Air photo interpretation for the measurement of changes in urban land use

This research is concerned with the use of aerial photographs for the measurement and recording of urban land use. A suitable land use classification scheme and a methodology for the measurement and recording of land use areas are developed. Use is made of these to obtain data for geographical research and as basic information for town planning. - A land use classification scheme suited to the requirements of geographical research, and compatible with the limitations of the air photograph as a data source, is formulated and tested for interpretational accuracy. Methods for the measurement and recording of land areas are discussed, and as a result grid systems are considered to be most suited to the requirements of the project. Tests are carried out to assess the characteristics of line grids and of dot grids used on maps and on aerial photographs. Experimental evidence indicates that the optimum system, balancing accuracy with practicability and economy, involves the use of orthogonal dot grids as overlays to the aerial photographs. The system is used over a seventy square kilometre area in and around Preston, Lancashire, to produce areal data of land use for the years 1946 and 1973. Computer programs are used to derive tabular data of land use, land use change matrices, and a range of computer maps. The results are used in an analysis of the changes in land use, and the relationship between land use and population over the period. The analysis indicates that, within the limits of the data, relationships exist between rates of change of land use and of population, whereas actual land use and population, at the two dates, appear both to be related to location (within the urban area) rather than to each other. The conclusion drawn from the research is that this method of measurement of changes in urban land use by means of aerial photography produces areal data of an accuracy, and in such a form, as to be suited to the purposes specified.