Monitoring urban sprawl from historical aerial photographs and satellite imagery using texture analysis and mathematical morphology approaches

Abstract

In the last few decades, Urban sprawl refers to the outgrowth of urban areas caused by uncontrolled,uncoordinated and unplanned growth. The rapidity of urban dynamics has a significant impact on the spatial patterns associated with the growth and expansion of metropolitan areas. Spain has been urbanizing large amounts of land, while the total population has hardly increased. Much of the expansion of (sub) urban development has come at the expense of farmland, forest land, and other areas of open space, mostly as the result of low-density, sprawling development. Sound land use planning and open space preservation are important issues in Spain, but currently very little quantitative information is available describing urban sprawl and land use change. Black and white aerial photography from 1956 and panchromatic satellite imagery from 2005 are used for studies of growth and change of informal settlements in various landscapes in Spain. The digital data is Ortho-rectified, corrected for brightness variations and mosaicked using ER Mapper and Global Mapper software. The texture analysis and mathematical morphology are applied with ENVI and MATLAB. The focus of this study is to evaluate the capability of using textural analysis for mapping the compact urban areas of Barcelona city in Spain. The significance of this study is due to (1) the use of historical aerial photographs and SPOT imagery for monitoring urban land use change; and (2) the research being on developing Spain cities, which have rapidity of urban dynamics.