Development of Sustainable Hydrological Index

Sustainability indices are valuable tools for integrating complex environmental data into composite metrics that support decision-making in resource management. While widely used in the water sector, most existing indices focus broadly on social, economic, and environmental components, often overlooking the physical processes that define hydrological systems. This study introduces the Sustainable Hydrological Index (SHI)—a novel indicator designed specifically to assess hydrological sustainability. The SHI is structured around four main pillars: Natural Systems, Artificial Systems, Climate Change Impacts, and Variations. Each pillar includes indicators representing critical aspects of hydrological functioning, such as precipitation variability, groundwater levels, evapotranspiration, infrastructure performance, and climate-related extremes. To ensure comparability, indicators are normalized using min-max scaling and z-score standardization, depending on data distribution. A key innovation lies in the use of Genetic Algorithms (GAs) to optimize the weighting and aggregation of indicators. This approach minimizes subjectivity and enables the model to identify optimal configurations that reflect hydrological performance. As the first index dedicated solely to hydrology, the SHI addresses a significant methodological gap. It offers a practical, data-driven framework for assessing system resilience, informing planning, and supporting sustainable water management strategies across diverse hydrological contexts.