Application of very high-resolution satellite imagery for vulnerability assessment in mega cities: A case study in Delhi/India

The 21st century is the century of the cities and of urbanization. Mega cities in rapidly urbanizing regions are hot spots of demographic and socio-economic dynamics. Their rapid growth results in uncontrolled processes of fragmentation. Due to the high dynamics of mega cities, the traditional methods such as statistical analyses or fieldwork are limited to capture the urban process. Remote sensing provides the opportunity to monitor spatial patterns of urban structures with high spatial and temporal resolution. VHR remote sensing data from the QuickBird sensor are used to identify urban structures and dynamics within Delhi/India. The paper presents a first semi- automated, object-based classification approach which allows the distinction of different settlement types within the urban area. Thereby the research is focused on the identification of "informal settlements". In order to find out whether VHR remote sensing data can provide indicators to identify socio-economic structures and dynamics, the classification results were embedded in an analysis concept. By combining remote sensing derived data with questionnaire information, it is possible to calculate specific population and water related parameters. This is understood to be a first step to the development of indicators which will help to identify and understand the different forms, actors and processes of vulnerability in mega cities.