UAV-BASED 1/500 TOPOGRAPHIC MAPPING FOR ESTIMATING LIMESTONE VOLUME AT TRAI SON QUARRY, VIETNAM

Abstract

Calculating the amount of limestone extracted is important for managing resources and protecting the environment at quarries. However, traditional methods are expensive, take a lot of time, and are not very accurate, especially in the areas like Trai Son Quarry. This study solves these problems by using UAV (Unmanned Aerial Vehicle) technology to generate a highly accurate 1/500-scale topographic map with 1-meter contour intervals and boundaries delineated at a 1/1000 scale for precise volume estimation. The research used drone-based photogrammetry to capture high-resolution images of Trai Son Quarry, with ground control points measured by GNSS (Global Navigation Satellite System) to ensure accuracy. The obtained data was used to generate a DEM (Digital Elevation Model) and orthophoto maps. The results indicated that the drone-generated map was extremely accurate, with m_xy (horizontal accuracy) of less than 0.082 m and an m_h (vertical accuracy) of less than 0.1 m. The study determined that the remaining limestone volume above +5 m elevation is 519,324 m³, while the excavated volume below +5 m is 84,078 m³. Using drones also reduced fieldwork time by 60% while keeping costs low, providing reliable data for quarry operations and legal requirements. The use of UAV technology at Trai Son Quarry proves that it is an effective and accurate way to map and measure limestone extraction, even in difficult terrains. Future research will expand UAV applications to other quarries in Vietnam, with regular map updates and GIS (Geographic Information System) integration to improve resource management and environmental planning.