There is one additional thing to note. Soil has a certain sponge like quality to absorb water. So a runoff curve number was created to "predict runoff or infiltration"

The tables on the wiki pages shows "curve numbers" for different types of soils. These numbers are based on experimental data which is then used to model runoff. (Or used to be. Its been 20 years since I've done runoff modeling, so maybe things have changed)

https://en.wikipedia.org/wiki/Runoff_curve_number