Applicability and relevance of water scarcity models at local management scales: Review of models and recommendations for Brazil

• Published in: Environmental impact assessment review 2018-09, Vol.72, p.126-136
• Main Authors: de Almeida Castro, Ana Lídia, Pereira Andrade, Edilene, de Alencar Costa, Mateus, de Lima Santos, Tayane, Lie Ugaya, Cássia Maria, Brito de Figueirêdo, Maria Cléa
• Format: Article
• Language: English
• Subjects: Availability; Balances (scales); Case studies; Characterization factors; Comparative studies; Criteria; Data processing; Deprivation; Ecosystems; Environmental conditions; Environmental impact; Environmental protection; Freshwater use; Geopolitics; Historical account; Hydrologic data; Hydrologic models; Hydrology; Industrial development; Life cycle analysis; Life cycle assessment; Life cycle engineering; Life cycle impact assessment; Life cycles; Local management; Measurement; Public policy; Regionalization; Robustness; Scarcity; Semi arid areas; Semiarid lands; Semiarid regions; Shortages; Uncertainty; Water consumption; Water scarcity; Water scarcity footprint; Water shortages; Water stress; Water treatment; Watersheds
• ISSN: 0195-9255; 1873-6432
• DOI: 10.1016/j.eiar.2018.05.004

With water shortages increasing worldwide, several Life Cycle Impact Assessment (LCIA) models have been developed for assessing the potential impacts of water consumption (deprivation) on ecosystems and human health. Each model uses different water scarcity concepts, measurement scales, and indicators, resulting in distinct characterization factors (CFs) available for the same region over time. However, to date, no previous work has compared water scarcity models to identify those more suitable for countries outside of Europe, considering national hydrological divisions and environmental conditions. Furthermore, no previous studies have investigated the sensitiveness of background hydrological data, applied to calculate water scarcity CFs, in regions that historically experience water scarcity, such as the Brazilian semiarid region. This is important because global hydrological data may present high uncertainty and indicate low scarcity in regions that suffer with water scarcity issues. Therefore, this work initially evaluated midpoint models for water scarcity and recommended the most appropriate models for application at the Brazilian hydrographic division level, defined by the Brazilian Water Agency (ANA). A critical review of twelve midpoint models was performed based on four main criteria: (i) indicator broadness; (ii) scientific robustness; (iii) availability of CFs for Brazil; and (iv) regionalization potential of CFs for ANA geopolitical hydrographic divisions, considering the availability of national data. Each criterion was given a score of 1 to 5 for each analyzed model and a recommendation was made based on the final score, obtained by averaging the scores of each criterion. Results showed that the best-rated models were those that adopted the monthly Water Stress Index (WSI) and the AWARE index. Both models were robust, presented CFs at a monthly scale, and could be partially regionalized by applying national monitoring data available in national databases. Nonetheless, none of these models applied a broad water scarcity concept that encompassed both physical and economic water scarcities, nor presented CFs for the Brazilian hydrographic divisions. Furthermore, a case study was performed, comparing the CFs provided by AWARE and WSI with the regionalized values, which were calculated using national hydrological data. This case study focused on the São Francisco watershed and on the Rio Verde Grande, a smaller watershed belonging to the São Fran