Hydrogeological factors: their association and relationship with seasonal water-table fluctuation in the composite hardrock Aravalli terrain, India

Seasonal rise of groundwater level manifests aquifer recharge through infiltration. Spatial variation of aquifer recharge within the same basin or terrain is a function of terrain heterogeneity governed by different hydrogeological factors. However, assessment of relations between water-level fluctuations (WLF) with various hydrogeological factors is not straightforward. In the present study, various hydrogeological factors that could influence aquifer recharge in the deformed crystalline Aravalli terrain of India have been analysed. Frequency plots have been used to assess the variations in WLF under different geological parameter classes. Seasonal WLF associated with these factors have been compared using various statistical parameters. Parametric and non-parametric statistical tests have been used to determine the statistical significance of fluctuation difference. The study infers that saturated thickness, lineament, lineament-intersection, and drainage beside surface elevation and well depth are the main geological factors influencing aquifer recharge in the Aravalli terrain. Median values under these factors are integrated and compared with the interpolated values of mean WLF at hypothetical well locations. They are found to closely resemble each other. This infers capability and applicability of the technique in identifying key factors governing WLF, and in predicting WLF at unexplored locations.