FREQUENCY ANALYSES OF NON-STATIONARY MONTHLY, SEASONAL AND ANNUAL RAINFALLS IN THE HIDAKA RIVER BASIN

Abstract

With the recent occurrence of frequent droughts or floods exceeding conventional predictions, an existing assumption of stationary rainfall is no longer applicable to frequency analyses in many cases.
On such a background, this paper reports the results of frequency analyses of non-stationary monthly, seasonal and annual rainfalls with a non-exceedance probability of the design level, a key index in discussing drought problems.