Flood Control Plan of Urban Medium and Small Rivers with Strage Facilities

Abstract

We have examined the stochastic analysis of the precipitation in Tokyo for the flood control plan, considering the two different heavy rains.The results are as fol lows.(1) Probability distribution: the stochastic analysis of precipitation in Tokyo supports ‘the square root exponen-tial-type distribution’ more than the Gumbel's and the logarithm normal one.(2) Separation of rainfall types;the Cleveland-type rainfall intensity formula agrees with the local heavy rains data better than the typhoon's and the total ones.(3) Two hyetograph model;‘the equi-risk line’ agrees with the typhoon-type rainfalls very well, also the traditional ‘central peak shaped’ rain-fall model does with the local heavy rains as the same.(4) Applications: the equi-risk line model has been applied to convert the amount of infiltration into the equivalent storage one.