Integrated Hydrologic and Hydrodynamic Models to Improve Flood Simulation Capability in the Data-Scarce Three Gorges Reservoir Region

Yulong Zhang,Chengwei Lu,Jianzhong Zhou

doi:10.3390/w12051462

Abstract

One-dimensional hydrodynamic modeling approaches are useful for flood simulations; however, most studies often neglect intermediate discharges due to difficulties in obtaining the associated data. Herein, we produced the XAJ-H1DM model by coupling the Xinanjiang (XAJ) model, without the Muskingum module, with a one-dimensional hydrodynamic (H1DM) model, using regionalization approaches to test their practicality. Another model, named H1DM-XAJ, was also produced by orderly calibrating the H1DM and XAJ models to achieve improved flood simulations in poorly gauged catchments. The flood simulation capabilities of the four models (including the single XAJ and H1DM models) were investigated and compared at a daily time scale in the Three Gorges Reservoir Region, China. The results show that the regionalization approaches can be successfully used in the application of the integrated hydrologic and hydrodynamic model in ungauged intermediate catchments. Further, the coupled models produced markedly improved estimates of peak discharge and runoff volume compared to the single models. Moreover, the ability of the coupled models to simulate the peak water level and hydrograph, which hydrological models lack, is significantly better than that of the single H1DM model. The framework presented can be applied in other data-scarce catchments worldwide for better understanding of the hydrodynamic processes.

Highlights

Floods are one of the most serious natural disasters associated with water, causing severe property damage and loss of life
The accuracy statistics of flow for the four models are summarized in Table 3, which shows the absolute means with respect to the relative runoff volume error (RRE), relative peak discharge error (RPE), peak time error (PTE), and Nash–Sutcliffe efficiency (NSE) values for the calibration and validation periods
For the H1DM model, the absolute means of the RRE and RPE simulations for the four study regions range from −10.19% to −2.3% and −20.56% to 0.78%, while the PTE is always 0 days (Table 2)

Summary

Introduction

Floods are one of the most serious natural disasters associated with water, causing severe property damage and loss of life. The growing necessity of these operational systems has promoted the development of hydrodynamic models, which are commonly used in the existing systems [1,2]. With the rapid development of computational technologies, a large number of studies on hydrodynamic models for flood simulations and forecasting have been carried out over the past several decades [3,4,5,6,7,8,9,10,11,12,13]. The more thorough the secondary processing integration, the tighter the coupling simulation system integration. According to the ease of the secondary development in question, secondary processing integration can be divided into four categories: non-integrated, loosely coupled, tightly coupled, and fully integrated [14].

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Discussion

Conclusion