Performance of long-term continuous hydrological models in fluvial flow simulation in a large-scale river basin

Area of Science:

• Hydrology
• Environmental Science
• Water Resource Management

Background:

• Hydrological models are essential for flood risk management and understanding environmental change impacts.
• Continuous hydrologic modeling aids in assessing long-term hydrologic processes and environmental shifts.
• Selecting reliable hydrological models is critical for effective basin flood risk management.

Purpose of the Study:

• To compare the performance of the Soil and Water Assessment Tool (SWAT) and the Hydrologic Engineering Centers' Hydrologic Modeling System (HEC-HMS).
• To evaluate their suitability for long-term continuous hydrological simulations in large river basins.
• To assess their effectiveness in predicting river discharge and managing flood risk.

Main Methods:

• Conducted long-term continuous simulations using both SWAT and HEC-HMS in the Pearl River Basin.
• Utilized identical input data and comparable model configurations for a fair comparison.
• Employed the Nash-Sutcliffe efficiency coefficient to evaluate model performance.

Main Results:

• Both SWAT and HEC-HMS demonstrated satisfactory river discharge prediction capabilities (Nash-Sutcliffe coefficient > 0.7).
• SWAT achieved higher accuracy during the validation period due to its modified Soil Conservation Service (SCS) loss model and advanced calibration.
• HEC-HMS offers customizable options and shows potential for large-scale basin applications.

Conclusions:

• Both hydrological models are effective for continuous simulations and discharge prediction in large basins.
• SWAT provided more accurate results, while HEC-HMS offers greater flexibility in model construction.
• HEC-HMS shows significant potential for long-term hydrological simulations in extensive river systems like the Pearl River Basin.