NATIONAL LAND COVER AND RESOURCE STATISTICS
A. B. Nilsen, K. Bjorkelo
Norwegian Forest and Landscape Institute, PO Box 115, 1431 As, Norway - (ban, kbj)@skogoglandskap.no
KEY WORDS: Land Cover, Statistics, Change Detection, Automation, Open Systems, Internet
ABSTRACT:
An overall societal aim is to ensure a sustainable use and management of a country's land resources. This requires continuous deliv-
ery of reliable and up-to-date information to decision-makers. To be able to deliver this information the Norwegian Forest and Land-
scape Institute (Skog og landskap) produces, among others, land resource statistics for all municipalities in Norway. The statistics are
also produced on a county level and for the whole country. The acreage numbers are retrieved from a combination of different na-
tional datasets in various scales together with interpretation of satellite images. Through a reclassification, statistics are calculated for
certain land resource classes like arable land, pasture, forest based on productivity class, fresh water, snow and glacier, mountain-
ous/scarcely vegetated area and built up area. Skog og landskap has for the last couple of years been using open source software. The
whole statistics production line is carried out by the means of such software. The results are stored in XML -files that are published
on the internet. The production requires processing of several databases with national coverage, and needs to handle geometric opera-
tions efficiently and without error. The open software solution is reliable, stable and fast.
1. BACKGROUND
To understand the relationship between land use and
environmental impacts, information is needed at different scales
- global, European, national and local.
In Norway many different institutions are gathering information
about and monitoring different aspects of the Norwegian society
and environment, e.g. Statistics Norway, The Norwegian
Directorate for Nature Management, Norwegian Water
Resources and Energy Directorate, The Geological Survey of
Norway and The Norwegian Forest and Landscape Institute
(Skog og landskap). Skog og landskap is conducting research
and providing information about the forest, soils, outfields and
landscapes for the mainland. The total area of Norway's
mainland is 324 000 km”.
Skog og landskap was responsible for delivering the CORINE
Land Cover (CLC) dataset for ycar 2000 and 2006 (Heggem,
Strand, 2010 and Aune-Lundberg, Strand 2010) covering
mainland Norway, issued in 2008 and 2010 respectively.
Through these two datasets Norway has national data for a
European level (minimum mapping unit 25 ha, suitable scale
1:250 000 or smaller) and is a part of one seamless,
homogenous land cover map of Europe based on a standardized
nomenclature with 44 classes.
However, on a national basis, more detailed information is
needed to ensure a sustainable use and management of
Norway's land resources. This requires continuous delivery of
reliable and up-to-date information to decision-makers. Skog og
landskap produces, among others, land cover statistics for the
whole country, all counties and all municipalities.
The statistics are demanded by the government, local authori-
ties, state institutions and private companies. By keeping the
historical statistics, it is easier to observe the increase or de-
crease of the different land cover classes. Especially the agricul-
tural areas are of interest since only approximately 3 % of Nor-
way is arable land. Arable land is usually divided into three sub-
classes: fully cultivated land, surface cultivated land and culti-
vated pastures. Even though the total areca of arable land seems
to be stable among 3 %, the internal distribution within the three
sub-classes is changing. Areas with the best soil quality are de-
creasing and "moving" into the two other classes (Tenge, 2011).
The statistics is based on a database called ARSTAT, which is a
collection of the most detailed information that is relevant and
available. ARSTAT is a map database, but not intended for
cartographic display.
2. DATA SOURCES
2.1 Below the tree line
2.1.1 ARS: ARS is a Norwegian national land capability
classification system and spatial dataset that describes land
recourses, with emphasis on capability for agriculture and
natural plant production. ARS covers the productive part of
Norway (about 60 %). Areas close to, or above the tree line is
not mapped.
This detailed land cover map gives the best information
regarding Norway's land resources below the tree line suitable
use in scales from 1:500 to 1: 20 000. The dataset classifies the
areas based on land cover type, forest site class, tree species and
soil conditions. ARS consists of 104 classes based on
combination of these four attributes. Minimum mapping unit 1$
0.05 ha in agricultural areas and 0.2 ha in outfield. The accuracy
of well-defined boundaries is better than 2 meters.
The field work started in 1960 and was completed in 1995. The
dataset is continuously up-dated: First update was completed in
December 2010. The dataset is periodically revised NS
orthophotos (ground sample distance 10-50 cm) and maintaine
by Skog og landskap (Bjordal and Bjorkelo, 2006).
2.2 Above the tree line
2.2.1 N50: The national digital topographic 1:50 000 map
database N50 is produced and maintained by the i
Mapping Authority (NMA) (Statens kartverk, 20122). NS
contains contour lines, land cover classes, transport, place
names, buildin
land cover clas
forest or arable
000 to 1:100 0
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Some classes 1
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Figure 1. Typi
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