A Field Imagery and Measurement Dataset for Grain-size Analysis of Riverbed Gravels in the Mid-Geum River

This study constructed and released a field imagery and measurement dataset for analyzing the grain size of riverbed gravels in selected point-bar areas of the mid-reach of the Geum River, Korea. The survey methodology included drone imaging, ground control point surveying, and image preprocessing. The dataset comprises high-resolution 1×1 m orthomosaic images of quadrats and corresponding field-measured grain-size data for 103 gravel samples. These data can serve as training and validation datasets for automating gravel grain-size analysis and enable quantitative comparisons of sedimentary environmental changes through periodic monitoring. However, the dataset was constructed from a single quadrat and therefore does not fully capture the spatial variability of the entire point bar. Expanding the dataset by installing additional quadrats in future studies would enhance its representativeness and enable broader applications in river management, restoration planning, and habitat assessment.