Planning the future exploitation of ornamental stones in Portugal using a weighed multi-dimensional approach

Abstract

Portugal is one of the world's leading producers of ornamental stones and, in the last 50 years, this economic sector registered an annual national average growth of 4%. However, the lack of land-use policies that effectively safeguard the access of extractive industry to the places where these resources occur, current and foreseen production is at risk, compromising the contribution of this sector to the national economy and to the supply of forthcoming generations.The multi-dimensional methodology reported in Mateus et al. (2017) was applied to describe the present-day situation, allowing to objectively identify the tracts hosting ornamental stone resources whose access should be safeguarded, therefore avoiding their sterilisation when confronted to other land-use options. A database on the available geological information concerning 65 ornamental stone tracts, covering 0.43% of mainland Portugal, was built. Among the 54 active exploitation centres and 11 potential areas (for which there is no production data), only 21 tracts (0.07% of mainland Portugal) were classified as of “public importance”, meaning they have an intrinsic value that should by itself support a safeguarding decision on their current and future access. According to the weighed criteria used, several promising tracts were not included in this short group. However, these promising tracts do not overcame the threshold due to the shortage of data about regional exploration surveys or on the resource itself, which reflects difficulties in gathering harmonised geological information for all the listed tracts. Thus, two simulation scenarios were completed, corresponding to an increase in knowledge resulting from regional exploration or local, comprehensive geological studies. As a result of these simulated scenarios, the total number of tracts qualified as of “public importance” increased to 41 (0.24% of mainland Portugal). These results highlight the urgent need to supplement the available geological information, contributing to the establishment of a credible and stable mining plan for the Portuguese ornamental stones sector, thus strengthening its sustainability in the short and long term.