The unbearable fuzziness of being sustainable: an integrated, fuzzy logic-based aquifer health index

Abstract

We introduce a groundwater sustainability index offering a novel combination of features. It is holistic in the sense that it incorporates both water quantity and water quality indicators. The former employs the signalto-noise ratio of long-term trends estimated via robust regression; the latter uses concentration of the primary contaminant of concern. A fuzzy inference system integrates these unlike metrics. The system also explicitly encodes expert knowledge and stakeholder values, and directly acknowledges subjectivity in environmental condition "grading," through the use of linguistic rules and fuzzy sets, respectively. The fuzzy rule base is constructed such that poor environmental conditions captured by one measure are not hidden by good performance in another. A standard Mamdani (max-min) inference engine is used with centroid defuzzification. The outcome is an intuitively accessible index ranging from 0 to 100. The method is demonstrated using examples from the Abbotsford-Sumas aquifer, an important and managerially challenging transboundary (Canada-US) water resource.Key words environmental index; groundwater; applied fuzzy logic; water resource management; hydrogeology; transboundary L'insupportable flou de la durabilité : un indice intégré de la santé d'un aquifère basé sur la logique floue Résumé Nous présentons un indice de durabilité des eaux souterraines offrant une combinaison inédite de caractéristiques. Il est holistique dans le sens où il incorpore à la fois des indicateurs de quantité et de qualité de l'eau. Le premier indicateur emploie le rapport signal -bruit de tendances à long terme estimé par une régression robuste ; le second utilise la concentration du principal polluant incriminé. Un système d'inférence floue intègre ces différentes métriques. Le système code également explicitement les connaissances d'experts et les valeurs des intervenants et reconnaît directement la subjectivité de la classification de l'état de l'environnement par l'utilisation respective de règles linguistiques et d'ensembles flous. La base de règles floues est construite de telle sorte que de médiocres conditions environnementales indiquées par une mesure ne soient pas cachées par la bonne performance d'une autre. Un moteur d'inférence de Mamdani (max-min) standard a été utilisé avec concrétisation centroïde. Le résultat est un index intuitivement accessible allant de 0 à 100. La méthode est illustrée par des exemples de l'aquifère d'Abbotsford-Sumas, une importante ressource en eau transfrontière (Canada-États-Unis) dont la gestion est délicate.Mots clefs indice environnemental ; eaux souterraines ; application de la logique floue ; gestion des ressources en eau ; hydrogéologie ; aquifère transfrontalier

Using Envision to Assess the Sustainability of Groundwater Infrastructure: A Case Study of the Twin Oaks Aquifer Storage and Recovery Project

“…If Envision were used in conjunction with a groundwater specific sustainability index (such as [4,[10][11][12][13]), both the water system and the individual water project could be reviewed together in a truly holistic manner. A combination of both types of indices would provide the most integrated and thorough view of sustainability in groundwater.…”

“…Sandoval-Solis et al [9] have developed a water sustainability index based on management policies and mostly focus on technical aspects of sustainability; however, no environmental, social, or economic criteria are included [10]. In groundwater, different methods have been used to overcome the challenges associated with creating a water sustainability index and have included: analytic hierarchy processes in conjunction with information entropy theories [11], fuzzy logic [12], groundwater footprints [4], and an unweighted composite index [13].…”

Groundwater quality assessment with respect to fuzzy water quality index (FWQI): an application of expert systems in environmental monitoring

“…Based on the driven results from WQI and its developed fuzzy index, similar performance was observed in most of the cases. As Fleming et al (2014) explained, a major advantage of a fuzzy logic approach for constructing of environmental indices, relative to conventional approaches based on weighted averages, is that the rules of a fuzzy expert system can be built such that good quality in one parameter does not hide bad quality in another. In the present paper, in Table 7 the similar philosophy has been adopted.…”

Estimation of the volume of production of turbine vapor of a fuel boiler with stochastic exogenous factors

“…Article [8] presents the groundwater stability index, which offers a new combination of characteristics in which the signal-to-noise ratio of long-term trends is used, estimated using reliable regression and the Article [9] substantiates the methodology for assessing the impact of changes related to groundwater and climate change on the needs for basic and environmental runoff (EFN) and showed that under average meteorological conditions, the basic runoff in the main streams still meets the requirements of EFN. It also determined that anthropogenic changes have a significant impact: drainage caused a 25-40% reduction in base runoff, groundwater abstraction caused 5-28%, and climate change will potentially cause an additional 33-70% reduction by 2050.…”