; Develop new perspectives in river corridor characterisation and diagnosis (aquatic plant mapping, water stress of riparian vegetation) using the airborne TIR tool.
A technical guideline (in French) will be published early 2022. It is already written and presently shared with stakeholders for final validation.