1948 Landforms and Their Transformation in the Central and Southern Parts of Okinawa Island


Abstract: This study enhances the grid elevation generation method established by Watanabe et al. (2014) using the U.S. military’s 1/4800 topographic maps. By modifying this method, the research swiftly generated grid elevation data for the entire southern region of Okinawa Island. By analyzing the differences between this grid elevation and the actual terrain, it was observed that alterations in topography from cut-and-fill activities, specifically from Nakagusuku Town to Okinawa City, extended across these entire areas. It was also discovered that distribution patterns varied due to geological and topographical differences. Additionally, digital topographic maps derived from this grid elevation and 3D terrain views unveiled the distinct topography formed by the subtropical climate and the geological formations of the Shimajiri Group and Ryukyu Limestone. (ChatGPT)

Abstract: In this study, we improved the method of generating grid elevations for 1/4800 topographic maps produced by the U.S. Army, established by Watanabe et al. (2014), and generated grid elevations for the entire south-central area of Okinawa Island in a short time. The grid elevations were obtained from the difference between the grid elevations and the local topographic features. The cut-and-fill data obtained from the difference between the grid elevations and the field profiles indicate that topographic changes have occurred throughout these areas, and that the distribution of the land varies depending on the geology and topography. Digital topographic maps and 3D topographic views created from the grid elevations reveal a unique topography composed of subtropical climate, the Shimajiri Group, and Ryukyu limestone. (DeepL)