Land use or land cover?

Today most land cover data include elements of land use and vice versa. Historically, mappings of land were concerned with land use and manually recorded socio-economic activities and land management practices. With the increased availability of remotely sensed imagery since the 1970s and the ability to process such data using computers, the principal concern of such mappings has been to record the phenomenon of land cover and land use. As Veldkamp and Verburg (2004) note, many land use and/or land cover modelling approaches have often treated land use and land cover as if they were interchangeable concepts. However, the conflation of the two concepts in most geographical information derived from remotely sensed data is problematic for the research community who require either land cover for environmental models or land use for policy making. This special issue of the Journal of Land Use Science contains four papers describing issues related to land use and land cover. Each of them tackles a different aspect of the land cover/land use paradigm. Comber (this issue) presents a philosophical rationale for the separation of land use and land cover. He argues that their frequent confusion is problematic for many data integration and modelling activities which require either ‘land use’ or ‘land cover’ as their inputs. For example, the common approach to overcome this confusion is to translate land cover classes to land use classes. However, Comber notes that the direct translation of cover to use is not straightforward due to their different temporal attributes: land cover tends to be static over short periods of time, whereas there may be multiple land uses at any given place. The paper proposes an approach for the separation of land cover and land use using ‘data primitives’ – dimensions that describe at the most fundamental level the land use and land cover processes. The method presented by Comber identifies different aspects of land use and land cover, for example the economic value and social value in urban contexts and food production in rural areas. Each class is scored in each dimension, and by combining the scores the degree of land cover or land use is (subjectively) determined. The method allows the concepts of land cover and land use to be separated relative to the task in hand, and the outputs show the degree of land use, the degree of land cover and the locations where the concepts of use and cover are confused. Bakker and Veldkamp (this volume) propose the land use–land cover ratio as a method for characterising different landscapes. They also question the assumption of a one-to-one ratio between land use and land cover found in many modelling activities as multiple uses can be related to one cover type. Much of the mismatch between land use and land cover can be attributed to differences between the total land area dedicated to the production or provision of a land-based commodity (observed land cover) and the actually used or harvested area (reported as land use). Bakker and Veldkamp introduce the concepts of ‘primary land uses’ as the production or provision Journal of Land Use Science Vol. 3, No. 4, December 2008, 199–201