Integrating GIS and Remote Sensing in a Dynamic World.

Lately, world climate changes have been producing dramatical effects in both natural and human spaces. Extreme variations on water levels, salinization, floods, desertification, heat and cool waves have been more and more evident. On the other hand, the fast growth of global urbanization, and its consequent dynamic changes over the land surfaces, led to the necessity of seeking, not only where and how these problems occurs, but find the causes and try to develop feasible solutions. Considering this, and particularly for developing countries, integration of Remote Sensing and GIS offers exceptional access to primary natural and artificial data, as well as possibilities for visualization, analysis and monitoring urban growth in a systematic way.
Over the last two decades, there have been in Brazil several initiatives to deal with such situations. It started with deforestation quantification in the Amazon basin as well as monitoring of sugar cane fields and forest burns, all over the country. Later it evolved towards urban flood prevention and, in the last three years, the City of São Paulo has reached the possibility to analyze urban growth, developing a special system dedicated to observe, plan and make decisions on the slums and other forms of informal dwellings. Here, a strong integration of different sources of data, combining high resolution satellite imagery, aerial photographs, cadastral vector maps and socio-economical data, coming from census and the Municipality archives integrates a unique planning, monitoring and assessment tool that can be accessed through the World Wide Web. This paper discusses how this system has been developed and how it contributes to more effective planning and sustainable development