Author(s): V. G. Shashank; V. Sriram; Holger Schuttrumpf; S. A. Sannasiraj

Linked Author(s): Sannasi Annamalaisamy Sannasiraj

Keywords: Storm surge; ADCIRC; GAHM; Bottom friction coefficient; Wind drag coefficient

Abstract: This study focuses on the impact of the effective combination of different bottom friction coefficient and wind drag coefficient formulations on the storm surge for the tropical cyclone Yaas in the Bay of Bengal using a hydrodynamic finite element-based 2D (ADvanced CIRCulation) ADCIRC model. A methodology adopted in which the parameters of linear, quadratic (spatially constant and spatially varying), and nonlinear hybrid bottom friction coefficient formulations are systematically increased and decreased by 50% in combination with the Garratt, Powell, Wu, and Zijlema wind drag coefficient formulations to quantify their impacts on the hindcast. Simulated residual water levels are compared with observed data collected from the Dhamra in situ tide gauge station. It is evident that lower bottom friction and a higher wind drag coefficient cause an increase in storm surge water levels. The linear bottom friction formulation performs poorly, with Root Mean Squared Error (RMSE) ranging from 0.384 to 0.775 m, whereas the nonlinear hybrid bottom friction performs better, with RMSE ranging from 0.235 to 0.384, followed by the quadratic bottom friction coefficient ranging from 0.181 to 0.584 m. Wu's wind drag formulation overpredicts surge value, whereas the rest of the wind drag formulations underpredict.

DOI: https://doi.org/10.1007/978-981-97-6009-1_51

Year: 2022