Hydrological Model Supported by a Step-Wise Calibration against Sub-Flows and Validation of Extreme Flow Events
Loading...
Date
2019
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Water
Abstract
Most hydrological models have fixed structures and their calibrations are typified by a
conventional approach in which the overall water balance closure is considered (without a step-wise
focus on sub-flows’ variation). Eventually, hydrological modelers are confronted with the difficulty of
ensuring both the observed high flows and low flows are accurately reproduced in a single calibration.
This study introduced Hydrological Model focusing on Sub-flows’ Variation (HMSV). Calibration
of HMSV follows a carefully designed framework comprising sub-flow’s separation, modeling of
sub-flows, and checking validity of hydrological extremes. The introduced model and calibration
framework were tested using hydro-meteorological data from the Blue Nile Basin of Ethiopia in
Africa. When the conventional calibration approach was adopted through automatic optimization
strategy, results from the HMSV were found highly comparable with those of five internationally
well recognized hydrological models (AWBM, IHACRES, SACRAMENTO, SIMHYD, and TANK).
The new framework enhanced the HMSV performance for reproducing quantiles of both high flows
and low flows. The combination of flow separation and step-wise calibration of hydrological model
against sub-flows enhances the modeler’s physical insight in identifying which areas need focus
in modeling to obtain meaningful simulation results, especially of extreme events. The link for
downloading the HMSV is provided.
Description
Keywords
Rainfall-runoff model, Blue Nile, Baseflow separator, Discharge splitting, Hydrological model, Hydrological extremes
Citation
Onyutha, C. (2019). Hydrological model supported by a step-wise calibration against sub-flows and validation of extreme flow events. Water, 11(2), 244. doi:10.3390/w11020244