Estimating stream flow has a substantial financial influence, because this can be of assistance in water resources management and provides safety from scarcity of water and conceivable flood destruction. Four common statistical methods, namely, Normal, Gumbel max, Log-Pearson III (LP III), and Gen. extreme value method are employed for 10, 20, 30, 35, 40, 50, 60, 70, 75, 100, 150 years to forecast stream flow. Monthly flow data from four stations on Mahanadi River, in Eastern Central India, namely, Rampur, Sundargarh, Jondhra, Basantpur are used in the study. Result shows that Gumbel max gives better value of flow discharge than the Normal, LP III, and Gen. extreme value methods for all four gauge stations. Estimated flood values for Rampur, Sundargarh, Jondhra, Basantpur stations are 372.361 m3/sec, 530.415 m3/sec, 2,133.888 m3/sec, 3,836.22 m3/sec, respectively, considering Gumbel max. Goodness of fit test for four statistical distribution techniques applied in the present study are also evaluated using Kolmogorov–Smirov, Anderson–Darling, Chi-squared tests at critical value 0.05 for the four proposed gauge stations. Goodness of fit test results show that Gen. extreme value gives best results at Rampur, Sundergarh, Jondhra gauge stations followed by LP III whereas LP III best fits for Basantpur followed by Gen. extreme value.
Four statistical methods like Normal Distribution, Gumble Distribution, Log Pearson Type III and Extreme Distribution method are employed to forecast stream flow up to 150 years.
Goodness fit test for above four statistical method also studied to find out the rank of data series at 5% significance level.
Confidence band in the sense of maximum flow discharge is evaluated up to 95% of confidence limit.
Sensitivity of all physical parameter also discussed on the four statistical methods.
Hydrological data are discuss through various statistical indices.