“Ground Water Movement” Topic VII “Ground Water Movement”

I. Ground Water: stores of freshwater below the surface of Earth’s landmasses. A. Infiltration: the rate at which surface water moves into the ground.

II. Permeability: soil’s capacity to allow water to flow through it. What’s the relationship between infiltration rate and soil permeability?

A. Factors Affecting Permeability: Slope: steeper slopes create more runoff and decrease permeability.

2. Soil Saturation: if the soil is saturated (filled) with water the ground is less permeable.

3. Impermeable Surfaces: hard surfaces (pavement) that do not allow water to pass.

4. Vegetation: plants slow water movement and increase permeability.

5. Ground Temp.: frozen ground is less permeable.

III. Porosity: the percentage of open space between soil particles. Factors Affecting Porosity: 1. Shape: rounder particle have larger pore spaces between them.

2. Packing: soil that is compressed (packed) tightly has a low porosity. 3. Sorting: soil particles of various sizes (unsorted) have a lower porosity. * Particle size has no affect on porosity, only permeability.

IV. Distribution of Groundwater: A. Zone of Saturation: water completely fills all the pore spaces of the soil. B. Zone of Aeration: located above the saturated zone. C. Water Table: boundary between the saturation and aeration zones.

1. Capillarity: the upward movement of water from the water table 1. Capillarity: the upward movement of water from the water table. (Found just above the water table.) *Smaller particles have greater capillarity.