Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Fuzzy Land Cover/Land Use Ontologies
Ola Ahlqvist, PhD
Department of Geography
The Ohio State University
ahlqvist.1@osu.edu
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Land use and land cover data
• Importance
– climate modeling, urban planning, landscape change
assessment, hydrological models, and unknown future
issues
– Demand that data can be re-purposed for a variety of end
uses
• Initiatives
– Standards: National Vegetation Classification Standard
(Vegetation Subcommittee, 1997), the Nordic Landscape
Monitoring Project (Groom, 2005), the CORINE Land Cover
(CEC, 1995 and 1999; Bossard et al., 2000), the standard
classification for land cover of South Africa (Thompson,
1996), GLC2000 (Bartholomé and Belward, 2005) ,
UNEP/FAO Land Cover Classification System (LCCS) (Di
Gregorio and Jansen, 2000)
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
A traditional land cover taxonomy
• Easily translated to an ontology description language as classsubclass relations and class specific properties
• But no agreement on a unified taxonomy
– CORINE
– GlobCover
– MODIS/IGBP
• Not even our own USGS system could stay the same from
one time to the other
– National Land Cover Data (NLCD) used slightly different
classes in 1992 and 2001
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
National Land Cover Data (NLCD) change example
Land Cover
Chester County, PA
2001
Land Cover
Chester County, PA
1992
t
t
0
5
10
15
20
0
Kilometers
Different classification
systems create
problems!
5
10
15
20
Kilometers
11 Open Water
21 Low Intensity Residential
22 High Intensity Residential
23 Commercial/Industrial/Transport.
32 Quarries/Strip Mines/Gravel Pits
33 Transitional
41 Deciduous Forest
42 Evergreen Forest
43 Mixed Forest
81 Pasture/Hay
82 Row Crops
85 Urban/Recreational Grasses
91 Woody Wetlands
92 Emergent Herbaceous Wetlands
?
?
11 Open Water
21 Developed, Open Space
22 Developed, Low Intensity
23 Developed, Medium Intensity
24 Developed, High Intensity
31 Barren Land (Rock/Sand/Clay)
41 Deciduous Forest
42 Evergreen Forest
43 Mixed Forest
81 Pasture/Hay
82 Cultivated Crops
90 Woody Wetlands
95 Emergent Herbaceous Wetlands
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Same issues around global definitions of “forest”
16
Zimbabwe
14
Tree height (m)
12
Sudan
10
Turkey
Tanzania
8
6
United
States
4
UNESCO
China
Jamaica
2
Estonia
0
0
20
40
60
Canopy cover (%)
80
100
after Lund (2006) and Comber et al. (2006)
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Solutions?
• The FAO and UNEP Land Cover Classification System (LCCS)
– multi-purpose classification system
– capable of comparing land cover types across taxonomies
– uses diagnostic criteria rather than pre-defined classes
• Now at v.3 - Land Cover Meta Language (LCML)
– a predefined set of land cover basic objects are enriched on
their semantic significance with external qualities and
attributes
– Use of UML and XML for formal description of an ontology
– http://www.glcn.org/ont_2_en.jsp
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Example formalization of land
cover definitions
CORINE Land Cover
Class Name
Corine
Code LCCS classifiers
LCCS Code
Broadleaved forest
3.1.1. Major land cover class: Natural and Semi-Natural Terrestrial Vegetation (A12)
Life form :
Trees (A3)
Cover:
Closed, > (70-60)% (A10), (70-60)%-40% (A12)
Height:
>30 – 3 m (B2)
Leaf Type:
Broadleaved (D1)
Leaf Phenology:
Deciduous (E2)
20090 /
20132-1
Peatbogs
4.1.2. Major land cover class: Natural and Semi-Natural Aquatic Or Regularly Flooded
Vegetation (A24)
Life form :
Herbaceous (A2)
Cover:
Closed > (70-60)%
Height:
>3 – 0.03 m (B4)
Water seasonality:
On waterlogged soil (C3)
40057 /
40985-R1 /
6005-M251
Major land cover class: Natural and Semi-Natural Aquatic Or Regularly Flooded
Vegetation (A24)
Life form :
Lichens/Mosses (A7)
Cover:
Open (70-60)-(20-10)%
Water quality:
Fresh
Major land cover class: Bare Areas (B16)
Surface aspect:
Bare soil a/o Other
Lithology:
Organic rock - Peat
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Parameterization using FAO’s Land Cover Classification System v.2
A16 1-4 %
A13 15-40%
A10 > 65%
A15 4-15 %
16
LCCS
Classifiers
A12 40-65%
Zimbabw e
14
Tanzania
Morocco
6
United
States
4
Mexico
2
Netherlands
Ethiopia
UNESCO Virgin Islands
China Cambodia
South Africa
Jamaica
Kyrgyzstan
Kenya
B5 > 14 m
Mozambique
B6 7-14 m
Turkey
8
B7 3-7 m
B2 > 3 m
Sudan
10
B1 2-7 m
Tree height (m)
12
Estonia
0
0
20
40
60
80
100
Canopy cover (%)
• Unnecessarily crude where detail is actually available
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
With v.3 - Land Cover Meta Language (LCML)
U.S. NLCD 1992 Low Intensity Residential
Domain
Scale
Range
waterCov.owl
Ratio
[0
waterPhase.owl
10
20
30
40
50
60
70
80
90
100]
Nominal {Ice, Water}
imperviousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
vegetationCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
development.owl
Nominal {Residental, Commercial, Mining}
surfaceType.owl
Nominal {Earthen material, Constructed}
treeCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
treeHeight.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
deciduousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
evergreenPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
shrubCoverPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
60
70
80
90
100]
woodyTenure.owl
Nominal {(Semi)Natural, Cultivated/Planted}
grassHerbTenure.owl
Nominal {(Semi)Natural, Cultivated/Planted}
grassHerbCoverPct.owl
Ratio
[0
10
20
30
40
50
crop.owl
Nominal {RowCrops, SmallGrains, Fallow, Hay, Grass}
waterPersistence.owl
Nominal {Permanent, Periodically, Waterlogged}
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Attributes values allow for evaluation of category semantics
Distance
• Two metrics of semantic relations
– Distance
Woodland (USDA F.S., 1997)
– Overlap
Woodland (Hyytiäinen, 1995)
Overlap
0
U.S. NLCD 1992 Low Intensity Residential
Domain
Scale
Range
waterCov.owl
Ratio
[0
waterPhase.owl
10
20
30
40
50
60
70
80
90
100]
Nominal {Ice, Water}
20
40
60
Canopy cover (%)
80
100
U.S. NLCD 2001 Developed, Low Intensity
Domain
Scale
Range
waterCov.owl
Ratio
[0
waterPhase.owl
10
20
30
40
50
60
70
80
90
100]
Nominal {Ice, Water}
imperviousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
imperviousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
vegetationCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
vegetationCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
development.owl
Nominal {Residental, Commercial, Mining}
development.owl
Nominal {Residental, Commercial, Mining}
surfaceType.owl
Nominal {Earthen material, Constructed}
surfaceType.owl
Nominal {Earthen material, Constructed}
treeCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
treeCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
treeHeight.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
treeHeight.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
deciduousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
deciduousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
evergreenPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
evergreenPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Attributes values allow for evaluation of category semantics
Distance
• Two metrics of semantic relations
– Distance
Woodland (USDA F.S., 1997)
– Overlap
Woodland (Hyytiäinen, 1995)
Overlap
• Bivariate color scheme
– Different types of change
20
40
60
Canopy cover (%)
Similar
but Disjoint
classes
80
Very
different
classes
Overlap-1
0
Very
similar
classes
Distance
Class/
subclass
relationship
100
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
But land cover/use concepts are rarely clear cut…
• Fuzzy set theory and fuzzy numbers allow for vagueness
“Closed Tree Cover”
“Open Shrub Cover”
“Sparse vegetation”
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
…and they typcially have many attribute dimensions
U.S. NLCD 1992 Low Intensity Residential
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Domain
Scale Range
waterCov.owl
Ratio
waterPhase.owl
[0
10
Domain
20
30
40
50
60
70
80
90
100]
Nominal {Ice, Water}
imperviousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
vegetationCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
development.owl
Nominal {Residental, Commercial, Mining}
surfaceType.owl
Nominal {Earthen material, Constructed}
treeCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
treeHeight.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
deciduousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
evergreenPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
shrubCoverPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
woodyTenure.owl
Nominal {(Semi)Natural, Cultivated/Planted}
grassHerbTenure.owl
Nominal {(Semi)Natural, Cultivated/Planted}
grassHerbCoverPct.owl
crop.owl
waterPersistence.owl
Ratio
[0
10
U.S. NLCD 2001 Developed, Low Intensity
20
30
40
50
60
70
Nominal {RowCrops, SmallGrains, Fallow, Hay, Grass}
Nominal {Permanent, Periodically, Waterlogged}
Comparison in 16D can
be summarized
80
90
100]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
waterCov.owl
waterPhase.owl
Scale
Range
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
Nominal {Ice, Water}
imperviousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
vegetationCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
development.owl
Nominal {Residental, Commercial, Mining}
surfaceType.owl
Nominal {Earthen material, Constructed}
treeCov.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
treeHeight.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
deciduousPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
evergreenPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
shrubCoverPct.owl
Ratio
[0
10
20
30
40
50
60
70
80
90
100]
50
60
70
80
90
100]
woodyTenure.owl
Nominal {(Semi)Natural, Cultivated/Planted}
grassHerbTenure.owl
Nominal {(Semi)Natural, Cultivated/Planted}
grassHerbCoverPct.owl
Ratio
[0
10
20
30
40
crop.owl
Nominal {RowCrops, SmallGrains, Fallow, Hay, Grass}
waterPersistence.owl
Nominal {Permanent, Periodically, Waterlogged}
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
1992
/85
1992
/91
1992
/92
Wetlands
1992
/82
Herbaceous
1992
/81
Emergent
Woody Wetlands
Grasses
1992
/43
Urban/ Recreational
1992
/42
Row Crops
1992
/41
Pasture/Hay
1992
/33
Mixed Forest
Evergreen Forest
Deciduous Forest
1992
/32
Transitional
1992
/23
Mines/ Gravel Pits
Quarries/ Strip
Transportation
Industrial/
1992
/22
Commercial/
residential
1992
/21
High intensity
residential
1992
/11
Low intensity
Open Water
1992
Semantic relations summarized in matrix form
Open water
5.6
0
0
0.4
0.1
0
0.5
0.2
0.1
0.4
0.1
0
0
0
Developed, Open
Space
0.3
51.6
0.8
4.8
0.3
0.5
19.9
4
10.5
32.0
5.3
2.8
0
0.2
Developed, Low
Intensity
0.3
23.5
1.6
6.8
0.6
1.3
12.1
2.1
3.6
21.3
5.6
0.1
0
0.3
Developed, Med.
Intensity
0.3
9.3
1.7
9.4
1.3
1.1
3.5
0.4
0.5
5.9
2.7
0
0
0.2
Developed, High
Intensity
0.1
1.9
0.6
4.7
0.7
0.4
0.5
0
0.1
0.9
0.7
0
0
0
Barren Land
(Rock/Sand/ Clay)
0.1
2.8
0
0.3
0.3
0.3
7.8
1.7
2.1
4.1
0.8
0
0
0.1
Deciduous Forest
1.2
10.5
0.1
1.4
0.1
0.8
408.7
8.2
22.6
73.9
3.8
0
2.4
1.3
Evergreen Forest
0.1
1.4
0
0.1
0
0
7.3
4.8
3
2.8
0.1
0
0
0.1
Mixed
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Hay
1.1
19.4
0.3
2.0
0.1
12.8
114.5
26.2
40.8
476.3
54.1
0.5
0.8
1.3
Cultivated Crops
0.6
6.7
0.2
2.4
0.4
2.3
73.5
5.5
10.7
169.3
59.6
0.1
0.6
1.1
Woody Wetlands
1.2
1.6
0
0.6
0.1
0.1
19.9
1.4
1.3
5.2
0.6
0
1.7
0.7
Emergent
Herbaceous
Wetlands
0.8
0.4
0
0.4
0.1
0
2.6
0.4
0.3
2.2
0.6
0
0
0.3
Pasture/
Forest
Overlap-1
2001
Dissemblance
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Quarries/Strip
Mines/Gravel Pits
Barren Land
(Rock/Sand/Clay)
Perennial Ice/ Snow
Fallow
Bare Rock/
Sand/Clay
Open Water
… with the semantic similarity
metrics we can compare within
and across conceptual spaces
Commercial/
Industrial/ Transportation
Transitional
Shrubland
Shrub/Scrub
Developed, High
Intensity
Orchards/
Vineyards/
Other
Developed, Medium
Intensity
Developed,
Low Intensity
Evergreen
Forest
Developed,
Open Space
Mixed
Forest
Woody Wetlands
High Intensity
Residential
Low Intensity
Residential
Deciduous
Forest
Emergent
Herbaceous
Wetlands
Grasslands/
Herbaceous
Urban/
Recreational
Grasses
Pasture/Hay
Cultivated
Crops
Row Crops
Small Grains
Pasture/Hay
National Land Cover Data
MDS of class definitions
1992 2001
Water
Developed
Barren
Vegetated (Forest)
Shrub land
Non-natural woody
Grasslands
Herbaceous planted
Wetlands
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Semantic change image
•
•
•
Summarize landscape change
from a cognitive perspective
An overall, spatially explicit
evaluation of land cover change
throughout the study area
Nuanced assessments of
graded changes even for
heterogeneous, nominal land
cover types
Fuzzy Land Cover/Land Use Ontologies – GeoVoCamp 2011
Ola Ahlqvist, Department of Geography
Some references
Ahlqvist, O., 2004, A parameterized representation of uncertain conceptual spaces,
Transactions in GIS, 8(4), 493-514.
Ahlqvist, O., 2008, Extending post classification change detection using semantic
similarity metrics to overcome class heterogeneity: a study of 1992 and 2001
National land Cover Database changes, Remote Sensing of Environment,
112(3):1226-1241
Comber, A., Fisher, P., and Wadsworth, R., 2006, What is land cover?, Environment and
Planning B, 32: 199-209
Gärdenfors, 2000, Conceptual Spaces: The geometry of thought, MIT press.
Kaufman A and Gupta M M, 1985, Introduction to fuzzy arithmetic. New York, Van
Nostrand Reinhold Company
Lund, H.; Gyde (coord.) 2006. Definitions of Forest, Deforestation, Afforestation, and
Reforestation. [Online] Gainesville, VA: Forest Information Services.
http://home.comcast.net/~gyde/DEFpaper.htm.
Global Land Cover Network (GLCN) - http://www.glcn.org/index_en.jsp
- Land cover Ontology - http://www.glcn.org/ont_0_en.jsp
- ISO standard - Part 1 & 2
http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=32562
http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=44342
U.S. National Land Cover Database - http://www.mrlc.gov/