Testing a Hydrological Model to Evaluate Climate Change Impact onRiver Runoff

For two hydrological models, the ECOMAG and SWAP, the hypothesis is checked that a model which has successfully passed the test based on observational data is more efficient for assessing future hydrological consequences of climate change than the models which did not pass the test. The efficiency is evaluated using two criteria: the robustness of a model and the uncertainty of simulation results. Three versions of each model constructed for the basins of the Lena and Mackenzie rivers are examined: the model whose parameters are set a priori (without calibration), the model which was calibrated against runoff hydrographs at the outlet, and the model which was calibrated against runoff hydrographs at several gaging stations of the river network. The estimates of possible changes in the river runoff by the end of the 21st century are obtained using data of global climate models. It is shown that the hydrological model which successfully passed the proposed testing procedure is more effective for assessing climate change impact on the river runoff.