MAPPING URBAN TRANSFORMATIONS USING SATELLITE IMAGES
A. Bianchin, L. Bravin
Planning Department University Iuav of Venice
alberta@iuav.it
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.