Students in Brazil did fieldwork to investigate infiltration. Infiltration is the process by which water soaks into the soil. The students worked in two groups to do their fieldwork in a river valley. They created two transects (A and B) going away from the river. These are shown in Fig. 8 (Insert). The hypotheses investigated by the students were: Hypothesis 1: The infiltration rate decreases as distance from the river increases. Hypothesis 2: The infiltration rate decreases as soil moisture content increases. Soil moisture content is the quantity of water in the soil.