Hillslope Storm Runoff Lab: Green-Ampt Infiltration, Manning Sheet Flow and the Hydrograph

What Hillslope Storm Runoff Lab Is

The Hillslope Storm Runoff Lab simulates rainfall events on a 3D hillslope, illustrating the complex interactions between precipitation, soil properties, and topography. By adjusting factors such as soil type, land cover, slope angle, and storm intensity, users can observe how these variables affect water infiltration and runoff.

This simulation is particularly useful for understanding the Green-Ampt model of infiltration, which describes the rate at which water enters the soil, and Manning's equation, which predicts the velocity of sheet flow over a flat surface.

Why It Matters

Understanding hillslope storm runoff is essential for hydrologists, environmental scientists, and engineers to manage water resources effectively. Proper management can help prevent soil erosion, reduce flood risks, and ensure sustainable land use.

The lab also aids in the design of drainage systems, urban planning, and agricultural practices that minimize negative impacts on local ecosystems.

Key Concepts: Green-Ampt Infiltration and Manning Sheet Flow

Green-Ampt infiltration is a widely used model to predict how much water can be absorbed by the soil during a rainfall event. The model accounts for both initial loss (evaporation, interception) and subsequent infiltration rates based on the soil's moisture content.

Manning's equation, on the other hand, calculates the velocity of sheet flow over a flat surface using parameters such as the slope of the land, roughness coefficient, and hydraulic radius. Together, these models help predict the hydrograph, which is a graphical representation of how runoff volume changes over time.

Real-World Applications

The principles demonstrated in the Hillslope Storm Runoff Lab are applied in various fields, including urban drainage design, agricultural water management, and flood risk assessment. For instance, engineers use these models to design stormwater systems that can handle peak flows without causing flooding.

Environmental scientists also rely on these concepts to study the impact of land use changes on local hydrology, helping to inform policies for sustainable development.

Frequently asked questions

Try it live

Everything above runs in your browser — open Hillslope Storm Runoff Lab: Green-Ampt Infiltration, Manning Sheet Flow and the Hydrograph and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.