Introducing uncertainty in the impact assessments of climate change on local scale hydrology

The recently released AR5 report of IPCC confirms that freshwater-related risks of climate change increase significantly with increasing greenhouse gas (GHG) concentrations and that climate change is projected to reduce renewable surface water and groundwater resources significantly in many areas overall the world. This will intensify competition for water among agriculture, ecosystems, settlements, industry, and energy production, affecting regional water, energy, and food security and increase water insecurity. This calls for paradigm shifts in the water management policy and adaptation of water management at different levels (physical technical, social, institutional). However, many barriers for adaptation exists. One of these barriers is related to a poor understanding of possible impacts of climate change at the local hydrological scale, and a poorly characterized uncertainty associated with such impact studies. To improve this, we show how uncertainty can be propagated for assessing hydrological impacts of climate change at the local scale. We illustrate the approach for two catchments of the Mediterranean region - which is considered as a hotspot for climate change – and demonstrate how uncertainty can be decomposed in uncertainty coming from the hydrological model and uncertainty coming from the climate model