Inter-Annual Comparative and Correlation Analysis of Seasonal Limnological Characteristics of Urmil Dam (Singhpur Barrage), Madhya Pradesh, Central India

Abstract

Freshwater reservoirs are strongly influenced by seasonal hydrological changes, yet integrated assessments combining annual comparisons and multivariate statistical analysis remain limited for Singhpur Barrage Reservoir, Madhya Pradesh, India. This study evaluated physicochemical water-quality variations across winter, summer, and monsoon during 2024–25 and 2025–26 using 24 observations. Descriptive statistics, normality testing, parametric and non-parametric comparisons, Spearman correlation, principal component analysis, and hierarchical cluster analysis were applied. Significant seasonal variation occurred in electrical conductivity, pH, chloride, alkalinity, fluoride, iron, total hardness, calcium, magnesium, sulphate, sodium, and potassium. Summer generally exhibited higher ionic and mineral concentrations, while monsoon conditions were associated with increased suspended matter and reduced transparency. Annual differences were mainly observed for water temperature, chloride, and selected mineral-related variables. Strong positive correlations were found among conductivity, sulphate, magnesium, potassium, iron, and hardness, whereas transparency showed a strong negative relationship with suspended solids. Five principal components explained 87.206% of the total variance, although the low KMO value indicated that the PCA findings should be interpreted cautiously. Hierarchical clustering identified mineral, ionic, physical, optical, and general physicochemical groups. The findings highlight the importance of seasonal and long-term monitoring for sustainable reservoir management and water-resource planning.