A Study of Applicability of ERA5 dataset for Nearshore Wave Simulation

The purpose of this study is to investigate the applicability of ERA5 reanalysis data to force nearshore wave model(SWAN) in Korea. A nearshore wave model was set up to simulate wave transformations in December 2016, in Ilsan beach located in Ilsan-dong, Ulsan Metropolitan City. The numerical results by ERA5 inputs were compared with the results by ERA-Interim inputs. The ERA5-based simulation results show better agreement with field observations than the ERA-Interim ones do. In addition, the wave model results have been improved by applying whitecapping empirical formulas of Rogers et al.(2012) among physical parameters.33Nkciothe

Sensitivity Analysis in the Prediction of Coastal Erosion due to Storm Events: case study-Ilsan beach

In coastal morphological modelling, there are a number of input factors: wave height, water depth, sand particle size, bed friction coefficients, coastal structures and so forth. Measurements or estimates of these input data may include uncertainties due to errors by the measurement or hind-casting methods. Therefore, it is necessary to consider the uncertainty of each input data and the range of the uncertainty during the evaluation of numerical results. In this study, three uncertainty factors are considered with regard to the prediction of coastal erosion in Ilsan beach located in Ilsan-dong, Ulsan metropolitan city. Those are wave diffraction effect of XBeach model, wave input scenario and the specification of the coastal structure. For this purpose, the values of mean wave direction, significant wave height and the height of the submerged breakwater were adjusted respectively and the followed numerical results of morphological changes are analyzed. There were erosion dominant patterns as the wave direction is perpendicular to Ilsan beach, the higher significant wave height, and the lower height of the submerged breakwater. Furthermore, the rate of uncertainty impacts among mean wave direction, significant wave height and the height of the submerged breakwater are compared. In the study area, the uncertainty influence by the wave input scenario was the largest, followed by the height of the submerged breakwater and the mean wave direction.22Nkc