Prediction of Streamflow Recession Curves in Gauged and Ungauged Basins
Shailesh Kumar Singh, George A. Griffiths
Abstract
Abstract Prediction of the time for perennial outflow from a natural basin to recede from the mean to some low flow value is an important practical and difficult problem in water resource management. This study aims to gain further understanding of this complex problem and to put forward new practical and accurate methods for predicting flow recessions between nominated limits in both gauged and ungauged basins. For a gauged basin, a three parameter recession model is employed to estimate the recession time, from day‐to‐day, as flow recedes from mean flow using previously measured site recession curves and a library of recession curve shapes generated by the RObust Parameter Estimation algorithm. The model is tested using data from 10 New Zealand basins which are diverse in low flow hydrological behavior and yields a Median Absolute Error (MAE) of 1 day. Another new model is also developed to predict recession time in an ungauged basin using catchment characteristics and information from master recession curves in a suite of 10 reference basins geologically and hydrologically similar to the ungauged basin, as assessed by a Random Forest model. Model performance is robust with a MAE of 1 day and the models advance the use of past flow records to enable more accurate predictions to be obtained. They can be applied elsewhere with confidence although further testing is desirable.