Classificação de dunas em áreas urbanas a partir do valor de relevância de suas funções ambientais - estudo empírico em Natal/RN

Abstract

Environmental functions are directly related to quality of life and social welfare, especially in urban areas, where they are even more important due to the wide variety of environmental (pollution and degradation) and social (segregation and inequality) stressors present in these spaces. In the city of Natal, experimentation area, the dunes are the most representative landscape element, features that perform a series of environmental functions with outstanding importance for society. Despite the recognition of the importance of the dunes, there is a conflict between use / occupation and preservation, resulting in recurrent cases of degradation due to urban expansion over a site with wide distribution of these geomorphological features. The present work defends the hypothesis that the environmental functions performed by the dunes can be qualified, quantified and hierarchized in order to guide and discipline the decision making about the permitted and appropriate types of uses and occupations for these environments. The objective was to propose an integrative methodology for the practical application of the concept of environmental functions and for the characterization of dune conservation status (SCD), useful for planning, management and decision-making, using 57 dunes for analysis and experimentation not located in environmental protection zones of the city of Natal / RN, encompassing the 53 dunes identified in CONPLAM Resolution nº 001/2018 and four others located on the border with the Ocean. A presentation and discussion of various terms and concepts associated with this theme (ecosystem services, landscape functions, geosystem services, etc.) was presented and the term environmental functions was chosen as the most appropriate to the proposed objectives. The study identified 25 environmental functions associated with dunes and 55 experts from 19 countries participated in the definition of the relevance value of these functions (VRFA). The largest VRFA were identified in the dunes at the edge of the ocean, due to the functions associated with coastal protection and saline wedge protection. The SCD was based on qualitative criteria such as area, morphological transformation, vegetation cover and scenic visibility. The obtained results pointed to a relation between the conservation status of the dunes and the number of functions, since the highest amounts were found in dunes with medium and high conservation status. The methodology proved to be valid for the dunes of the city of Natal, since it managed to distribute the dunes in a grading gradient, considering the VRFA as a useful indicator for decision-making.