Fuzzy modelling of acid mine drainage environments using geochemical, ecological and mineralogical indicators

Abstract

Fuzzy logic was applied to model acid mine drainage (AMD) and to obtain a classification index of the environmental impact in a contaminated riverine system. The data set used to develop this fuzzy model (a fuzzy classifier) concerns to an abandoned mine in Northern Portugal-Valdarcas mining site. Here, distinctive drainage environments (spatial patterns) can be observed based on the acid mine drainage formed in the sulphide-rich waste-dumps. Such environments were established, as the effluent flows through the mining area, using several kinds of indicators. These are physical-chemical, ecological and mineralogical parameters, being expressed in a quantitative or qualitative basis. The fuzzy classifier proposed in this paper is a min-max fuzzy inference system, representing the spatial behaviour of those indicators, using the AMD environments as patterns. As they represent different levels (classes) of contamination, the fuzzy classifier can be used as a tool, allowing a more reasonable approach, compared with classical models, to characterize the environmental impact caused by AMD. In a general way it can be applied to other sites where sulphide-rich waste-dumps are promoting the pollution of superficial water through the generation of AMD.

Occurrence, properties and pollution potential of environmental minerals in acid mine drainage

“…This will explain the downstream enrichment in goethite and its predominance at the more distant sampling site (V7). The pH range was extracted from Valente (2004) and Valente and Leal Gomes (2008).…”

A Novel Human Error Probability Assessment Using Fuzzy Modeling

“…This is because the method has been applied in a variety of domains such as geochemical, ecological, and mineralogical indicators in environment science, machine behaviors in computer science, marine safety modeling, port security assessment, etc. ( 10,24,26,27 ) Therefore, the approach has been proven useful for acquiring fuzzy conclusions. The process of the min‐max approach is exhibited in Fig.…”

Application of Fuzzy Logic to Qualify the Environmental Impact in Abandoned Mining Sites

“…For that, there is an AMD numeric index that expresses the contribution of AMD to the environmental impact. It was determined by the model proposed by Valente (2004) and Valente and Leal Gomes (2009a).…”

“…The models based on fuzzy logic are appropriated to deal with the knowledge base that result from the characterization of these complex and heterogeneous systems (Aroba et al 2007;Peche andRodríguez 2009 andValente andLeal Gomes 2009a). Fuzzy logic allows the incorporation of qualitative information, for instance obtained through field observations, which is better described using natural language (Demicco and Klir 2004;Zadeh 1973).…”

“…In the generic field of environmental impact assessment, there are the references of De Siqueira and De Mello (2006), Peche andRodríguez (2009), andShepard (2005). Specifically in mining environments, Aroba et al (2007), Grande et al (2010b), Jiménez et al (2009), andValente andLeal Gomes (2009a) have developed models based on fuzzy logic, able to describe the behavior of watercourses facing mining contamination problems.…”