What natural force causes water to move through pores in soil and rocks?

The movement of water through pores in soil and rocks is primarily driven by gravity. When water saturates the soil, gravity pulls the water downward, facilitating its movement through the spaces between soil particles and within rock formations. This downward movement is essential for recharging groundwater supplies and influencing the overall hydrology of an area.

While other factors such as capillary action and surface tension play roles in how water behaves at a smaller scale—as seen in the movement of moisture upwards against gravity in soil—gravity remains the dominant force responsible for the bulk movement of water through the larger pores found within soils and rocks. Evaporation, while a crucial process in the water cycle, does not directly contribute to the movement of water through soil and rock. Rather, it changes liquid water into vapor, affecting moisture levels but not the gravitational pull that drives water movement downwards.