Uncertainty assessment of hydrological impacts of climatic change in small mediterranean catchments

The assessment of uncertainty associated with the hydrological impacts of climate change is of fundamental importance for sustainable water resources management. However, both hydrological and climate models are prone to uncertainties that interact and propagate in a complex chain. Quantifying and characterizing these uncertainties is a challenge particularly in Mediterranean catchments identified as “a hot spot” for climate change and variability. Results from a conjunctive use of a hydrological model underpinned with multi-climate models indicate that uncertainty arising from hydrological model parameter is important and should be routinely considered in climate change impact studies. The decomposition of modelling uncertainty reveals that climate models uncertainty prevails over hydrological parameter uncertainty during the wet period, whereas during the dry period the latter uncertainty source becomes more important. Despite these uncertainties climate change projection for 2050s is likely to induce severe changes in flow regime and general shortage of the available water resources in Mediterranean catchments. Other potentially important uncertainty sources were neglected in this work and, thus, the estimated uncertainty ranges are likely smaller than the overall uncertainty associated with climate impacts on catchment hydrology. This highlights the needs for complete assessment of all uncertainty sources in the future while investigating the hydrological impacts of climate change projections in Mediterranean catchments.