Visual image interpretation of land use - a GI research perspective
Dr Nigel TroddCoventry University
Land use human employment of the land
‘Almost all of the world’s lands are now used and managed’ (Richards 1990).
‘Human actions rather than natural forces are the source of most contemporary change in the states and flows of the biosphere. Understanding these actions and the social forces that drive them is thus of crucial importance for understanding, modeling and predicting global environmental change and for managing and responding to such change’ (Turner & Meyer, 1994).
Land use - data sources
‘Land use maps have been completed for many specific areas of the world. These efforts were based on various data sources and are not generally compatible with each other. A consistent, hierarchical classification system is ... to be encouraged’ (WMO 1997).
An ‘objective system that can be updated annually may be possible using remote-sensing of land cover change (perhaps combined with agriculture and forestry production statistics, socio-economic spatial data such as population and transportation). Landsat (TM) is one of the most appropriate data streams for land use monitoring. While it is still a research topic on how to use this data to produce a land use product, it is important that this data stream continues to be archived and kept accessible’ (WMO 1997).
Land use - research agenda
What information is needed?Frequency of measurement: Once every 5 years.
Spatial resolution: 5 m - 1 km depending on the spatial heterogeneity of land use; at least 30 m for many regions.
Accuracy/precision required: TBD.
What R T D is needed? Develop regionally-specific relationships between land cover
and land use;
Define the lowest acceptable spatial resolution;
Develop reliable procedures of inferring land use from land cover, on a regional basis.
Land use / land cover physical state of the land
single land use type may correspond to a single land cover classe.g. pastoralism to unimproved grassland
single land cover class may support multiple usese.g. forest used for timber, hunting/gathering,
fuelwood, recreation, wildlife preservation, soil protection
single land use may occupy multiple classese.g. mixed farming uses cultivated land, improved
pasture, settlements and woodland
Visual image interpretation
tone
texture
shadow
associati
on
shapepattern
size
site
Information products
Feature extraction
Information products
Integrated terrain unit
Information products
Land systems
Anderson - Level 1
1 Urban or built-up land
2 Agricultural land
3 Rangeland
4 Forest land
5 Water
6 Wetland
7 Barren land
8 Tundra
9 Perennial snow or ice
Anderson - Level 2
1 Urban or built-up land
11 Residential
12 Commercial & services
13 Industrial
14 Transportation, comms & utilities
15 Industrial & commercial complexes
16 Mixed urban or built-up land
17 Other urban or built-up land
Anderson - Level 2
2 Agricultural land
21 Cropland & pasture
22 Orchards, vineyards etc.
23 Confined feeding operations
24 Other agricultural land
Mapping land use
identify target land use categories define the properties of each land use
category in terms of land cover characteristics specify technique for extracting land cover
characteristics using elements of visual image interpretation
apply technique invert relationship between land cover and
land use generate land use information