overland flow

hydrology

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July 1, 2026

Quick Summary

In hydrology, overland flow refers to the movement of water over the land surface. This occurs when rainfall intensity exceeds the soil's infiltration capacity, causing excess water to collect and flow. This flow is often inefficient due to resistance from the land surface. Overland flow can eventually form channels, leading to stream development.1

The total amount of runoff, which includes overland flow, interflow, and groundwater discharge into streams, is determined by subtracting losses from precipitation. These losses include evapotranspiration, storage, and other abstractions. Understanding overland flow is crucial for managing water resources and predicting stream discharge.23

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hydrosphere
Groundwaters and river runoff
Overland flow is generated at a point on a hillslope only after surface ponding takes place. Ponding cannot occur until the surface soil layers become saturated. It is now widely recognized that surface saturation can occur because of two quite distinct mechanisms—specifically, Horton overland flow…
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Overland flow is generated at a point on a hillslope only after surface ponding takes place. Ponding cannot occur until the surface soil layers become saturated. It is now widely recognized that surface saturation can occur because of two quite distinct mechanisms—specifically, Horton overland flow…
Read More

wastewater treatment
Land treatment
In overland flow, wastewater is sprayed onto an inclined vegetated terrace and slowly flows to a collection ditch. Purification is achieved by physical, chemical, and biological processes, and the collected water is usually discharged into a nearby stream.
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In overland flow, wastewater is sprayed onto an inclined vegetated terrace and slowly flows to a collection ditch. Purification is achieved by physical, chemical, and biological processes, and the collected water is usually discharged into a nearby stream.
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