Simulation of Runoff Hydrograph on Soil Surfaces with Different Microtopography Using a Travel Time Method at the...

Area of Science:

• Hydrology
• Soil Science
• Geomorphology

Background:

• Understanding surface runoff is crucial for water resource management and erosion control.
• Soil microtopography significantly influences runoff generation and flow paths.
• Existing models may not fully capture the complexities of microtopographical effects on runoff.

Purpose of the Study:

• To propose a simple travel time-based model for simulating runoff hydrographs.
• To evaluate the model's performance on soil surfaces with varying microtopographies.
• To provide a tool for better prediction of hydrological responses in complex terrains.

Main Methods:

• Developed a travel time-based model incorporating rainfall intensity, mean flow velocity, and depression ponding time.
• Utilized a digital elevation model (DEM) to delineate grid cells and calculate flow paths and lengths.
• Estimated flow velocity based on upstream flow accumulation area.
• Calculated total travel time by summing flow path times and ponding time.
• Determined runoff rate by aggregating contributing cell rainfall over time intervals.

Main Results:

• The model successfully simulated runoff hydrographs based on travel time.
• Positive agreement was observed between measured and predicted runoff hydrographs.
• The model demonstrated effectiveness in handling different soil microtopographies.

Conclusions:

• The proposed travel time-based model is a viable tool for simulating surface runoff.
• The model's accuracy highlights the importance of considering microtopography in hydrological studies.
• This approach offers a simplified yet effective method for hydrograph simulation.