Construção de indice de segurança hídrica industrial: seleção de indicadores e aplicação utilizando a análise multicritério fuzzy AHP

Abstract

Water security (WS) ensures water quantity and quality, considering the social and environmental impacts of scarcity and use conflicts. This research improves the calculation of the Water Security Index (WSI) in the industrial sector. The theoretical review addressed water availability and predictability in basins and industries. Data collection was conducted through online forms, following the Ethics Committee guidelines, gathering perceptions from experts in industrial WS. The Delphi method refined five key factors as WSI indicators. In the first Delphi round (62.26% response rate), the priorities identified were: quality of captured water (81.25%), availability of alternative sources (80.65%), water reuse rate and internal water quality (78.13% each), and the consumed/authorized volume ratio (74.19%). The Content Validation Index (CVI) reached 67.56%. The second round, conducted in person, raised the response rate to 100%, improving consensus and response quality. The Delphi technique validated the main indicators with importance levels above 74%. Next, the indicator weights were defined using the Fuzzy Likert Scale, resulting in the following weights: availability of alternative sources (22.36%), consumed/authorized volume ratio (20.25%), water reuse rate (20.18%), water quality (18.69%), and specific water consumption (18.51%). Although the Fuzzy AHP methodology was initially considered, its complexity led to the adoption of simpler and more replicable approaches. In the following phase, the indicators were modeled with compatible fuzzy functions: trapezoidal, linear, and sigmoidal functions for alternative source availability; sigmoidal function for reuse rate; inverse S-shaped function for the consumed/authorized volume ratio; and sigmoidal functions for specific water consumption. Water quality was modeled to compose the Industrial Water Quality Index (IWQI), based on the average of monitored parameters: Total Chromium, Total Zinc, Total Fluoride, and Suspended Solids, in addition to other relevant parameters. The fuzzy modeling accurately adjusted the behavior of the indicators, providing a robust tool to evaluate alternative sources and support sustainable water management. The ISHI combines the five indicators into a single value that reflects industrial water security. The Industrial Water Security Panel, with a colorcoded scale from 0.0 to 1.0, facilitates result interpretation and strategic planning. Thus, the ISHI establishes itself as an innovative, adaptable, and replicable tool to strengthen water security in the industrial sector.