Land Cover & Land Use
Although the terms land cover and land use are often used interchangeably, their
actual meanings are quite distinct. Land cover refers to the surface cover on the ground,
whether vegetation, urban infrastructure, water, bare soil or other. Identifying,
delineating and mapping land cover is important for global monitoring studies, resource
management, and planning activities. Identification of land cover establishes the
baseline from which monitoring activities (change detection) can be performed, and
provides the ground cover information for baseline thematic maps.
Land use refers to the purpose the land serves, for example, recreation, wildlife
habitat, or agriculture. Land use applications involve both baseline mapping and
subsequent monitoring, since timely information is required to know what current quantity
of land is in what type of use and to identify the land use changes from year to year.
This knowledge will help develop strategies to balance conservation, conflicting uses,
and developmental pressures. Issues driving land use studies include the removal or
disturbance of productive land, urban encroachment, and depletion of forests.
It is important to distinguish this difference between land cover and land use, and
the information that can be ascertained from each. The properties measured with remote
sensing techniques relate to land cover, from which land use can be inferred,
particularly with ancillary data or a priori knowledge.
Land cover / use studies are multidisciplinary in nature, and thus the participants
involved in such work are numerous and varied, ranging from international wildlife and
conservation foundations, to government researchers, and forestry companies. Regional (in
Canada, provincial) government agencies have an operational need for land cover inventory
and land use monitoring, as it is within their mandate to manage the natural resources of
their respective regions. In addition to facilitating sustainable management of the land,
land cover and use information may be used for planning, monitoring, and evaluation of
development, industrial activity, or reclamation. Detection of long term changes in land
cover may reveal a response to a shift in local or regional climatic conditions, the
basis of terrestrial global monitoring.
Ongoing negotiations of aboriginal land claims have generated a need for more
stringent knowledge of land information in those areas, ranging from cartographic to
thematic information.
Resource managers involved in parks, oil, timber, and mining companies, are concerned
with both land use and land cover, as are local resource inventory or natural resource
agencies. Changes in land cover will be examined by environmental monitoring researchers,
conservation authorities, and departments of municipal affairs, with interests varying
from tax assessment to reconnaissance vegetation mapping. Governments are also concerned
with the general protection of national resources, and become involved in publicly
sensitive activities involving land use conflicts.
Land use applications of remote sensing include the following:
- natural resource management
- wildlife habitat protection
- baseline mapping for GIS input
- urban expansion / encroachment
- routing and logistics planning for seismic / exploration / resource extraction
activities - damage delineation (tornadoes, flooding, volcanic, seismic, fire)
- legal boundaries for tax and property evaluation
- target detection - identification of landing strips, roads, clearings, bridges,
land/water interface
"...let me make this perfectly clear..."
Calgary (Landsat-TM)
This is a TM scene of Calgary, Canada, where the 1988 Winter Olympics were held.
Calgary appears quite blue; the agricultural fields to the east are red, while grazing
land to the west is green. Abutting the southwest corner of the city, is a long
rectangular section of land stretching towards the west that is darker and more monotone
than the other areas around it. This is the area of the Sarcee Reserve (T'suu T'ina)
which has been held by native people, and protected from urbanization and residential
construction. Of all the land on the image, this land is the closest to the original
state of the Calgary region before agriculture and settlements reworked the landscape. It
looks like an oasis amidst suburbia and farmland.
More alien circles?
These are even stranger circles than the ones we first encountered. The outer circles
are tens of kilometers across. What could have created this shape, and other than being a
landing target for UFOs, what possible land use could it serve?
The answer is ...
You had a good guess if you thought these circles were created by an ancient
civilization, like the Aztecs, or it represents a giant teepee ring. But it's not
correct. Try again.
The circles are part of a military base in southern Alberta. The land is used for
practice maneuvers and is "protected" from the ranging and farming on nearby dry
grassland. The circles identify radial distances from 'ground zero', where various real
and simulated explosions were conducted by the military.