A Geological Environment Characteristics Dataset of Tidal Flat Surface Sediments: A 2021 Pilot Study of the Gomso Bay Tidal Flat Area to Use of Sediment Type Data

Abstract

The Gomso Bay tidal flat is located between Buan-gun and Gochang-gun in Jeollabuk-do, Korea; it is a semi-closed bay in an area where tides prevail over waves. Tidal flats are mainly found south of Gochang-gun, and the main stream located north of the tidal flats is about 15 m deep and 900 m wide at low tide. Limited direct sampling is necessary for analyzing the geological environment of intertidal tidal flats, depending on the expected ebb-tide time and the number of survey items allowed for tidal flat access. This study assessed field measurement and laboratory analysis items for obtaining and establishing geological environment data to use of sediment type data in a pilot research area in the Gomso Bay tidal flat. Thirty sites were examined on June 22 and 24, 2021 (survey time about 3.5 hours for the 2 days). The field measurements were the sample date (year/month/day/hour/minute), ellipsoid height using a real-time kinematics global positioning system (RTK GPS) (m), shear strength (kg/cm<sup>2</sup>), and Munsell color. Samples for particle size (phi, Φ), specific density, porosity (%), moisture content (%), total organic carbon (%), total carbon (%) and total nitrogen (%) were placed in zipper bags and polypropylene (PP) bottles. The sedimentary phases were classified following Folk and Ward (1957), the organic matter was characterized based on particle size analysis and each experimental result was verified. In the future, a geological environment characteristics dataset based on this pilot study will be used as basic data to assess changes in the tidal flat topography and sedimentation environment. It should be useful data for research, tidal flat environment conservation management and free open data for users of related researchers.