Simulating pre-monsoon and post-monsoon flows at Farakka barrage, India

Spatial and temporal variation in flow rate for any particular area are prevalent due to various meteorological and other factors existing in nature. However, significant variations in these factors cause extreme events (e.g., floods and droughts). Farakka barrage is located on the Ganges River, and the discharge data are classified for several years now. In this study, 25 years mean monthly observed outflow discharge of Farakka barrage, available from 1949 to 1973, to simulate the monthly observed outflow discharge and identify a suitable model for synthetic flow generation. To achieve this, the performance evaluation of Copula models and ARMA models has been evaluated. Different Copulas (i.e., Frank, Clayton, Gumbel-Hougaard, Ali-Mikhail-Haq) are used. The study indicates that the performance of Copula is better than ARMA for any set of series. This finding may be useful for other site studies where a similar situation prevails in terms of flow data availability.