Application of low-altitude remote sensing technology in coastal geological environment monitoring: a case study of Yazhou bay in Hainan Island

As an important southern trading port in China, Yazhou Bay on Hainan Island has developed rapidly in marine technology and industry in recent years. Due to the lack of effective monitoring means and long-term monitoring data, the status and research of the coastal geological environment in this region are relatively backward, which restricts the sustainable development of its marine economy. In this paper, based on the geological environment elements extracted from the low altitude aerial remote sensing images of multiple unmanned aerial vehicles (UAV), the Digital Orthophoto Image and surface elevation model of the coastal zone are constructed, the dynamic analysis of coastal erosion and deposition is carried out, and its stability is evaluated. The research shows that most of the coastal zone of Yazhou Bay is in an erosive state before the implementation of the artificial sand filling project. After one year of sand filling and repair, affected by the Breakwater Project, the erosion and deposition in the northern section continued to erode, while the erosion and deposition in the central section tended to be in dynamic balance, and the adjacent area of Nanshan port in the South showed significant deposition. Scientific and reasonable combination of various restoration methods can improve the stability and functionality of sandy shoreline.