ERSC 1F90 Lecture Notes - Lecture 9: Hydraulic Head, Aquifer, Superheated Water
9 Apr 2015
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Document Summary
Groundwater represents the largest reservoir of fresh (potable) water that"s readily available. Groundwater: water that completely fills void spaces in sediment and rock in the zone of saturation. The upper limit of this zone is the water table. Infiltration: process by which precipitation moves downward through earth materials. Infiltration replenishes soil moisture, recharges aquifers and supports streamflow during arid intervals. Aquifer: subsurface layer of saturated permeable rock or unconsolidated sediment from which groundwater can be usefully extracted using a well. Impermeable layers (eg. clay) that hinder water movement are called aquitards: water level in wells coincides with the water table. Groundwater tends to move perpendicular to the contours and down the slope of the water table. The hydraulic gradient is determined by measuring the difference in elevation between 2 points on the water table divided by the difference between them: hydraulic gradient = water table slope.
