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 n 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. n 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 n single land use type may correspond to a single land cover class e.g. pastoralism to unimproved grassland n single land cover class may support multiple uses e.g. forest used for timber, hunting/gathering, fuelwood, recreation, wildlife preservation, soil protection n 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 n Feature extraction

Information products n Integrated terrain unit

Information products n Land systems

Anderson - Level 1

Anderson - Level 2

Mapping land use n identify target land use categories n define the properties of each land use category in terms of land cover characteristics n specify technique for extracting land cover characteristics using elements of visual image interpretation n apply technique n invert relationship between land cover and land use n generate land use information