Rating curve estimation using remote sensing hydraulic data and isovel
contours at Karun River
Abstract
Determining discharge and stage-discharge curves in rivers or basins
without Hydrometric gauges is critical challenge in hydrologic studies
and river hydraulics. Researchers and designers have always been trying
to access simpler and cheaper methods to estimate discharge and rating
curves. This research aims to facilitate the determination of the
discharge and stage-discharge relationship by applying remote sensing
techniques as well as the concept of isovel contours. For this purpose,
the geometry of the river cross-section is determined using remotely
sensed data from the images of the Sentinel2 satellite, and then
discharge passed through the cross-section is estimated by the single
point velocity measurement method (SPM). The observed data were
collected from the Mollasani station in Karun River, Iran, to confirm
this method. The obtained discharges and stage-discharge relationship
curves are used to evaluate the accuracy of the proposed methodology.
Statistical analyses showed that the mean value of the percentage
error(%E) and Mean Absolute Percentage Error (MAPE) calculated based on
the difference between the estimated and observed discharges are limited
to 6.3% and %8.36, respectively. Also, the stage-discharge curves in
these studies were estimated with a maximum MAPE of 9.5%.