Study on stage-discharge relationship of Atrai river

Abstract

The present study investigated the stage-discharge relationship of the Atrai river. The analysis of stage-discharge relations for four stations: Panchagarh, Bushirbandar, Mohadebpur and Atrai were carried out. Both power type and parabolic equations were selected for establishing stage-discharge relations. Annual rating curves were established for each station. It was found that no substantial shifting control had occurred. Stage-discharge curves of different stations for the same year were investigated so as to establish a correlation between them; however no correlationship could be established. Test for bias and goodness of fit were also applied to investigate the reliability of both power type and parabolic stage-discharge relations. All the equations were found to be free from bias and most cases dispersion of the measured data about the fitted rating curve were fOlmdto be even and within five percents of significant level. In most cases parabolic equations fitted well than the power type .equations. For extrapolation purpose parabolic equations were found better than that of power type equations. For small range of gauge height, power type equations gave better results than parabolic equations. Mean depth discharge relations were also established using both for power type and parabolic equations. But power type and parabolic equations of stage-discharge relation fitted better compared to those of mean depth-discharge relationship.