HYPSO: a new multiresolution global raster digital elevation model for small-scale terrain mapping

During the last decade a significant progress in methods and techniques of elevation data acquisition has been achieved. With lidar-derived digital elevation models it is now possible to investigate landforms with precision and detail which was never possible before. The resolution of global and continental elevation models is approaching first meters, which enables detailed geomorphometric analysis and mapping in wide spatial extents. At the same time, Earth scientists are interested not only in learning the properties of small landforms, but also in investigating the large regional terrain features, as well as hierarchical properties of terrain structure. For this, small details must be omitted from digital elevation model, and the analyzed dataset is expected to have coarser resolution. Currently available coarse-resolution global digital elevation models such as GMTED2010, GEBCO_2019 and ETOPO1 are characterized by spatial resolution ranging from 7.5” to 1’, which is approximately equal to cell size of 250-2000 m on the equator. Such resolution fits well into the small-scale mapping and analysis context. However, these models have excessive level of detail in relation to their resolution, which is a consequence of the method of their derivation — mainly aggregation and resampling of more detailed data. As a result, terrain maps created using these models, are characterized by lack of generalization, which prevents realistic portray of large terrain forms. To solve the problem, the new high-quality mutiresolution digital elevation model HYPSO has been developed. HYPSO is derived based on GEBCO_2019 model (15” resolution) using the structural generalization, during which the less detailed terrain surface is reconstructed from characteristic stream and watershed lines. HYPSO includes eight levels of detail (LoDs) with resolutions 30”, 1’, 2’, 4’, 8’, 16’, 32’ and 64’ which are suitable for mapping any region on the Earth including the seabed at scales 1:1 000 000 and smaller. The sequence of LoDs is characterized by sequential decrease in detail, which enables production of multiscale maps. Additionally, HYPSO is spatially conflated with river/lake centerlines in popular Natural Earth cartographic database and can be used as a background terrain layer in production of general geographic (base) maps. While the primary purpose of HYPSO is hypsometric mapping, it is also suitable as a data source for performing the geomorphometric analysis aimed at investigating the properties of large terrain landforms, which is demonstrated on several examples.

The study was supported by the Russian Science Foundation grant No. 19-77-10071