Аннотация:An application of regional distributed hydrological model ECOMAG to study of climate change impact on river runoff in the NOPEX area is considered using coupled historical and modelling approaches. At first the analysis of the observed hydrological and meteorological data for 15 years has allowed both to distinguish the "cold" and "warm" subsets during given period, and to develop "natural climate changes" (NCC) scenario very similar to that, simulated by GCMs for warming in the next century. Then validated ECOMAG model has been applied to the runoff simulations for the "cold" series under NCC scenario. These results have been compared to the observed data on discharge for the "warm" series. The possibility to compare the changes in simulated runoff to the observed ones during the non-stationary climatic period is very useful validation of hydrological models to study climate change impact on water resources that might reduce many uncertainties connected with adequacy of the hydrological models.