Application of UAV in Rip Current Investigations

Cases of people dying from being swept away on the beach have been widely published on Bali news; this is because not many people know the dangers of rip currents on the beach. Lack of public knowledge about rip currents is caused by a lack of socialization and warning signs of rip currents on the beach. Rip currents are back currents formed by currents coming perpendicular to the shoreline and meeting the curved shoreline. This current can drag someone who is swimming out to sea. In this study, the existence of rip currents was investigated using aerial photographs or UAVs. The observation location was taken in an area that is often used by the Balinese Hindu community to carry out the Ngaben ceremony process. The UAV device was prepared to observe the rip current and measure its speed. Dye Tracer Test was also conducted to observe the movement of rip currents visually. Rip currents are characterized by calmness between rows of breaking waves. The average rip current speed is 0,29 m/s can also be determined by observing the UAV. The speed of this current is influenced by wave energy that propagates to the beach. The difference in bathymetry causes variations in wave height along the beach, and the rip current causes this. The results of this study can be used as an early warning system for people who carry out activities on the beach.