Multiple data available to analyze the urbanization phenomenon in temporal and spatial scales.
ISBN 978-85-88783-11-9
Authors
1Moura de Lacerda Teixeira, V.
1UNIVERSITÉ JEAN MOULIN LYON 3 Email: vanessamlt2@gmail.com
Abstract
The purpose of this work is to analyze the dynamics of the land use to understand the reduction of natural and anthropic natural areas through urbanization for 60 years in the Lakes Region of Rio de Janeiro State, Brazil. It focuses on spatial analysis to generate hypotheses that determine the choices for localization of the residential lot subdivisions and then decide whether to promote or not, the urbanization around them. Two processes of the phenomena are in question: urban sprawl and densification. They lead to consumption of natural and anthropic natural areas at the regional scale, passing through the municipal ones. Finally, the urban scale, with the most concrete example of Araruama city, will be analyzed as well to present the characteristics, in terms of density, of some residential lot subdivisions. These processes highlight the sustainability of the natural and anthropic natural areas in a region where the single-family housing for a temporary use (or secondary residences) is predominant. For centuries, natural resources are exploited for human consumption. However their reduction is due to the space production in different dimensions: economic, social and cultural. The comprehension of these processes was possible with the land occupation maps through four years – 1969, 1986, 1998 and 2010. Their analysis was comparative in terms of consumption of space around urban areas. It reveals that the urban area is particularly concentrated in the coastline around the lagoon: the management of the territory has enriched the front of it by putting back the development of peripheral areas. Linear development along the lagoon is the result of space production, which began in the 17th century, with the arrival of Europeans. Amaral Peixoto highway in the 1950s represented the framework guiding this development on different periods of its construction. The construction of the bridge Rio-Niterói, in the 1970s, has reinforced the development of the region. Based on the maps, we verify that this significant urban growth has affected natural and anthropic natural areas like wetlands, salt marshes, agricultural and forests areas. It also confirms a substantial urban occupation on the dunes and on the restinga, mainly after 1986. Between 1969 and 1998, about 30% of urbanized areas have also consumed the herbaceous vegetation, which have been modified by population or merely abandoned. Some of these areas were forests. These herbaceous vegetation areas comprise favorable surfaces for the urban development in reason to the absence of legislation and no effective utilization for agricultural production or other uses. The main discussion is about the use of the cartography to represent the phenomena of urbanization through a period of 60 years. The available sources to compose this representation were from various institutions, which made it difficult to calculate accurately the reduction of natural and anthropic natural areas. So the question is: How to use multiple data available to analyze the urbanization phenomenon in temporal and spatial scales? The major challenge of this work was to organize both the data spatially and historically. However, the lack of data that corresponds to the time and space analysis, made it necessary to use some data initially considered less relevant, such as satellite imagery, which increased processing time. The applicability of data collected in a GIS has been very important, due to the possibility of its reuse for other periods and other data format (e.g. actualization of orthophotos). The understanding of urban sprawl and the densification phenomena was possible through spatial and historical comparisons. The grouping of data in a unique format (for use in a GIS context) allows linking the spatial and temporal aspects in order to highlight the urban processes and its responsibilities on natural and anthropic natural areas reduction.