Remote Sensing applied to the Impact Assessment of Rainwater Storage in the Urban Drainage System

Abstract

The urbanization process, with an increase in the number of constructions, results in the waterproofing of surfaces, reducing infiltration and underground runoff, and a consequent increase in surface runoff. In this context, researchers are looking for technologies to minimize such environmental problems, aiming to improve not only the current situation, but also the next generations. Thus, green technologies are included to mitigate environmental problems, with an emphasis on green roofs. Such a scenario of urban growth and environmental problems is evidenced in large urban centers, such as the municipality of Recife-PE, specifically in the Administrative Political Region RPA2, in the neighborhood of Dois Unidos. To identify green and urbanized areas, Remote Sensing technology was used with the use of the Normalized Difference Construction Index (NDBI) and, to identify the low points of the roads and perform the flood analysis, the Digital Elevation Model was used (MDE) with the generation of contour lines. The results indicated that the two actions investigated, green roofs and water tanks, together, were inefficient in resolving the floods and that the costs of adapting the roofs for the implementation of green roofs were more expensive than the purchase of water tanks from 500 L. On the other hand, such actions can contribute to reducing the dimensions of the urban drainage project by reducing the volume of excess rainwater (above the drainage capacity of the gutter) by about 45% (from 46,033.30 m3 to 20,902.23 m3).