Future Hydrology of Alpine Rivers of Italy: the Interreg Project GE.RI.KO Mera

EGU2020-20231 https://doi.org/10.5194/egusphere-egu2020-20231 EGU General Assembly 2020 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License.

Future hydrology of Alpine rivers of Italy: the Interreg project GE.RI.KO Mera

Daniele Bocchiola, Francesca Casale, Leonardo Stucchi, and Giovanni Bombelli Politecnico di Milano, DICA, Milano, Italy ([email protected])

We present preliminary results in fulfilment of the IT-CH Interreg project “GE.RI.KO Mera”. The main aim of the project is to create a common strategy for the management of common water resources, in the transboundary Mera catchment, laid for ¼ in Switzerland, and for ¾ in Italy. Mera river sources in the Maloja mountains of Switzerland, crosses the Bregaglia valley, and reaches Valchiavenna of Italy, then receiving Liro river’s water, and then flows into the Novate-Mezzola lake, and in Como lake soon after.

This area is particularly important, for hydropower production, and large exploitation of water resources for fishing, and leisure in general.

Bregaglia valley carries large sediment load in the river, which affect aquatic species during floods, and lead to progressive filling of hydropower basins, and sediment accumulation along the river, with potential for increased flood risk, and often need for removal. GE.RI.KO project aims to jointly manage the transboundary waters of the Mera river to i) limit alteration of riverbed morphology and erosion, ii) avoid biodiversity loss, and iii) reduce flood risk along the river.

Here we report modelling of hydrology of this high altitude basin with Poli-Hydro model, and an analysis of future climatic conditions in the area of Valchiavenna for different Representative Concentration Pathways (RCP). We use several RCPs from IPCC’s AR5/6, and several GCMs, for a grand total of 21 climate scenarios (plus local downscaling) to force the Poli-Hydro model to depict future hydrological scenarios in the area.

We report main potential hydrological variations, and depict main challenges for water management in the Mera catchment under future scenarios, to be explored by the GE.RI.KO project.