A Study on Rainfall Thresholds for Flood Forecasting in the Danshui River Basin Using the HBV Hydrological Model
FU Zhilong
LIANG Yingru
SONG Nan
ZHANG Jianming
ZHANG Xinyi
Abstract：To enhance flood disaster preparedness in the Danshui River Basin,the HBV(Hydrologiska Byråns Vattenbalansavdelning)hydrological model was employed to simulate runoff using hydrological and meteorological data.The study established relationships among rainfall,discharge,and water level,and in-vestigated critical rainfall thresholds.After calibration and verification,the model performance indices—Nash-Sutcliffe Efficiency Coefficient(NSE)and Water Balance(WB)—both exceeded 0.6,indicating that the HBV model effectively captured the overall trend and peak flood processes of the Danshui River run-off.Based on the water level-discharge relationship,the rainfall-discharge-water level correlation was derived using the discharge outputs from the HBV model.By incorporating antecedent water level data,the water level-rainfall relationship under different initial conditions was determined.The three critical water levels at the Danshui Hydrological Station were then applied to this relationship to establish the corresponding rainfall-antecedent water level thresholds for each critical water level.Finally,the derived thresholds were validated against four historical flood events,with two predictions successful and two unsuccessful.Further analysis revealed that the two failed predictions were primarily due to significant errors in flow simulation,at-tributed mainly to inaccuracies in the empirical parameters related to the runoff coefficient and surface runoff regression coefficient.
Keywords：HBV hydrological modelDanshui Riverrainfall thresholdswater level
Publication Date：2025-10-20
Online Publishing Date：2025-10-30(First online date of this platform, not the publication date of the document)
Pages：5( 12-16 )