Urban rivers and the free path of water

The challenge of applying Permanent Preservation Areas in consolidated urban areas

Abstract

Objective – To conduct a critical analysis, through a bibliographic survey and geoprocessing mapping, of changes in environmental policies for the “protection” of urban rivers, more specifically Federal Law No. 14,285, of December 29, 2021, which applies to Permanent Preservation Areas (PPA) in consolidated urban areas. The case study is the Piabanha River, in the municipality of Petrópolis (RJ), on the occasion of the disaster caused by the rains in February 2022.

Methodology – Bibliographic survey and geoprocessing analysis of two stretches of the Piabanha River. The maps were produced using the Quantum Gis program (QGis 3.28). In the final analysis, buffers were created, representing the limit of 30 and 50 meters, according to the Forest Code legislation, considering that the width of the river varies between 10 and 20 meters.

Originality/Relevance – The themes of urban rivers and PPA converge on the problems in urban areas, on people's lives and the impact on the environment. With extreme events occurring with increasing frequency and intensity, it is increasingly important to observe and identify urban planning problems that are intensified by disasters caused by heavy rains.

Results – Most of the areas most affected by the disaster are located within the PPA strip (30/50 meters on each bank of the watercourses), emphasizing the urgency and importance of preserving this strip, leaving it free of constructions and other human interferences that could interrupt the free flow of water.

Theoretical/Methodological Contributions – Geoprocessing analysis is an important tool for observing urban land use and identifying flaws in urban and environmental protection policies.

Social and Environmental Contributions – The results showed high vulnerability with regard to occupations on the banks of the rivers analyzed, both of a social nature, representing the risk of loss of lives, and of an environmental nature, as urban rivers are completely neglected in laws and actions aimed at urban and environmental policies