Kit Lesson 6: Where Does the Water Go? Looking at Ground Water and Runoff (PT)
Rain is pulled down hillsides and slopes as a result of gravity, runoff refers to the water that flows over the surface of land. Ground water is the water that soaks into the soil and seeps gradually downward. When groundwater flows (more or less vertical) into soil it moves through spaces (pore space) but may each an impermeable layer of rock that is already saturated with water which causes the water level in the soil to rise creating two distinct underground layers. The lower layer is filled with water (zone of saturation) while the upper layer (zone of aeration) contains air and water. The boundary between the two zones is the water table. Wells are often drilled to obtain ground water (used for irrigation,urban development) which cannot all be replaced by precipitation. Pore space and ground water will be compared)