Discharge estimation for medium-sized river using multi-temporal remote sensing data: a case study in Brazil

Abstract

ABSTRACT The increased availability of remote sensing data associated with good revisit capabilities promotes the use of these data to estimate hydrological variables such as river width. This becomes especially useful for regions with poor coverage of in situ stations. In this study, we propose a methodological approach to estimate river discharge from time series of river width. The discharge from in situ hydrological stations was regionalized to calibrate a series of width-discharge models of three different types using theoretical hydraulic geometry power functions. Our methods used both individual and average width to estimate discharge. It was found that a priori selected average widths yielded models with better adjustment than the systematic average or the individual width approaches. Nearly 70% of the models generated with the selected average widths produced Nash-Sutcliffe efficiency values better than 0.7. The article explores the implications of estimating discharge from width and describes the method used.