Geoinformation Maps of the Northeast Asia Relief as a Basis For Studying the River Basins Morphology

Abstract

Aim. Creation of the first geoinformation maps of mountainous relief of Northeast Asia and obtaining the morphological characteristics of catchments on this basis, both available in information sources and new ones, with an assessment of the accuracy and level of correlations between them. Materials and methods. On the basis of comparative analysis of the methods of quantitative morphometry of the Northeast Asia relief (aerial photographs, maps, GIS technologies) the prospects for expanding the information base with the help of geoinformation maps has been established. The use of digital terrain models is most important for poorly studied basins of small rivers, data on which are not available in reference sources. The chosen universal program ArcGIS, version 10.4, makes it possible to obtain entirely new parameters of the catchment areas of mountain rivers. In this regard, the digital map with elevation marks of the earth's surface relief (SRTM) served as a source material for calculating various morphometric characteristics of catchments (for example, areas and average heights of catchments, length of streams, etc.). Results and discussion. Statistical analysis of catchment areas, based on geoinformation maps (ArcGIS program, version 10.4) and raster analogs, indicates their insignificant difference (– 3.9 to +3.0 %). The use of digital elevation models is shown to be promising for obtaining completely new characteristics of river basins that are absent in known information sources (for example, shapes, perimeters, slopes of average heights, etc.). In addition, on the basis of statistical analysis, an assessment of the parameters of various catchments and their parts (upstream, downstream) is given, for example, the heterogeneity of the surface of river valleys and watersheds. In addition, a close, or, in some cases, functional relationship has been established between some characteristics of the catchments (for example, slopes – average heights). Conclusions. First digital models of mountainous relief in Northeast Asia (ArcGIS, version 10.4), made it possible to calculate the main morphometric parameters of river catchments with sufficient accuracy. The use of digital maps with the heights of the earth's surface, in particular, SRTM, made it possible to obtain entirely new, comparing to the existing level of knowledge, parameters of watercourse basins necessary for science and practice.