ANALYZING TAIL DEPENDENCY OF RIVER DISCHARGE BETWEEN TWO RIVERS OF ALL CLASS-A RIVERS IN JAPAN USING BIVARIATE EXTREME VALUE DISTRIBUTION AND d4PDF

Abstract

 We applied the bivariate extreme value theory to extreme river discharge data calculated from d4PDF historical climate experiment in 5, 886 pairs of class-A rivers in Japan and analyzed their tail dependence and joint flood probability. The results found various pairs having joint floods at return period less than 500 years over Japan, especially in the Chugoku region where more than three rivers could flood as well. Occurrence months of joint floods in d4PDF data depicted their seasonal patterns such as Baiu front and typhoons. Interestingly, distant pairs such as Koyoshi and Shimanto Rivers have certain tail dependence, which is found in typhoon seasons in d4PDF.