MAPPING URBAN TRANSFORMATIONS USING SATELLITE IMAGES
A. Bianchin, L. Bravin
Planning Department University Iuav of Venice
The qualitative and quantitative analysis of urban transformation within a large area can be performed using satellite imaging. This paper analyses changes on the urbanization process occurred over a period of ten years (1990-2000) in a vast area located in the Veneto Region (north-eastern Italy). These studies aimed to confirm through quantitative data a supposed trend towards a diffusion of urbanization in the region (e.g. the diffuse city phenomena).
A simple comparison between two maps of built-up space at two dates lacks information about the characteristics of the urban development: be it concentrated or diffuse. For such purposes the description of urban phenomena needs to differentiate different typologies.
The methodology developed, comprises two separate successive phases. The first phase involves the creation of a map of built-up areas on the two specified dates; the second, focuses on the identification and definition of classes or typologies of built-up areas pinpointed in the first phase. Change analysis is therefore carried out by comparing the types of built-up areas.
The strategies, approaches, and processing techniques that may be used in the first phase are discussed and methodological considerations made.
Processing techniques of the second phase, which includes computing local density of built-up areas, morphological segmentation and landscape indices, are presented and discussed in the context of the Veneto region, and later on, considerations are made on the significance that the results of this processing take on in different spatial scales.