Tools for Compatibility Screening in Shallow Subsurface Uses via Integrated Geophysical Ground Modelling with Uncertainty Assessment

Geophysical surveys are widely used to characterize lithological and structural variability in the subsurface. They support the design of shallow, low-temperature geothermal systems, the delineation of freshwater aquifers, and the assessment of investment risk associated with subsurface interventions. Evidence from the authors’ projects and from published case studies shows that a detailed ground model is central to environmental impact assessment, definition of technical boundary conditions, and planning of synergies between operation and its interactions with existing infrastructure, local communities, and the natural environment. In practice, this requires translating interpretation results into project-relevant parameters, including lithology distribution, layer thickness, key boundary geometries, disturbed zones, and hydrogeological conditions, together with risk indicators that describe the likelihood of adverse ground and groundwater conditions at the planned site. Interpretation remains challenging because ambiguity arises from limited resolution and survey coverage and from the inherent heterogeneity of unconsolidated sediments.
This paper presents an integrated workflow for shallow investigations that combines seismic, electrical resistivity and electromagnetic methods to reduce ambiguity through consistent multi-method integration and explicit uncertainty quantification. The workflow assumes that the geological model must both respect method-specific limitations and represent the subsurface architecture realistically enough to support engineering decisions. Spatial geostatistical modelling is used to capture variability and to propagate uncertainty into maps and cross-sections of key boundaries and properties. Geostatistical and Artificial Intelligence tools support data fusion, recognition of structural features and lithological zones, and systematic comparison of alternative geological scenarios. The resulting ground model is delivered as a most-likely realization accompanied by uncertainty products, including probability-based representations of lithology and confidence intervals for boundary positions, so that the outputs can be used directly in technical and environmental risk assessment and in selecting the preferred design variant.
The workflow is demonstrated on experimental field data collected during a seismic project carried out in Poland, in an area with unfavorable geological conditions that generate highly ambiguous seismic responses. Although the survey was not originally intended for shallow geothermal design, it enabled development and testing of the integrated workflow and the formulation of practical guidance for siting shallow installations. The study focuses on ambiguity drivers such as strong attenuation and scattering in unconsolidated deposits, lateral and vertical velocity variability, and locally changing saturation, and on mitigation measures based on survey design, processing choices, and integration with electrical methods. The site is representative of settings with heterogeneous Quaternary cover and thick unconsolidated sediments under variable hydrogeological conditions, which also supports transfer of the methodology to the exploration and characterization of shallow freshwater resources. The final outcome is a coherent methodological description and decision oriented recommendations that support transparent, defensible assumptions during planning and implementation under uncertainty.