Low-cost investigation of wave dynamics across low energy reef environments
Johan Risandi1, Tubagus Solihuddin1, Tery L Kepel1, August Daulat1, Aida Heriati1, Eva Mustikasari1, Rahman Hidayat2-3

1. Marine Research Center, Jakarta Indonesia
2. Assistant Deputy for Basic, Urban, and Water Resources Infrastructure, Deputy for Infrastructure and Transportation Coordination, Coordinating Ministry for Maritime Affairs and Investment-

3. On leave from : Research Center of Hydrodynamics Technology, National Research and Innovation Agency

Abstract

The interaction between offshore waves and complex reef bottom profiles determines the hydrodynamic processes within the reef beaches, for instance, Sea-Swell (SS) wave dissipation, Infragravity (IG) wave generation as well as wave-induced currents and setups. These hydrodynamics phenomena are important to several ecological processes and control the associated shoreline erosion and flooding. Hence, a good understanding of the dynamics is needed that wave observations in shallow water are challenging and expensive otherwise. Here we present a short term (12 hours) investigation of non-directional spectral waves using a series of HOBO pressure sensors. Six pressure sensors were deployed at 3 locations along the fringing reefs of Tunda Island, Banten Province - Indonesia. The wave spectra were estimated from the surface water fluctuations using linear wave theory for each hourly burst data. During observation, the Tunda waters were calm with significant wave heights were less than 10 cm with peak wave periods of ~12 s at all sites. Despite the short period measurement due to memory issue, the result demonstrated the ability of HOBO pressure sensors to measure nondirectional wave spectra at shallow water.

Keywords: Wave dynamics, HOBO pressure sensors, reef beach, Tunda Island

Topic: Oceanography (International)