Runoff is precipitation that did not get (infiltrated) absorbed into the soil, or did not evaporate, and therefore made its way from the ground surface into places that water collect. runoff causes erosion, and also carry chemicals and substances on the ground surface along to the rivers where the water ends up. it can cause water pollution too. read the prompt and study the diagram above. what cause and effect prediction can be used to test the assumptions in the model? a) subsurface flow creates evaporation. b) more precipitation creates less runoff. c) more precipitation creates more runoff. eliminate d) all runoff gets absorbed into the soil.