Aplication of cross-sectional velocity distribution model and stage-discharge rating curve to estimate water discharge in the Lo river basin at Vinh Tuy station, Ha Giang province

Abstract

This paper presents computed results of daily water discharge in the Lo river basin at Vinh Tuy station,
Ha Giang province by using the cross–sectional velocity distribution model and stage-discharge rating
curve. Observed daily water depth and water discharge in the period from 2012 to 2018 are used to
quantitatively determine regression coefficients of the rating curve as well as modeling parameter in the
cross–sectional velocity distribution model. The results showed that root mean square error and mean
absolute error of water discharge are about 10% of observed magnitude of water discharge at the
station, while correlation and Nash-Sufficient coefficients are greater than 0.87 for the stage –
discharge rating curve as well as for both calibration and validation of the cross–sectional velocity
distribution model. Then, both methods are applied to reconstruct and simulate water discharge in the
period from 1972 to 2012. These simulated water discharge will be useful data sources for studying
sustainable exploitation and utilization of water resources as well as assessment of the flow variability
in the Lo river basin under influences of natural and artificial conditions.
Keywords: Lo river, cross–sectional velocity distribution model, Stage-discharge rating curve