Ch. 13

Zone of saturation

The underground area where all the spaces (pores and cracks) in the soil + rock are completely filled with water, forming a large underground reservoir

Water table

Upper surface of the zone of saturation where all available pores in the soil and rock are filled with water.

Aquifers

An underground body of rock or sediment that serves as a storage reservoir for groundwater.

They are essentially pockets of water within the saturated zone, located below the water table

Surface water

Freshwater from rain and melted snow that flows or is stored in lakes, reservoirs, wetlands, streams, and rivers.

Surface runoff

Precipitation that does not soak into the ground or return to the atmosphere by evaporation.

Watershed (drainage basin)

The land from which surface runoff drains into a particular stream, lake, wetland, or other body of water.

Reliable surface runoff

The portion of runoff that is regarded as a stable source of freshwater from year to year.

Water footprint

A rough measure of the volume of freshwater that you use directly or indirectly.

Overpumping

Removing groundwater from rainfall and snowmelt faster than it is replenished.

Land subsidence

The sinking of land that can occur when large amounts of groundwater are withdrawn.

Sinkhole

A depression or hole in the ground caused by the collapse of a surface layer, can swallow cars and houses.

Reverse osmosis (microfiltration)

A process that uses high pressure to remove salt and impurities from saltwater.

Hydrologic cycle

The movement of water in the seas, land, and air, distributed unevenly.

Dam

A barrier that stops or restricts the flow of surface or underground streams.

Reservoir

An artificial lake where water is stored.

Desalination

The process of removing salt from water.

Distillation

The process of purifying a liquid by successive evaporation and condensation.

Floodplain

Flat valley floor next to a stream channel with potential for flooding.

Primary sewage treatment

A physical process where large solids are filtered out and suspended solids settle out as sludge.

Secondary sewage treatment

Biological processes using bacteria that decompose degradable organic wastes in wastewater.

Tertiary or advanced sewage treatment

Special filtering processes, bleaching, and disinfection used to purify water.

Sustainable water use

• use water efficiently

• cut losses

• raise prices

• protect ecosystems

Dead zone

a body of water, an area with extremely low oxygen concentration and very little life

how much water to we waste?

2/3

Depletion of aquifers

-water tables are falling as the rate of pumping water increases(exceeding natural recharge of precipitation)

-drilling of inexpensive tube wells accelerated aquifer overpumping

Virtual water

Water that is not directly consumed but is used to produce food and other products.

Drought

A long period of low precipitation

what increases flooding?

-draining and building on wetlands

-climate change

-removal of water absorbing vegetation

Flood irrigation

Water is pumped from a groundwater or surface water source through unlined ditches where it flows by gravity to the crops being watered

Not efficient… the least inefficient

Dry well

a well that does not supply water because the well has been drilled into an aquitard or into rock that lies above the water table

Surface water flow

runoff stays above ground when surface is not porous or precipitation falls fast

when do floods occur?

when stream overflows its normal channel and spills into floodplain

Fish hatchery

place that collects the eggs and milt from anadromous fish in order to save rare and imperiled fish species and to raise stock fish species

Cuyahoga River

This Ohio river was so polluted that in 1959 and again in 1969 it caught fire and burned for several days as it flowed through Cleveland. Lead to Clean Water Act

LEPA (irrigation)

low energy precision application

Drip irrigation system

*most efficient way to deliver small amounts of water precisely to crop roots; perforated plastic tubes installed underground and emitters drip water at steady rate close to plant roots

Salt water intrusion

near the coast, over-pumping of groundwater causes saltwater to move into the aquifer

riparian buffer

trees and forest planted along stream and riverbanks to absorb nutrients before the nutrients can run into the water

center pivot irrigation

a type of irrigation that waters crops using sprinkler systems on huge turning wheels