On the methods for the construction of seabed digital elevation models (using the example of the White Sea)

摘要

A digital elevation model (DEM) of the White Sea has been constructed based on navigational maps on different scales. The maps have been scanned, and their raster images have been processed. The isobaths have been vectorized, and attribute tables have been created. The vector layers have been transformed from map projections to geographical coordinates. The sheets have been edited and stapled. The geometry and attributes have been corrected. When constructing a DEM, it is important to choose an algorithm that will make it possible to maintain the bed forms expressed in the raw isobaths with maximum detail in the model. An original algorithm developed and implemented by the authors is used. It is based on the fast computation of the distances to the two nearest isobaths at different levels. Its main feature is the interpretation of the contour lines as linear vector objects. The comparison of the depths based on the constructed seabed DEM with depths measured during echo sounding in natural conditions shows their good agreement. Currently, not only the constructed seabed digital elevation model but also methodical and methodological bases of numerical simulations, including the new classification approaches to the terrain description, are relevant.