Why surface runoff occur much more often areas with soils with a high clay content?

Surface runoff occurs more often in areas with soils high in clay content because clay has poor permeability, leading to water being unable to infiltrate into the soil. This results in increased surface runoff as the water flows over the impermeable clay layer instead of being absorbed into the ground. Additionally, clay soils have a tendency to become compacted, further reducing infiltration capacity and increasing runoff.