The study evaluates whether buried paleochannels can provide shallow groundwater to drought-affected communities with limited access to irrigation, surface water, and productive deep aquifers. The authors combine time-lapse Google Earth imagery, geological interpretation, field surveys, two-dimensional (2D) electrical resistivity imaging, and two verification boreholes.
The integrated workflow identified paleochannel-like bodies approximately 50–160 m wide, potentially extending to a few hundred metres, and roughly 10–20 m deep. Boreholes DC-1 and DC-2 encountered shallow groundwater at 5–9 m and 3–12 m, respectively, and reportedly yielded 4–4.2 m³/h. Borehole sediments were interpreted as alluvial-fluvial deposits. The authors therefore present the approach as a potentially lower-cost pilot method for locating shallow groundwater where deep groundwater prospects are poor.
The boreholes support the presence of water-bearing shallow sediments at the two selected drilling locations. However, the paper does not report long-duration pumping tests, seasonal monitoring, groundwater quality, storage estimates, or a broader validation sample, so it does not establish the aquifer's long-term sustainable yield or regional reliability.
Dan Chang District lies partly outside irrigation coverage and experiences recurrent water shortages. The authors state that confined aquifers in the district are generally deeper than 40 m and have limited yields of 1–10 m³/h. Although the Krasiao reservoir is a major regional water source, many Dan Chang communities receive little benefit because its streams flow toward other districts.
The study's objective is to locate buried paleochannels in Nong Makha Mong Subdistrict and test whether they contain accessible shallow groundwater. It uses remote sensing and geology to identify candidates, then geophysical imaging to refine the channel geometry and guide drilling.
A paleochannel is a former river or channel that has been buried by younger sediments. Such channels may contain permeable sand and gravel capable of storing shallow groundwater, but their surface expression can be obscured by sediment deposition and land-use change. The paper reviews aerial photographs, digital elevation models, electrical and electromagnetic surveys, ground-penetrating radar, and seismic refraction as methods previously used to locate or characterize paleochannels.
The authors focus on Nong Makha Mong because its geomorphology suggests abundant buried channels. Their proposed sequence is to identify likely channel traces remotely, delineate them more precisely with 2D resistivity imaging, and drill at selected targets.
Dan Chang District forms a basin that slopes gradually from west to east. The district includes Ordovician limestone with marble and calc-silicate, phyllite and slate, and Quaternary colluvial deposits containing rock fragments and clay. It lies upstream of the Mae Klong and Tha Chin river basins, east of the Tanaosri mountain range, in an area described as part of Thailand's rain shadow. The authors report that average rainfall in Dan Chang is lower than the provincial average.
Small streams and inferred paleochannels in Nong Makha Mong may have been buried through changes in depositional conditions and land use. Figure 1 places the study area within the district's geological and hydrological context.
The authors examined Google Earth time-lapse aerial imagery to infer the approximate positions, directions, and orientations of buried channels. Differences in vegetation colour were treated as surface indicators of subsurface moisture or sediment contrasts. Figure 2 compares imagery from January 2001, January 2014, April 2017, and April 2019; the interpreted channel boundaries change in visibility as agricultural land use develops.
This stage provided preliminary targets rather than direct confirmation. The paper also states that high-resolution topography was generated from aerial photographs, although it gives little detail about the production or analysis of that map.
Five resistivity lines with a combined length of 1,415 m were surveyed using a Wenner-Schlumberger configuration. The setup used 48–72 electrodes at 5 m spacing. Figure 3 shows the line locations and the later DC-1 and DC-2 boreholes.
The authors calculate apparent resistivity using:
with
where is apparent resistivity, is measured resistance, is the spacing associated with the A–M or N–B interval and the M–N potential-electrode pair as described by the authors, and is the A–B electrode spacing. The paper also defines as the ratio associated with A–M or N–B spacing; corresponds to a Wenner-like configuration. Figure 4 diagrams the array. Measurements were inverted in Res2Dinv to generate subsurface resistivity sections.
The authors interpret potential paleochannels on survey lines 1–3 (Figure 5). Their estimated dimensions are about 50–160 m in width, possibly up to several hundred metres, and about 10–20 m in depth.
For lines 1–3, they divide the subsurface into three broad resistivity zones:
Lines 4 and 5 differ: they show a high-resistivity upper zone toward the centre to north end and low resistivity of roughly 2–10 Ω·m beneath it. Figure 5 reports fifth-iteration root-mean-square inversion errors of 1.8%, 2.8%, 2.4%, 2.4%, and 1.8% for lines 1–5, respectively. These values indicate numerical fit of the inversion to the measurements, not independent proof of the geological interpretation.
The lithological logs from boreholes on lines 2 and 3 are reported to correspond with the resistivity interpretations (Figure 6).
The two discovery wells reportedly produced 4–4.2 m³/h. The borehole sediments are interpreted as alluvial-fluvial deposits. These drilling results ground-truth the presence of shallow groundwater and channel-fill sediments at the selected sites, though they do not by themselves validate every resistivity anomaly or establish the full lateral continuity of the aquifer.
The authors conclude that integrating remote sensing, geology, and 2D resistivity imaging successfully located a shallow groundwater-bearing paleochannel in Nong Makha Mong. They summarize the productive depth as 3–15 m and the groundwater yield as approximately 4 m³/h. Because shallow wells are relatively inexpensive to drill, they propose the work as a pilot approach for communities facing severe drought and having limited deep-groundwater or surface-water potential.
The study demonstrates a staged exploration workflow: low-cost imagery screening can reduce the area requiring field investigation; 2D resistivity can then guide borehole placement; and drilling provides direct verification. In settings similar to Nong Makha Mong, this may reduce the cost and risk of drilling shallow wells compared with untargeted exploration. Actual deployment would still require site-specific confirmation and an assessment of water quality and sustainable abstraction.
Muangnoi, S., Chaimanee, N., & Pananont, P. (2022). Integrated studies to investigate paleochannel aquifer in Dan Chang District, Suphan Buri Province, Western Thailand. Journal of Physics: Conference Series, 2145, 012050. https://doi.org/10.1088/1742-6596/2145/1/012050