GROUNDWATER EXPLORATION AND DEVELOPMENT FOR THE CONSTRUCTION OF A LARGE-SCALE GROUNDWATER SUPPLY SYSTEM: A CASE STUDY OF TONG KHOB PROJECT, KHOK SI SUPHAN DISTRICT, SAKON NAKHON PROVINCE, THAILAND

Abstract

The objective of this research was to conduct a geophysical exploration and evaluate groundwater potential for the construction of a large-scale groundwater supply system in Tong Khob Subdistrict, Sakon Nakhon Province, an area facing severe water scarcity due to soil conditions unable to retain surface water. The methodology involved Electrical Resistivity Tomography (ERT) and Vertical Electrical Sounding (VES) at 43 survey points using the Schlumberger array, complemented by Electrical Logging techniques including Single-Point Resistivity (SPR) and Gamma Ray (GR). The results revealed that the subsurface geology consists of the Khok Kruat Formation (Kkk), characterized by sandstone and conglomerate layers. Analysis of resistivity graphs identified 10 high-potential locations exhibiting "Clean Sand" characteristics, marked by significantly high resistivity and low GR values, indicating high-quality aquifers. Subsequent Step-Drawdown Tests confirmed a sustainable production capacity of 2–10 m³/hr. These findings were utilized to design an efficient water distribution network and sustainable management plan, effectively addressing drought issues and improving the quality of life for the local community.

Keywords: Geophysical Exploration, Groundwater Development, Khok Kruat Formation, Electrical Resistivity, Aquifer Potential Assessment