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Beach ridges detection on the Dolgaya Spit based on remote sensing data

The study of the ridge systems’ morphology on accumulative coastal land forms makes it possible to reconstruct their development. The spatial orientation and height of the beach ridges provide information on the predominance of certain processes at different time intervals. The Dolgaya Spit, which is one of the largest accumulative forms of the Sea of Azov, is characterized by the presence of well-distinguishable generation of sand-shell ridges. The article discusses the possibility of using various remote sensing data to identify beach ridges on the Dolgaya Spit.

In this study the data of ground measurements of elevation points performed during the expedition in the summer of 2020 are used. The statistical characteristics of the ridges on the investigated area of the spit are given. The analysis of the possibility of identifying beach ridges on the spit based on high-resolution satellite optical images has been done. It was concluded that it is impossible to unambiguously determine the ridges, since the optical characteristics of the soil and vegetation cover on the Dolgaya Spit do not allow separation of the microrelief forms.

The second source of remote sensing data was aerial photography of a part of the Dolgaya Spit using the unmanned aerial vehicle “Phantom 3 PRO”, followed by photogrammetric processing of the obtained digital images. The stages of processing the survey results for the construction of a digital elevation model and an orthomosaic of the investigated area are considered. The quality of the obtained digital elevation model was assessed by comparison with ground measurements of elevation points. The article discusses the source of errors in the obtained digital elevation model. It is noted that the construction of a digital elevation model with acceptable quality is possible only for the spit’s regions with sparse vegetation cover.