Coastal inundation modeling and mapping for North Jakarta coast during a supermoon period

Coastal areas are very vulnerable to disasters. One of the disasters that needs serious attention in coastal areas, including the coast of Jakarta, is coastal inundation. However, there is no integrated coastal inundation prediction system implemented in this area. This study aimed to build a model of coastal inundation by combining various factors, namely hydrodynamic model, wave model, and river model. The model used in this research is the integration of the Delft3D model, the WaveWatch III-SWAN model, and the SOBEK model. The results show that the simulation of the water level was in accordance with the observed data, from 30 November to 8 December 2017 during the supermoon period with a correlation accuracy of 0.9 and RMSE of 5.9 cm. However, the results of the simulation and astronomical tide prediction have a correlation of 0.81 and an RMSE is 13.6 cm. Therefore, it can be seen that the model is better than the astronomical tide prediction. The hydrodynamic model shows that Jakarta Bay has a water level range of 0.66 to 0.68 m during the supermoon period. The mapping of flood inundation areas show that the water level in the Tanjung Priok and Marunda in North Jakarta has a maximum inundation level of 50 to 100 cm with an inundation area of 272.17312 and 456.03653 m². Meanwhile, our analysis for the Ancol and Kalibaru shows an inundation level of 0 to 30 cm with an inundation area of 388.04358 and 169.17656 m². Our model provides better accuracy because it takes into account several important variables for modeling coastal inundation. Our early warning system proved to be accurate in providing coastal inundation prediction information for the North Jakarta area.