water cycle
the continuous movement of water from the ocean to the atmosphere to the land and back to the ocean.
tributary
a stream that flows into a lake or into a larger stream.
watershed
the area of land that is drained by a water system.
divide
the boundary between drainage areas that have streams that flow in opposite directions.
channel
the path that a stream follows.
load
the materials carried by a stream.
deposition
the process in which materials are laid down.
delta
a fan-shaped mass of material deposited at the mouth of a stream.
alluvial fan
a fan-shaped mass of material deposited by a stream when the slope of the land decreases sharply.
flood plain
an area along a river that forms from sediments deposited when the river overflows its banks.
water table
the upper surface of underground water; the upper boundary of the zone of saturation.
aquifer
a body of rock or sediment that stores groundwater and allows the flow of groundwater.
porosity
the % of the total volume of rock or sediment that consists of open spaces.
permeability
the ability of a rock or sediment to let fluids pass through its open spaces, or pores.
recharge zone
an area in which water travels downward to become part of an aquifer.
artesian spring
a spring whose water flows from a crack in the cap rock over the aquifer.
point-source pollution
pollution that comes form a specific site.
non point-source pollution
pollution that comes from many sources rather then from a single, specific site, and it is harder to control.
sewage treatment plants
facilities that clean the waste materials found in water that comes from sewers or drains. these sewage plants help protect the environment from water pollution.
septic tank
a tank that separates solid waste from liquids and that has bacteria that break down the solid waste.