Influence of Calibration Parameter Selection on Flash Flood Simulation for Small to Medium Catchments with MISDc-2L Model

Ngoc Tu Nguyen,Yonghua Zhu,Haishen Lü,Wei He

doi:10.3390/w12113255

Abstract

It is of great challenge to accurately predict flash floods for small to medium catchments (SMC) in mountainous areas, for which parameter calibration strategies are crucial for model performance. This study investigates the influence of calibration parameter selection on flash flood simulations using a rainfall–runoff model, MISDc-2L (Modello Idrologico Semi-Distribuito in continuo–2 layers), at hourly scale for SMC in the Huai River basin of China over the 2010–2015 period. We investigated model performances under different calibration schemes, where different amounts of model parameters were selected for the calibration procedure. The model clearly performed better in the case involving calibration of partial sensitive parameters than that of a full parameter set with respect to the peaks, the hydrographs and the base-flow of flood simulation, especially after including maximum water capacity (W_max) in the calibration. This finding was consistently valid under different model calibration experiments, including single event, “split-sample” test and combined events at different flood magnitude levels. We further found that the model performed better for high magnitude flood events than medium and low ones, but clear improvements can be achieved for low and medium magnitude flood events with careful calibration parameter selection. Our study suggests that calibration parameter selection is important for flash flood event simulations with the MISDc-2L model for SMC in the Huai River basin of China; specifically, the reduction in calibration parameter amount and the inclusion of W_max in calibration remarkably improve flood simulation.

Highlights

In recent decades, flash floods have become one of the most severe natural hazards in the context of global climate change [1,2]
This study aims to investigate the influence of calibration parameter selection on flash flood simulation for small to medium catchments with the MISDc-2L model in the Huai River basin of
We focus on three main research questions: (1) How effective is the MISDc-2L model for flash flood simulations at hourly time-steps in the Huai River basin of China? (2) Is the reducing of the amount of calibration parameters favorable for streamflow simulation? (3) Does the inclusion of parameter maximum water capacity on calibration lead to the improvement in flood simulations with the MISDc-2L model? To address these questions, the paper is organized as follows: Sections 2 and 3 describe the study area, data and methodology including model structure and model constraining strategies, Section 4 presents the results about model applicability with different calibration schemes, and Section 5 includes the discussion and Section 6 provides conclusions

Summary

Introduction

Flash floods have become one of the most severe natural hazards in the context of global climate change [1,2]. With increasing intense precipitation over highly saturated soils in mountainous terrain, flash flooding events are likely to be more frequent over the globe [6]. Water 2020, 12, 3255 which urgently calls for the development of effective models and calibration methods for predicting flash floods [7]. Numerous hydrological models with simple to complex structures were developed as a useful tool to deal with flood simulation [8]. Distributed models consider the spatial distribution of land surface features, e.g., the Digital Elevation Model (DEM) and land cover type, it has a complex structure and requires intensive computation. Lumped models have a simple structure and require low computation, which proves that they effectively simulate flood events in small catchments (

Objectives

Results

Discussion

Conclusion