Estimating longitudinal profiles of ordinary water level using gauging station data - a case study: Shonai River, Japan.

Abstract

A simple method was developed to estimate longitudinal profiles of ordinary water level using existing gauging station data and its estimation accuracy was verified by comparison with observed values for the Shonai River, Japan. First in this new method, a longitudinal profile of ＂reference riverbed elevation＂ is created using riverbed elevation data, periodically measured by the river manager. Second, the longitudinal profile of ordinary water level is estimated using the reference riverbed elevation and gauging station water levels. Overall, the estimation accuracy of our method was high. Our new estimations showed higher accuracy than the linear interpolations in the all river segment types (M, 1, 2-1, and 2-2). Our new estimations showed higher accuracy than the uniform flow estimations with simplified roughness coefficients and slopes in the 2-1 and 2-2 segments, and showed similar accuracy to the uniform flow estimations in the M and 1 segments.