Inter-comparison of methods for deriving storage-discharge relation based on streamflow records

Abstract:

Storage-discharge relation is a fundamental characteristic of a watershed. Several methods have been presented in literature to derive the storage-discharge relation based on recession period streamflow data. However, the relative performance of these methods for capturing the storage-discharge relation, which can be used to reconstruct the streamflow time series is not known. Basso et al., [2015] made headway in this direction by comparing three methods for reconstructing streamflow probability distribution. In this study, we inter-compare the performance of four methods for deriving storage-discharge relation. All four methods were applied in more than 40 rain-dominated watersheds in the U.S., and their performances were evaluated by assessing the accuracy of reconstructed streamflow time series. Results indicate that two of the four methods generally outperform the others in the studied watersheds. In addition, the derived storage-discharge relationship is found to be very sensitive to the parameters used in each method, hence one needs to adjust parameters to optimize the performance of each method. Results also indicate that simulated streamflow time series using the derived storage-discharge relation generally captures the overall probability distribution of streamflow, even when the temporal distribution of streamflow magnitudes are not well captured. This suggests that derived storage-discharge relations based on recession periods can not always be used to reconstruct streamflow time series.