Hydrogeochemical Evaluation of Surface and Groundwater for Irrigation Suitability and Corrosion Potential in a Semi-arid Coastal Region of Western Gujarat, India

Abstract

In semi-arid coastal regions, increasing water demand and salinity intrusion pose significant challenges to the quality and sustainability of surface and groundwater resources. Understanding the hydrogeochemical characteristics of water is essential for evaluating its suitability for irrigation, industrial use, and long-term resource management. This study presents a comprehensive hydrogeochemical and statistical assessment of surface and groundwater quality in the Gir Somnath District and Diu region of Gujarat (GSDD), India. A total of 57 various water samples were systematically collected and analysed for major physicochemical parameters to evaluate their suitability for drinking, irrigation, and industrial purposes. GSDD region’s surface and groundwater is mostly alkaline in nature. However, its composition varies greatly depending on geological formations, evaporation, and human activities. The ionic dominance pattern is Na⁺ > Mg²⁺ > Ca²⁺ > K⁺ and Cl⁻ > HCO₃⁻ > SO₄²⁻ > CO₃²⁻ > NO₃⁻ > F⁻ indicating strong salinity control in coastal aquifers. The irrigation suitability indices and USSL (US salinity laboratory) classification show that most of the samples are either suitable or moderately suitable. However, the presence of salinity and magnesium could potentially harm soil structure and reduce crop yields. Industrial indices indicate a dual tendency of scaling and corrosion, suggesting the need for appropriate water treatment before industrial use. Multivariate statistical analysis and hydrochemical facies (Piper diagrams) confirm that groundwater chemistry is primarily governed by rock–water interaction, ion exchange processes, and salinity impact. This study of the GSDD region reveals that its surface and groundwater resources exhibit moderate suitability for various applications. However, it is very important to use sustainable water management strategies and salinity control measures to prevent deterioration and make sure that these water resources will be useful for a long-term stability.