The resistivity investigations in hard rock regions by and large reflect in A, H or HA type of sounding curves. In hard rock terrains especially granites and charnokites, deciphering the actual depth to the aquifer zone using conventional resistivity curve matching technique is difficult. Hence, drilling of bore wells and tapping fractured aquifer at desired location and depth, based on data interpretation by conventional method may not yield aquifer zones at interpreted depth. In this paper the basic resistivity (VES) data from granite terrain was subjected to a semi-quantitative approach, namely factor analysis, in order to eliminate the suppression effect from the overburden and to refine the depth to aquifers in a granite terrain. The hindrance in clarity to the fractured aquifer depth had prompted to adopt in examining the raw data of VES within a small area of 2 sq. km. in a granite terrain of Nalgonda district, Andhra Pradesh, India. The factor analysis showed good correlation with the actual aquifer depth drilled. This technique was adopted by geologists, hydrologists and consultants in the field of groundwater exploration of different state and other groundwater divisions.
Author(s) Details:
Rolland Andrade
Central Water & Power Research Station, Pune-24, India.
Recent global research developments in Groundwater Mapping in Granite Watersheds Using VES Techniques
Thematic Layers for Mapping: Researchers often use thematic layers such as land use and land cover (LULC), geomorphology, soil, drainage density, slope, lineament density, elevation, groundwater level, and geology maps. These layers help create a comprehensive picture of the groundwater potential in a given area using remote sensing and geographic information system (GIS) techniques [1] .
Groundwater Level Maps: Groundwater level maps provide valuable information for well placement and hydrological system design. Remote sensing data and GIS techniques are increasingly used to map groundwater capacity, especially in inaccessible regions, saving time and resources [2].
Geospatial Modeling for Groundwater Potential: Geophysical parameters, such as resistivity, can be used to estimate groundwater potential. Geospatial modeling produces groundwater potential prediction index (GPPI) maps, which classify areas into different potential classes (e.g., low, medium, medium–high, and high). These maps guide sustainable water resource management [3].
References
- Shinde, S.P., Barai, V.N., Gavit, B.K. et al. Assessment of groundwater potential zone mapping for semi-arid environment areas using AHP and MIF techniques. Environ Sci Eur 36, 87 (2024). https://doi.org/10.1186/s12302-024-00906-9
- Patel, A., Zala, K., Solanki, K. (2022). Ground Water Potential Zone Mapping Using Remote Sensing and GIS in Saurashtra Region of Gujarat, India. In: Ashish, D.K., de Brito, J. (eds) Environmental Restoration. F-EIR 2021. Lecture Notes in Civil Engineering, vol 232. Springer, Cham. https://doi.org/10.1007/978-3-030-96202-9_14
- Bayode, S., Mogaji, K.A. & Egbeyemi, O. Modeling of geophysical derived parameters for groundwater potential zonation using GIS-based multi-criteria conceptual model. Appl Water Sci 14, 19 (2024). https://doi.org/10.1007/s13201-023-02056-4
