Earth's Water Resources Flashcards

Flashcards reviewing key vocabulary and concepts from a lecture on Earth's Water Resources.

Freshwater

Less than 2.7% of global water.

Ice caps and glaciers

Where most freshwater is locked in

Water Cycle Reservoirs

The volume of water stored in various parts of the water cycle (oceans, ice caps, groundwater, etc.)

Major Water Reservoirs

Oceans, ice caps & glaciers, groundwater, lakes, soil moisture, atmosphere, streams & rivers, biosphere

Water Cycle

The continuous movement of water on, above, and below the surface of the Earth.

Hydrologic Cycle

Evaporation, transpiration, sublimation, condensation, precipitation, infiltration.

Major Saltwater Reservoirs

Pacific, Atlantic, Indian, Southern, Arctic

Salinity

The saltiness of saltwater, mainly due to sodium and chloride ions.

Seawater Salinity Range

Varies from 33 to 37 parts per thousand.

Ocean Zones

Littoral, Neritic, Oceanic, Benthic

Ocean Temperature Zones

Surface layer (warm, low density), thermocline (rapid temperature decrease), deep zone (uniformly low temperature).

Surface Level

Consists of relatively warm, low density water, extends from the ocean surface to a depth of 100 m. This is the home of most marine plants and animals

Thermocline

Temperature decreases rapidly with depth.

Deep Zone

The temperature low

Thermohaline Circulation

Located in deep zone which is controlled by temperature and salinity. This circulation is propelled by the sinking of cold, salty, and dense water in the Polar Regions and rising of the warm, less salty water of the tropics.

Glacier

Permanent body of ice consisting of recrystallized snow.

Ice Sheet

Mass of glacial land ice extending more than 50,000 km2.

Ice Cap

Miniature ice sheets, covering less than 50,000 km2.

Ice Shelf

Thick slab of ice attached to a coastline, extending over the ocean

Permafrost

Frozen soil, rock, or sediment for more than two consecutive years.

Surface Water Reservoirs

Streams, lakes and wetlands

Stream

Moving body of surface water flowing downslope toward sea level.

River

Is larger than a stream.

Stream

is shallower than a river.

Creek

is a small stream of water that is inland. It is more turbulent than a stream

Stream Structures

(A) Straight channel, (B) alluvial fans, (C) braided streams, (D) meandering streams, (E) deltas.

Straight channel

Streams occur toward the heads of rivers and at places they cross high ridges. They are often in canyons, though the “canyon” may not be very deep

Alluvial fans

occur at places a stream leaves a

relatively steep area and enters a nearly flat one. The form is very similar to “E”, and for the same reason. If a stream never sees such a drastic change in gradient then no fan will be formed.

Braided streams

Have multiple channels that repeatedly branch and join along the length (“anastomose”) creating many longitudinal bars between the channels. These are usually found close to high mountains and so some streams do not have any braided parts.

Meandering streams

Wander in big loops across a wide flat

floodplain bounded by valley walls.

These are characteristic of lowlands

and so if mountains are too close to

the sea this state may never develop

Deltas

occur where streams enter a standing body of water -- the ocean, usually. If the ocean processes move the sediment as fast as it arrives then no delta will form.

River Components

Source, tributaries, confluence, distributary, floodplain, oxbow lake, river mouth.

Watershed/Drainage Basin

it is a land area in which the water flow into a particular stream.

Lakes

Surface is exposed to the atmosphere and is essentially flat. Water in them came from streams, overland flow and groundwater.

Ponds

Small and shallow lakes.

Dams

Barriers constructed along streams to contain the flow of water.

Wetlands

are land areas where water covers the surface for significant periods. They are biologically diverse environments filled with species that rely on both the land and water for survival.

Marsh

Shallow wetlands around lakes, streams, and oceans where grasses and reeds are the dominant vegetation

Swamp

Wetland with lush trees and vegetation, often found beside slow-moving rivers. Mangrove forests are unique example of the ecosystem that tolerates salty conditions.

Estuary

Partly enclosed coastal body of water where freshwater meets saltwater from the sea. It is home to many organisms that can tolerate the sharp changes in salinity due to constant change in salt content.

Groundwater

Freshwater found in rock and soil layers beneath the surface; largest reservoir of liquid freshwater.

Aquifers

Water-bearing rock layers that hold groundwater in tiny cracks, cavities, and

pores

Aquifer Types

Unconfined aquifer, Confined aquifer and Artesian well

Unconfined Aquifer

Aquifer in which groundwater is free to rise to its natural level

Confined Aquifer

Water is trapped and held down by pressure between impermeable rocks

Artesian Well

Well that doesn’t require a pump to bring water to the surface due to pressure in the aquifer.

China, India, South Africa and Middle East

These countries will face water shortage in the next 20 years

Desalination

Removal of salt from seawater to produce freshwater

The Philippine Clean Water Act of 2004 (R.A. No. 9275)

Protect the country’s water bodies from pollution from land-based sources

Evaporation

Part of the hydrologic cycle where liquid water turns into vapor.

Transpiration

Part of the hydrologic cycle where water is carried through plants from roots to small pores on leaves, where it changes to vapor and is released to the atmosphere.

Sublimation

Part of the hydrologic cycle where a solid turns directly into a gas.

Condensation

Part of the hydrologic cycle where water vapor turns into liquid water.

Precipitation

Part of the hydrologic cycle where water falls from clouds as rain, snow, sleet, or hail.

Infiltration

Part of the hydrologic cycle where water seeps from the surface into the ground.

Source

The origin point of a river.

Tributaries

Smaller streams or rivers that flow into a larger river.

Confluence

The point where two rivers or streams meet.

Distributary

A branch of a river that flows away from the main channel, typically on a delta.

Floodplain

A flat area of land alongside a river that is subject to flooding.

Oxbow Lake

A crescent-shaped lake along a river

River Mouth

The point where a river flows into a lake, sea, or ocean.