By Gary Thomas
Noora Veijalainen, a hydrologist working at the Finnish Environment Institute, applied a number of climate scenarios and hydrological models to evaluate the effects of climate change on floods, discharges and water levels in Finland.
The latest results can be utilized as background data for adjusting to the climate change, particularly with regards to flood risk management and lake regulation. The doctoral thesis will be presented on June 1, 2012 at the Aalto University in Espoo, Finland for public examination and debate.
According to Veijalainen, the research demonstrates that seasonal variations in discharges prove the impacts of climate change. Such climate change increases the air temperature, thus affecting snow buildup and melting and thereby resulting in decreased spring snowmelt discharges and increased winter discharges.
Depending on the timing of the floods, location and catchment features, and the applied climate setting, projected changes in the floods from 2070 to 2099 differed significantly. Winter and autumn floods caused by precipitation raised particularly in lakes and outflow rivers, while floods caused by spring snowmelt reduced or remained the same.
Considerable variations between the results produced from diverse climate settings denote uncertainties regarding the effects of climate change and these uncertainties further increase because of the uncertainties present in techniques and models.
Various techniques were applied to transfer the climate variation signal from the climate model to the hydrological model. The effects of climate scenarios, applied techniques and catchment features on the results were also evaluated.