New method to calculate the dynamic factor-flow velocity in Geomorphologic instantaneous unit hydrograph

Area of Science:

• Hydrology
• Geomorphology
• Water Resource Management

Background:

• Accurate flow velocity estimation is crucial for runoff simulation using the geomorphologic instantaneous unit hydrograph (GIUH) model, especially in regions with limited hydrological data.
• Existing methods for determining flow velocity often require extensive data, posing a challenge for practical applications.

Purpose of the Study:

• To develop a robust regression model for estimating characteristic flow velocity based on geomorphological factors.
• To enhance the application of the GIUH model for runoff simulation in data-limited watersheds.

Main Methods:

• Utilized 120 watersheds for model development and validation.
• Applied Random Forest algorithm to identify key geomorphological factors influencing flow velocity.
• Employed multivariate regression to establish a quantitative relationship between flow velocity and selected factors.
• Conducted sensitivity analysis using the LH-OAT method.

Main Results:

• Identified significant geomorphological factors affecting flow velocity.
• Developed a regression model demonstrating high fitting accuracy for flow velocity calculation.
• Validated the model's feasibility and rationality against previous approaches.
• Successfully improved runoff simulation accuracy using the GIUH model with the proposed flow velocity estimation technique.

Conclusions:

• The developed regression model provides an accurate and practical method for estimating characteristic flow velocity.
• The proposed technique enhances the utility of the GIUH model for runoff simulation in data-scarce environments.
• This approach offers a valuable tool for hydrological analysis and water resource management.