1-Flood Estimation in India using regional frequency analysis

Abstract

The use of regional flood frequency approach provides one of the most effective ways for the estimation of design floods at ungauged sites. Many distributions such as Gumbel EV-I, Log normal, Log Pearson type-3 etc, are some of the most frequently used distributions for flood frequency analysis. Recently, a very versatile five parameters distribution known as 'Wakeby Distribution has been introduced for modelling of flood flows, which overcomes many deficiencies associated with the traditional distributions. In this paper, some of the flood frequency studies conducted for different regions in India are briefly reviewed. Procedure and results of regional flood frequency analysis using Wakeby distribution for some typical regions of India have been described and discussed. Regression relationships in the form of Q= A(CA) B have been developed between the James Stein corrected mean flood, and catchment area. Though the computations for Wakeby distribution are quite involved, with the use of computer programmes quite encouraging resultE have been obtained.