Title: Bivariate flood frequency analysis - a case study of Hirakud reservoir inflow
Authors: Raj Beer Padhee; Anil Kumar Kar; Pradip Kumar Das
Addresses: Civil Engineering Department, Veer Surendra Sai University of Technology, Burla, 768018, Odisha, India ' Civil Engineering Department, Veer Surendra Sai University of Technology, Burla, 768018, Odisha, India ' National Institute of Technology, Rourkela, Odisha, 769008, India
Abstract: Reservoir inflow as form of flood hydrograph has significant role in reservoir operation. The inflow (discharge), volume and duration are common variables, and the fourth variable of flood hydrograph, i.e., the time to peak has been introduced into the analysis. New combinations are generated for peak (Qp) and time to peak (Tp), volume-time to peak and duration-time to peak, to determine the bivariate probability distributions. The correlation of Qp-Tp was approximately equal to zero, behaving independently. The EV1 distribution showing best fit marginals for peak, volume and duration with corresponding AIC values as -45.57, -47.29, -51.20 and for Tp, gamma remains the best fit with -45.66. These best fit marginal for different variables were applied to the family of Archimedean copula along with dependency factor (θ), determining the bivariate probability distributions for best fit copula for different bivariate pairs and its conditional probability were determined.
Keywords: time to peak; time to peak-volume; time to peak-duration; copula.
DOI: 10.1504/IJHST.2022.126433
International Journal of Hydrology Science and Technology, 2022 Vol.14 No.4, pp.390 - 405
Received: 04 Aug 2020
Accepted: 28 Dec 2020
Published online: 26 Oct 2022 *