What routes allows rain falling on the catchment to reach channel rapidly?

Overland flow: This occurs when rainfall exceeds the infiltration capacity of the soil, causing water to flow over the land surface and into channels. Overland flow is most common in areas with impermeable surfaces, such as paved areas or compacted soils, and in steep areas where water cannot infiltrate the ground quickly enough.

Throughflow: This occurs when water moves through the soil above the water table and into channels. Throughflow is most common in areas with shallow soils or in areas where the water table is close to the surface.

Interflow: This occurs when water moves through the soil below the water table and into channels. Interflow is most common in areas with deep soils and in areas where the water table is below the surface.

Groundwater flow: This occurs when water moves through the ground below the water table and into channels. Groundwater flow is most common in areas with permeable soils and in areas where the water table is below the surface.

Which of these routes is most rapid?

Overland flow is the most rapid route for rain falling on the catchment to reach the channel because it does not involve any infiltration into the soil. Throughflow and interflow are both slower than overland flow because they involve some infiltration into the soil. Groundwater flow is the slowest route because it involves the movement of water through the ground below the water table.