Morphodynamics and sedimentation in the semienclosed macrotidal flats: role of rainfall-induced runoff discharge and human disturbance - datasets and supplementary materials

Published: 16 March 2021| Version 1 | DOI: 10.17632/f66r4hvrdg.1
Contributors:
Dohyeong Kim,
Joohee Jo,
Kyungsik Choi

Description

This directory contains the following supplementary tables and drone-derived datasets collected between 2017 and 2020 in the Shinsi tidal flats, west coast of Korea. The dataset indicates that the Shinsi tidal flats display non-seasonal morphologic changes and sedimentation pattern during the study period despite the strong influence of monsoonal weather. Georeferenced orthophotomosacis were collected seasonally and processed to produce digital elevation models (DEMs) using Pix4D. Sediment volume changes between the specific periods were calculated by substracting the two DEMs corresponding the periods (e.g., DoD_2019_autumn_lower.tif is the difference between DEM_2019_October_lower.tif and DEM_2019_August_lower.tif, DoD_2020_spring_lower is the difference between DEM_2020_February_lower.tif and DEM_2019_October_lower.tif). Files in Figure 7, Figure 8, Figure 9, Figure 13 folders are part of entire tidal flats (Figure 4). Due to large file size for original tiff files (typically greater than 1 GB), we uploaded tiff files with reduced resolution (10 cm). The resolution of the original tiff files are less than 2 cm. Despite the reduced file resolution, there is no significant increase in root mean squre errors for DoD analysis. The original tiff files are available on request. % in Parentheses in Table 1 and supplementary tables (ST1, ST2, ST3) indicate the percentage of the total area that combines erosion area, deposition area, and undetectable area. Undetectable area refers to the area at which the difference between two DEMs is smaller than the calculated error. SUPPLEMENTARY TABLES - Table 1 & Supplementary tables.xlsx DRONE_DERIVED DATASETS - Figure 4 - entire tidal flats - DEM_October 2017_entire tidal flat.tif, DEM_October 2020_entire tidal flat.tif, DoD_between_2017_2020_entire tidal flats.tif, Orthophotomosaic_October_2017_entire tidal flats.tif, Orthophotomosaic_October_2020_entire tidal flats.tif; drone-derived digital elevation models, DEM of difference (DoD) and orthophotomosaics of entire tidal flats (~173,732 square meters) in the south of Shinsi tidal flats; georeferenced - Figure 7 - upper intertidal zone - a time-series of drone-derived digital elevation models, DEM of difference (DoD) and orthophotomosaics of upper intertidal zone area (60 x 45 m) in the south of Shinsi tidal flats; georeferenced - Figure 8 - tidal channel - a time-series of orthophotomosaics of middle intertidal zone area (115 x 140 m) in the south of Shinsi tidal flats; georeferenced - Figure 9 - middle intertidal zone - a time-series of drone-derived digital elevation models and DEM of difference (DoD) of middle intertidal zone area (190 x 140 m) in the south of Shinsi tidal flats; georeferenced - Figure 13 - lower intertidal zone - a time-series of drone-derived digital elevation models and DEM of difference (DoD) of lower intertidal zone area (60 x 45 m) in the south of Shinsi tidal flats; georeferenced

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Drone-derived datasets were obtained by repeated UAV surveys on the macrotidal Shinsi tidal flats on the west coast of Korea. Drone-captured images were all georeferenced by implementing the RTK-GPS survey. The images were rectified and processed to produce digital elevation models (DEMs) using Pix4D (version 4.0.25). To quantify morphological changes and sedimentation, DEMs were obtained repeatedly on a seasonal basis over the four years. By subtracting the DEMs between the two periods, sediment volume change such as erosion and deposition can be quantified. Also, morphological changes such as landward migration of shelly ridges and the growth of the tidal channels can be detected by comparing the time-series of the DEMs.