Chapter 17 Flashcards
(24 cards)
Aquiclude
A relatively impermeable formation that bounds an aquifer above or below and acts as a barrier to the flow of groundwater.
Karst Topography
An irregular, hilly type of terrain characterized by sinkholes, caves, and a lack of surface streams; formed in regions with humid climates, abundant vegetation, extensively jointed limestone formations, and appreciable hydraulic gradients.
Artesian Flow
A spontaneous flow of groundwater through a confined aquifer to a point where the elevation of the ground surface is lower than that of the groundwater table.
Meteoric Water
Rain, snow, or other forms of water derived from the atmosphere.
Discharge
- The volume of groundwater leaving an aquifer in a given time
- The volume of water that passes a given point in a given time as it flows through a channel of a certain width and depth.
Permeability
The ability of a solid to allow fluids to pass through it.
Groundwater
The volume of water that flows beneath Earth’s surface.
Potable
Pertaining to water that tastes agreeable and is not dangerous to human health.
Hydraulic Gradient
The ratio between in elevation between two points in the groundwater table and the flow distance that water travels between the two points.
Precipitation
- A deposit on Earth’s surface of condensed atmospheric water vapor in the form of rain, snow, sleet, hail, or mist
- The condensation of a solid from a solution during a chemical reaction
Hydrology
The science that studies the movements and characteristics of water on and under Earth’s surface.
Rain Shadow
An area of low rainfall on the leeward slope of a mountain range.
Aquifer
A porous formation that stores and transmits groundwater in sufficient quantity to supply wells.
Recharge
The infiltration of water into any subsurface rock formation.
Darcy’s Law
A summary of the relationships among the volume of water flowing through an aquifer in a certain time, the vertical drop of the flow, the flow distance, and the permeability of the aquifer.
Drought
A period of months or years when precipitation is much lower than normal.
Groundwater Table
The boundary between the unsaturated zone and the saturated zone.
Hydrologic Cycle
The cyclical movement of water from the ocean to the atmosphere by evaporation, to the surface by precipitation, to streams through runoff and groundwater, and back to the ocean.
Infiltration
The movement of water into rock or soil through cracks or small pores between particles.
Relative Humidity
The amount of water vapor in the air, expressed as a percentage of the total amount of water the air could hold at the same temperature if it were saturated.
Runoff
The sum of all precipitation that flows over the land surface, including not only streams but also the fraction that temporarily infiltrates near-surface soil and rock and then flows back to the surface.
Saturated Zone
The level below the groundwater table, in which the pores of soil or rock are completely filled with water. AKA the phreatic zone.
Sinkhole
A small, steep depression in the land surface formed when the thin roof of a limestone cave collapses suddenly.
Unsaturated Zone
The level above the groundwater table, in which the pores of the soil or rock are not completely filled with water. AKA the vadose zone.
