Latkovska, I., Apsīte, E., Elferts, D., Kurpniece, L.
Forecasted changes in the climate and the river runoff
regime in Latvian river basins
The hydrological model HBV (Hydrologiska Byråns
Vattenbalansavdelning model) has been applied to six river basins in Latvia to
assess climate change and its impacts on the river runoff regime at the end of
the 21st century. Climate change has been predicted by applying the regional
climate model RCAO with the driving boundary conditions from the global general
circulation model HadAM3H applied for the IPCC scenarios A2 and B2 and the
following time periods: 1961–1990 (control) and 2071–2100 (scenario). Changes
have been found under both scenarios. Major changes in the future hydro-climate
data were forecasted according to the A2 scenario, where the trends of increase
are identified for the annual mean air temperature (by 4°C), the precipitation
(by 12%) and the evapotranspiration (by 21%), while the river runoff will
decrease by 15% at the same time. The changes in the length of the growing
season and heavy rainfall have been predicted. Both scenarios forecast changes
in the seasonal runoff regime where the major part of the runoff will be
generated in winter, followed by spring, autumn and summer. The maximum river
discharge will occur in winter instead of spring.