Avaliação econômico-ambiental do processo de extração de areia dos leitos de rios: uma aplicação do método de valoração contingente.

Abstract

Externalities caused by the activity of sand extraction in river beds have caused serious damage to the environment and society. Mitigating and compensatory actions are necessary so the performance of sand extraction activity would be sustainable. In this context, this research aimed to evaluate the qualitative environmental profile of activities of sand extraction in river beds in order to measure the costs of negative externalities imposed on the environment and society that are not internalized by the agents on the sand market. Specifically, it was sought to: characterize the main externalities occurring in the sand extraction in the bed of the Rio Paraiba; identify the goods substitutes for sand in the production process of the construction industry; Determinate how much society is willing to pay an additional value by cubic meter of sand (CMS) for aggregation of the environmental benefits of the river, through the contingent valuation method (CVM) and Validate the contingent valuation method, checking the degree of accuracy of results in research. The checklist method was used as a way to systematically identify and list the relevant environmental variables, from the environmental impacts observed. After evaluation, it was found 30 negative and four positive results, pointing to the fact that the negative externalities detected overlap relevantly to positive externalities, bringing thus considered technically irreversible damage to the environment and consequent reflections on society. To measure the economic value of natural resource "sand" extracted from the river beds, internalizing costs through price externalities caused to the environment resulting from the commission of such activity, the Contingent Valuation Method (CVM) from the referendum model with monitoring (double logit) was used. From the aggregation of the value found to the CMS of respondents and an annual consumption of sand in Paraíba, one comes to the benefits that the natural resource "sand" can lead to the river itself.