Introduction
Land cover concerns the spatial distribution
of physical cover including vegetation types and human uses
of land for living, agriculture and forestry, and commercial
space.
Land
cover affects and is affected by global climate change in
important ways. First, the interaction of land cover and
the atmosphere causes a regulation of the hydrologic cycle
and energy budget, which makes it necessary for weather
and climate prediction. Land cover also plays a major role
in the carbon cycle by acting as a source and a sink of
carbon. Deforestation, aforestation, and re-growth cause
the release and sequestering of carbon, thereby affecting
atmospheric CO2 concentration and
the strength of the greenhouse effect (GCOS 2004, Masek
2001). Also, because regional climate conditions are a main
determinant of vegetation types, changes in vegetation and
land cover may indicate that climate change is occurring
(GCOS 2004). Finally, land cover is a useful indicator because
many climate-related variables that are difficult to measure
at the global level, such as surface roughness, can be inferred
in part from vegetation and land surface types; thus, land
cover can be used to infer other important climate variables
(GCOS 2003).
As a
subset of the land cover variable, monitoring of land cover
change is necessary for understanding the extent and severity
of anthropogenic and natural changes occurring. Land cover
changes may be grouped into one of two broad categories:
conversion or modification. Conversion refers to the change
from one cover type to another, such as conversion of forests
to pasture land. Modification refers to the maintenance
of the same cover type while changes to its attributes are
occurring. For instance, a forested area may be retained
as forest while major impacts to its structure or function,
such as those involving biomass or productivity, occur (LUCC
1997).
Land
cover products have historically been developed according
to specific project needs, with methods and results generally
not compatible across different land cover schemes. This
tendency has resulted in the development of remote sensing
datasets and methods that are difficult to compare, both
spatially and temporally. (Homer 2004) With regard to land
cover change, the monitoring process requires the existence
of (reasonably) reliable maps and datasets to construct
a time series for land cover over a particular area. Traditional
cartography provides some historical context, but because
many of these land cover products have not been properly
archived and transferred into electronic format, it is difficult
to construct an accurate time series.
Historic
background
Land
cover has been identified as a terrestrial essential climatic
variable in the original GCOS implementation plan and adequacy
reports.
Information
on the requirements and status of the land cover ECV which
have already been submitted to the UNFCCC is summarized
in the following
document 73kb,
v01, 22 June 2007
ECV
land cover standards report
GTOS
is currently assessing the status of the development of
standards for each of the essential climate variables in
the terrestrial domain, as requested by UNFCCC SBSTA/COP
for its 23rd Session in Montreal, November 2005. The following
report, documentation and other resources have been compiled
for land cover. We welcome your comments and inputs in improving
and completing the analysis for biomass. Please send any
material and comments to the GTOS
Secretariat.
References
Listed
below are the major references that have been identified
in regards to methodology and standards for land cover.
Please inform us if you are aware of any other documentation
or material which could be considered.
CEOS
Earth Observation Plans, Surface temperature (land). ECV-T9-landcover-ref22
CEOS
Earth Observation Plans, Multipurpose imagery (land). ECV-T9-landcover-ref23
Ciais,
Ph. et al. Integrated Global Carbon Observation
Theme: A Strategy to Realize a Coordinated System of Integrated
Global Carbon Cycle Observations. Version 10. ECV-T9-landcover-ref24
Cohen,
W.B., T.K. Maiersperger, T.A. Spies, D.R. Oetter. Modelling
forest cover attributes as continuous variables in a regional
context with Thematic Mapper data. International Journal
of Remote Sensing, 2001, 22(12): 2279-2310. ECV-T9-landcover-ref16-Cohen
FAO.
2005. Land Cover Classification System: Classification concepts
and user manual. Environment and Natural Resources Series.
No. 8. Rome. ECV-T9-landcover-ref25
Global
Climate Observing System. 2003. 2nd Report on Adequacy of
Global Observation Systems. GCOS-82, WMO/TD No. 1143. ,
85 pp. ECV-T9-landcover-ref02
Global Climate
Observing System. 2004. Implementation Plan for the Global
Observing System for Climate in Support of the UNFCCC. WMO/TD
No. 1219.
ECV-T9-landcover-ref01
Hansen,
M.C. and B. Reed. 2000. A comparison of the IGBP DISCover
and University of Maryland 1 km global land cover products.
International Journal of Remote Sensing, 21(6 & 7):
1365-1373. ECV-T9-landcover-ref14
Herold,
M., Latham, J.S, Di Gregorio, A, and Schmullius, C.C. 2006.
Evolving standards in land cover characterization. Journal
of Land Use Science. Journal of Land Use Science, 1(2-4):
157-168. ECV-T9-landcover-ref17
Homer,
Collin, Chengquan Huang, Limin Yang, Bruce Wylie, and Michael
Coan. 2004. Development of a 2001 National Land-Cover Database
for the United States. Photogrammetric Engineering &
Remote Sensing, 70(7): 829-840. ECV-T9-landcover-ref05
Integrated
Global Observing Strategy Partnership. 2004. Integrated
Global Observations of the Land – A proposed theme
to the IGOS-Partnership-Version 2. IGOS-P 11 Doc., Item
7.1., 11pp. ECV-T9-landcover-ref10
LUCC
Data Requirement Workshop: Survey of needs, gaps and priorities
on data for land use/land cover change research, LUCC Report
Series No.3, Organised by IGBP/IHDP-LUCC and IGBP-DIS, Barcelona,
Spain, 11-14 Nov. 1997, 143 pp. ECV-T9-landcover-ref18
Masek,
Jeffrey G., Mark Friedl, Thomas Loveland, Eric Brown de
Colstoun, John Townsend, Matthew Hansen, K. Jon Ranson.
Land Cover/ Land Cover Change ESDR. ECV-T9-landcover-ref04
NASA.
Earth Observatory Glossary. ECV-T9-landcover-ref07
NASA.
The
Earth Science Technology Integrated Planning System (ESTIPS).
Panigrahy,
S., Chakraborty, M., Sharma, S.A., Kundu, N., Ghose, S.C.,
and Pal, M. 1997. Early estimation of rice area using temporal
ERS-1 synthetic aperture radar data – a case study
for the Howrah and Hughly districts of West Bengal, India.
International Journal of Remote Sensing, 18(8): 1827-1833.
ECV-T9-landcover-ref20
Scott,
G., Klaric, M., and Shyu, Chi-Ren. 2005. Modeling Multi-object
Spatial Relationships for Satellite Image Database Indexing
and Retrieval. Chapter in Leow, W.K. et al. (Eds.), Image
and Video Retrieval, Springer-Verlag Berlin Heidelberg,
pp. 247-256. ECV-T9-landcover-ref21
Skole,
D.L., W.A. Salas, and V. Taylor. 1998. Global Observation
of Forest Cover: Fine Resolution Data and Product Design
Strategy, Report of a Workshop. GTOS. GOFC-GOLD Report No.
4. Paris, France. ECV-T9-landcover-ref12
Strahler,
Alan H., et al. 2006. Global Land Cover Validation: Recommendations
for Evaluation and Accuracy Assessment of Global Land Cover
Maps. European Communities, Luxembourg. ECV-T9-landcover-ref15
TEMS
variable database. ECV-T9-landcover-ref09
United
Nations Framework Convention on Climate Change. 2006. Proposal
for possible revision of the UNFCCC reporting guidelines
on global climate change observing systems: Submission from
the Global Climate Observing System secretariat. Subsidiary
Body for Scientific and Technological Advice, United Nations
Framework Convention on Climate Change, 12 September 2006.
ECV-T9-landcover-ref03
Multi-Resolution Land Characteristics Consortium, National
Land Cover Database 2001 (NLCD 2001). ECV-T9-landcover-ref26
Van, Tran Thi. Relationship Between Surface Temperature
and Land Cover Types Using Thermal Infrared Remote Sensing,
in Case of HoChiMinh City. Institute for Environment and
Resources, Vietnam National University, Ho Chi Minh City.
ECV-T9-landcover-ref08
Varlyguin,
Dmitry L., Robb K. Wright, Scott J. Goetz, Stephen D. Prince.
2001. Advances in land cover classification for applications
research: a case study from the mid-Atlantic Resac. ECV-T9-landcover-ref11
Relevant
Web links
Listed
below are links relevant to land cover measurements. New
links are welcome:
CARBOAFRICA
Center for
Tropical Forest Service
Chinese
Ecosystem Research Network
Chinese
Forest Ecosystem Research Network
Committee
on Earth Observation Satellites
Earth Resources
Observation and Science (EROS), United States Geological
Survey
Ecological
Monitoring and Assessment Network
European
Network for long-term Forest Ecosystem and Landscape Research
European
Space Agency
GOFC-GOLD
Global
Land Cover Facility
Global
Observing System Information Center, Global Change Master
Directory Portal
Global
Observation System Information Center, Land Surface, Land
Cover
International
Cooperative Programme on Integrated Monitoring of Air Pollution
Effects on Ecosystems
Integrated
Global Observing Strategy, Integrated Global Carbon Observation
International
Long Term Ecological Research
Land
Cover Institute, United States Geological Survey
Multi-Resolution
Land Characteristics Consortium
Universität
Jena, Institute for Geography
University
of Maryland, College Park, Department of Geography
US Long
Term Ecological Research
