Geoscience Reference
In-Depth Information
Carr -
Term used in Europe for a forested
wetland characterized by alder (
Alnus
) and
willow (
Salix
).
Catotelm -
Lower portion of soil and underly-
ing sediment in which oxygen is lacking and
decay is relatively slow. Zone generally below
the long-term average water table.
Chinampa -
Method of building artii cial islands
in shallow lakes in ancient Mesoamerica;
used for growing crops and l owers. Eytmol:
Nahuatl word chinamitl - square made of
canes (
The Free Dictionary
2011).
Coal -
Sedimentary rock and fossil remains con-
sisting primarily of carbon and formed by
compaction and chemical alteration from
vegetation remains. Varieties anthracite, bitu-
minous coal, and lignite differ in density,
carbon percentage, and energy content.
Cost-benei t analysis -
Means of evaluating
the economic costs and benei ts of a develop-
ment project.
Coteau -
Hilly upland forming a drainage divide
often with steeply sloping sides. Applied in
the Great Plains of North America; for
example, Coteau du Missouri and Coteau des
Prairies. Eytmol: French - slope (
The Free
Dictionary
2011).
Crustal depression/rebound -
Subsidence and
uplift of the crust (lithosphere) as a conse-
quence of loading and unloading during ice-
sheet glaciation, which may amount to several
100 m.
Cryosphere -
Frozen portions of the Earth's
surface, including glaciers, ice sheets, perma-
frost, pack ice, perennial snowi elds, etc.
Cumbungi swamp -
Cattail (
Typha
) marsh in
Australia.
Dambo -
Seasonally waterlogged and grass-
covered linear depression located in headwa-
ter zone of rivers with no marked stream
channel or woodland vegetation. Eytmol:
ChiChewa (central Africa) - meadow grazing.
Delta -
Wetland-river-upland complex located
where a river forms distributaries as it merges
into a sea or lake. The delta is built of sedi-
ment delivered by the river; sediment
supplied by river is greater than can be redis-
tributed along the coast or offshore. Also
inland deltas such as the Peace-Athabasca
Delta in Canada and Okavango Delta in
Botswana.
Dhap -
Floating cultivation on mats of dead
aquatic vegetation in wetlands of Bangladesh.
Drainage tile
- Buried drainage pipes designed
to lower water table through gravity l ow
typically installed in agricultural i elds to
promote crop growth.
Duck stamp -
Popular name for the U.S. Migra-
tory Bird Hunting and Conservation Stamp,
which is required for hunting migrating water-
fowl in the United States and is also required
for entering certain U.S. National Wildlife
Refuges.
Ecotourism -
Travel for the purpose of viewing
natural environments and wildlife, bird and
whale watching, etc.
Eemian -
Refers to the high stand of sea level
during the last interglacial period,
130,000
to 120,000 years ago. European term equiva-
lent to Sangamon in North America.
Estuary -
Where a river l ows into the sea in a
deep or wide valley without sufi cient sedi-
ment to build a delta. Fresh and salt water
mix with intermediate salinity, and tides ebb
and l ow within the estuary system.
Eustasy -
Refers to worldwide sea level and
global changes in sea level.
Eutrophic -
Refers to wetland or water with a
high level of nutrients (phosphate, nitrate)
with high primary productivity.
Evaporite -
Deposits resulting from the evapo-
ration of saline water. Highly varied mineral
types depending upon chemical composition
and concentration of evaporating water body.
Evapotranspiration -
Combined water loss
due to evaporation from water bodies and
exposed soils as well as transpiration through
plant bodies.
Externality -
Positive or negative byproducts of
production or exchange that are not part of
the economic market supply and demand.
Facultative -
Refers to hydrophytic vegetation
that often grows in wetland conditions (34-
66%). Also may refer to the transition interval
in soils between aerobic and anaerobic zones.
Fadama -
Floodplains underlain by shallow
aquifers along Nigerian river systems; often
developed for irrigated agriculture.
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