2026-10-13T23:47:32Z https://api.figshare.com/v2/oai

oai:figshare.com:article/33871972 2026-09-17T05:51:59Z category_87 portal_316 item_type_3 month_year_09_2026

Supplementary file 1_Exploring spatial variability in the physical and chemical properties of urban soils using electrical resistivity tomography.docx Camille Ribler (25002235) Thomas Z. Lerch (12559804) Henri Robain (15648608) Soil Science electrical resistivity tomography organic matter spatial variability (SV) trace elements urban soils soil sampling strategy <p>Urban soils exhibit complex spatial heterogeneity resulting from the superposition of natural pedogenetic processes and variable anthropogenic disturbances. To optimize land-use planning and avoid inappropriate uses, it is essential to accurately characterize the spatial variability of soil properties and potential contamination. Electrical Resistivity Tomography (ERT), a geophysical method developed over several decades, is well suited to describe soil variability in highly heterogeneous, human-disturbed environments. Resistivity values are mainly controlled by water content within soil porosity, and thus by texture and structure. However, except in highly polluted industrial sites, the relationship between soil resistivity and physico-chemical properties, organic matter composition, and contaminants remains poorly documented. Here, we develop an ERT-based multivariate framework in which high-resolution vertical resistivity profiles are classified using Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) to objectively delineate spatially coherent soil units and guide a balanced stratified soil sampling design.At an urban site near Paris (Bondy, France), ERT was used to generate high-resolution maps of vertical geo-electrical profiles, which supported a stratified sampling design. At most depths, the four soil types identified by ERT differed significantly in texture, chemical properties, and organic matter composition, as shown by infrared spectroscopy. Trace elements (TE), particularly lead (Pb), were detected, but no significant differences among soil types were observed except in deeper layers. Variations in physico-chemical conditions, especially soil moisture, may influence TE speciation and mobility, potentially affecting biota. The subsequent independent characterization of 120 soil samples showed significant differentiation among the ERT-derived classes for several physical, chemical, elemental and organic-matter characteristics, supporting the use of geoelectrical units as operational sampling strata.</p> 2026-09-17T05:51:59Z Dataset Dataset 10.3389/fsoil.2026.1924576.s001 https://figshare.com/articles/dataset/Supplementary_file_1_Exploring_spatial_variability_in_the_physical_and_chemical_properties_of_urban_soils_using_electrical_resistivity_tomography_docx/33871972 CC BY 4.0