Integrating the Salt Suitability Index (SSI) and Sensitivity Analysis for Evaluating and Optimizing Salt Production Sites: A Case Study from South Malang, Indonesia

Salt is a strategic commodity with significant economic and ecological importance; however, Indonesia continues to face a deficit in high-quality salt production, particularly for industrial needs. This study evaluates the suitability of the southern coast of Malang Regency, East Java, as a potential new solar salt production area using the Salt Suitability Index (SSI). Field observations and secondary climate data were used to assess ten key parameters, including rainfall, soil permeability, soil type, sun exposure, air humidity, wind speed, air temperature, evaporation rate, water saturation, and road access. The results indicate that most environmental parameters fall into the very suitable (S1) category, yielding an overall SSI value of 82.5%, which corresponds to the quite suitable (S2) class. Wind speed, road access, and air humidity were identified as the primary limiting factors. Sensitivity analysis demonstrates that targeted improvements in these parameters could increase the SSI to 95%, shifting the site classification to very suitable (S1). These findings confirm that the southern coast of Malang has strong potential for salt production development, provided that technological interventions and infrastructure enhancements are implemented. The proposed SSI-based framework supports evidence-based site selection and optimization, contributing to more resilient and regionally diversified salt production in Indonesia, while promoting sustainable coastal resource management aligned with Sustainable Development Goals (SDGs) 8, 9, and 12.