Here's why:
* Vadose Zone: This zone lies above the water table and is characterized by unsaturated soil and rock. The spaces between the soil particles are filled with both water and air. As you move deeper into the vadose zone, the air pockets become smaller and the water content increases.
* Saturated Zone: This zone lies below the water table and is where the spaces between soil and rock particles are completely filled with water.
* Capillary Fringe: This is a thin zone above the saturated zone where water is drawn upward due to capillary action, but air pockets still exist.
So, while the capillary fringe has some air, the vadose zone is where you'll find the most air pockets within groundwater.
