FLOOD FREQUENCY ANALYSIS OF RIVER KOSI, UTTARAKHAND, INDIA USING STATISTICAL APPROACH

Saurabh Sah, Jyothi Prasad

Abstract: In the present study, flood frequency analysis has been applied for river Kosi in Uttarakhand. The river Kosi is an important tributary of Ganga river system, which arising from Koshimool near Kausani, Almora district flows on the western side of the study area and to meet at Ramganga River. The annual flood series analysis has been carried out to estimate the flood quantiles at different return period at Kosi barrage site of river Kosi. The statistical approach provided a significant advantage of estimation of flood at any sites in the homogenous region with very less or no data. In the at –site analysis of annual flood series the Normal, Log normal, Pearson type III, Log Pearson type III, Gumbel and Log Gumbel distribution were applied using method of moments . From the analysis of different goodness of fit tests, it has been found that the Log Gumbel distribution with method of moment as parameters estimation found to be the best-fit distribution for Kosi River and other sites in the region. It is recommended that the regional parameters for Kosi Basin may be used only for primary estimation of flood and should be reviewed when more regional data available

Keywords: Flood Frequency Analysis, River Kosi, Annual Peak Flood discharge, Return Period, Goodness of fit Test.

DOI: https://doi.org/10.15623/ijret.2015.0408053