Groundwatch PH

Electrical and Resistivity Surveys

Electrical Resistivity Imaging (ERI / ERT) Survey in the Philippines

Groundwatch uses ERI / ERT workflows where site conditions allow to reduce uncertainty before drilling, excavation, and design-stage decisions for engineering, groundwater, geohazard, and infrastructure projects.

Definition

What this method is

Electrical Resistivity Imaging (ERI), also called Electrical Resistivity Tomography (ERT), measures electrical resistivity contrasts in the ground from controlled current injection and voltage response.

Groundwatch uses ERI / ERT workflows where site conditions allow to reduce uncertainty before drilling, excavation, and design-stage decisions for engineering, groundwater, geohazard, and infrastructure projects.

How It Works

From field measurement to interpreted model

  1. 1Electrodes are arranged along lines or grids based on project objective, target depth, and site access.
  2. 2A controlled electrical current is injected and voltage response is measured to estimate apparent resistivity.
  3. 3Inversion processing converts measurements into interpreted 2D resistivity survey Philippines sections or 3D resistivity survey Philippines models where applicable.

When to Use

Best-fit conditions for this method

  • Groundwater resistivity survey Philippines programs, well-siting, and aquifer mapping Philippines workflows
  • Resistivity survey for foundation investigation Philippines where ground variability and weak zones are concerns
  • Seepage resistivity survey Philippines and landslide resistivity survey Philippines screening before intrusive works

What It Can Help Identify

Subsurface features and signals

  • Water-bearing and conductive zones that may indicate aquifer potential or seepage pathways
  • Resistive bedrock, fill boundaries, weathering transitions, and material variability
  • Possible weak zones, cavity indicators, and target intervals for direct verification

Deliverables

What you receive

  • Survey layout, stationing, and acquisition summary
  • Interpreted resistivity sections, anomaly picks, and depth-focused interpretation notes
  • Engineering-focused report with recommendations for direct correlation

Typical Outputs

What the data looks like

  • 2D / 3D resistivity sections
  • Target zone maps
  • Depth and anomaly summaries for follow-up planning

Applications

Common applications in the Philippines

Electrical resistivity imaging Philippines investigations for groundwater exploration and deep well resistivity survey Philippines planning

Geo-resistivity survey Philippines / georesistivity survey Philippines support for foundation and subgrade assessment

Environmental baseline mapping, seepage investigation, and geohazard-oriented screening

Method Limitations

What this method cannot do alone

  • ERI results are interpreted models based on electrical resistivity contrasts.
  • Resolution generally decreases with depth.
  • Interpretation depends on contrast between soil, rock, groundwater, weathering, voids, and seepage pathways.
  • Clay, saline groundwater, metallic infrastructure, poor electrode contact, and cultural noise may affect results.
  • ERI does not replace drilling or direct investigation.
  • Results should be correlated with boreholes, drilling, geological mapping, test pits, laboratory data, or other direct information where required.

Geophysical results are interpreted models based on measured physical property contrasts. Results should be correlated with boreholes, test pits, drilling, geological mapping, laboratory data, or other direct investigation methods where required.

Related Services

Methods and applications that work together

FAQs

Frequently Asked Questions

What is the difference between ERI and ERT?

The terms are commonly used interchangeably. Both refer to resistivity-based surveys that interpret subsurface electrical contrasts from measured current and voltage response.

Can ERI or ERT replace drilling?

No. ERI / ERT reduces uncertainty and helps target drilling, but direct investigation is still required for confirmation.

How deep can an ERI / ERT survey investigate?

Depth depends on line length, electrode spacing, and site conditions, so the survey scope is defined with the project objective in mind.

What can ERI help identify in groundwater exploration projects?

ERI can help identify conductivity trends, possible aquifer-related contrasts, and weathered or fractured zones that support well-siting decisions before drilling.

What conditions can reduce ERI data quality?

Highly resistive dry ground, poor electrode contact, cultural noise, buried metal, and complex salinity or clay conditions can reduce interpretability and must be considered during scoping and QA.

Get in touch

Need an Electrical Resistivity Imaging survey for your project?

Request a Proposal and share your project objective, target depth, and available site data so we can define a fit-for-purpose ERI / ERT scope.

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