Historical oblique aerial photographs as a powerful tool for communicating landscape changes

摘要

This paper reports on a potential new form of data generation and data display to be used for communicating landscape change at local scales, utilizing a huge collection of oblique aerial photographs held by the Royal Library in Copenhagen. The collection contains local scale imagery covering all parts of Denmark recorded between 1930 and 1990 and thus has the potential to illustrate the changes which took place in the rural landscape as a whole after the Second World War, in ways which are suited for use at local scales. Taking into account that landscape change normally happens at a slow rate relative to the perceptive scale of humans, with fine grained changes taking place continuously in local settings, images of this kind present themselves as a way for the general public to become aware of changes which might otherwise be overlooked. To a still more urbanized population where most people do not have an every-day experience with rural landscape change, the images may be a starting point for a renewed engagement with landscapes, not just perceived as a scenery, but rather as a process of interaction with the environment. In order to inform a wider range of people, in competition with other types of information, the imagery provides a point of reference - a single farm or landscape known to the users which people without specific training in landscape research can relate to. The use of a crowdsourcing approach in data generation on a webgis application means that the broader public is both involved in the creation of the data and in the discussion about the changes observed, which become visible when comparing old aerial photographs to the present landscape. In combination with the very local nature of the aerial photographs, this opens up the possibility that the images could serve as a communicational bridge between "abstract" scientific knowledge about landscape change (e.g. change in hedgerow density per year) and the local landscapes where people are living. As such, the approach described in this paper may contribute to the objectives set out in the European landscape convention to facilitate an increased understanding of landscape issues among the public through a democratic learning process. The article concludes, that this approach has a huge potential, although some difficulties exist, relating to the challenge of maintaining a focus on the landscape when using a form of communication which is dialogue-based and relatively unstructured compared to approaches embedded within conventional learning environments. (C) 2014 Elsevier Ltd. All rights reserved.