Question

9- Stream flow record lengths are generally short. To estimate exceedance probabilities, it is a common practice to fit frequency functions to annual flood data.Flood quantiles are computed from the fits of frequencies to different gauging stations in a homogeneous region on which regional quantile regressions are done. Obtain an empirical cumulative frequency function for the maximum annual flood date given below (Q in cfs) using (i) Weibull plotting position formula. (ii) Fit a log-Pearson type III distribution to this data. Show your calculations clearly (Seehttps://streamflow.engr.oregonstate.cdu/analysis/floodfreg/index.htm and https://streamflow.engr.oregonstate.edu/analysis/floodfreq/meandaily_example.htandmas a guide for your calculations) (iii) Calculate flood quantiles with 25 yr return period and 125 yr. return period from the two methods, and briefly discuss your reasons for differences/similarities in the computed values.

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