EPSC 201 Lecture 21 - November 22, 2018 Groundwater is a major component of the hydrologic cycle, and is largely hidden from view. Groundwater provides of freshwater resources; drinking water, agriculture, industry. ⅔ Aquifers & Aquitards Aquifers and aquitards are commonly interlayered. - Aquifer: sediment or rock that transmits water easily - Aquitard: impermeable or low permeability sediment or rock that hinders water flow Unconfined: an aquifer that intersects the surface, in contact with the atmosphere. Easily contaminated. Confined: an aquifer beneath an aquitard, isolated from the surface. Less susceptible to pollution. The Water Table The water table is a subsurface boundary. Above, pores are mostly filled with air. Below, pores are filled with water. The capillary fringe separate the two zones. The depth to the water table varies. In humid settings, it is closer to the surface. In arid settings, it may be tens to hundreds of meters down. The water table is a sloping surface, it is high where the land is high, and low where the land is low. Water flows from higher elevations to lower. Topography is useful for estimating groundwater flow.
- Fall '09
- hot springs