Visual image interpretation
of land use - a GI research
perspective
Dr Nigel Trodd
Coventry 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 class
e.g. pastoralism to unimproved grassland

single land cover class may support multiple
uses
e.g. forest used for timber, hunting/gathering,
fuelwood, recreation, wildlife preservation, soil
protection

single land use may occupy multiple classes
e.g. mixed farming uses cultivated land, improved
pasture, settlements and woodland
Visual image interpretation
tone
texture
shadow
association
shape
pattern
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