Elaboração de método para definição de áreas de preservação permanente de cursos d’água em áreas urbanas consolidadas

Abstract

Historically, human populations have used rivers by altering their courses, polluting waters, and occupying surrounding areas, which has resulted in the removal of riparian vegetation, an important protector of water bodies. The preservation of these areas has become a socioenvironmental demand and is regulated in Brazil by Federal Law nº 12,651/2012. However, the original text did not provide specific guidelines for Consolidated Urban Areas, a gap partially addressed by Federal Law nº 14,285/2021, which conditions the definition of Permanent Preservation Area (PPA) buffers on the preparation of Socio-environmental Diagnoses (SED). As this topic is recent in the legislative context, there is no established methodology for preparing an SED, particularly for converting its information into effective proposals for riparian PPA buffers. In this context, this study proposes a methodology for the preparation of Socio-environmental Diagnoses, focusing on the application of an expert consultation method. The methodology included the selection of an expert analysis method through a decision matrix, resulting in the adoption of the Delphi Method; the development of a macro-structure for the SED based on literature and current regulations; the definition of criteria for delimiting Consolidated Urban Areas; and expert consultation through questionnaires. The expert consultation was conducted in two rounds, whose results were analyzed using measures of central tendency and dispersion, allowing the assessment of the level of consensus achieved. The results of the SED and the expert consultation were integrated through multiple criteria, and the proposed methodological procedures were applied in a municipality in the Serra Gaúcha region. The results indicate that a satisfactory level of consensus was achieved between the Delphi rounds and demonstrate the practical feasibility of the proposed procedure, validated by its application in the municipality of Garibaldi. It is concluded that the developed methodology contributes to reducing the gap between legal norms and their application in urban territorial planning, constituting a technical instrument capable of supporting the definition of PPA buffers in Consolidated Urban Areas. [resumo fornecido pelo autor]