Abstract: The probability change of extreme hydrological events under climate change is analyzed by constructing multi-variable model between climate factors and extreme events. Taiyuan meteorological station in the Yellow River basin and Lutaizi hydrological station in the Huaihe River basin are selected as study area. The results of Taiyuan station show that Gumbel Copula can better simulate the dependence structure of antecedent cumulated precipitation and monthly PDSI series. As the precipitation amount increases, the probability of extreme drought decreases while the probability of severe, moderate and slight drought firstly increases and then decreases. The results of Lutaizi station show that Clayton Copula can better simulate the dependence structure of precipitation and peak of flood. When the precipitation is over or equal to a certain value, the conditional probability of the extreme flood events that peak flow is over or equal to x gradually decreases as the annual maximum peak flow increases. Under the same conditional probability, the peak flow is more likely to get large values when the cumulative precipitation is large.

Key words: climate chang, extreme hydrological event, Copula function