SRTM Data Application for Extrapolation of Rating Curves (On the Example of the Iya River at the Tulun Gauge)

Abstract

The manuscript discusses the method developed by the authors for restoring the cross-sectional area curve and extrapolate rating curves for the Iya River at the Tulun gauge, using the Shuttle Radar Topography Mission (SRTM) data. As part of the work, the systematic correction for the study area was determined to recalculate altitudes from a digital terranean model according to SRTM topographic data to the Baltic Height System. The river width data from SRTM-based information after systematic correction are in good agreement with the width from large-scale satellite images as well as with the field width measurements at appropriate levels. The paper presents the results of the extrapolation of the rating curve, using the Chezy equation approach, the Stevens-Velikanov technique and the stage-area and stage-velocity method, using the area curve and the average depth curve obtained on SRTM materials. For each research method used in the study, by comparing with the reference of rating curve, the values of the average probable deviation were calculated. As part of the study the extrapolated rating curve is presented as an analytical equation, and the approximation error is determined.