Vertical Profiles

Vertical profiles provide a comprehensive view of all measurements for a sample relative to depth. They display physico-chemical parameters, elemental concentrations, molecular concentrations, and isotopic ratios on a single vertical axis to reveal significant geochemical transitions within a borehole column at a glance. This page covers IsoFind's Vertical Profiles view, its display conventions, data sources, and the sample comparison mode.

Borehole Convention

IsoFind follows the standard borehole convention: the vertical axis represents depth in meters, with zero at the surface and values increasing downwards. This convention is explicitly stated in the view's title bar. While it inverts standard mathematical intuition (where Y increases upwards), it aligns with geological interpretation: depth increases as you go down.

This convention is consistent with well logs, stratigraphic cross-sections, and hydrogeological reports. Users importing data from borehole logs or core analyses can use depth values as-is without axis transformation.

Accessing the View

The Vertical Profiles view is the fifth tab in the Samples section, following Geochemistry and Molecules. It loads data for the selected sample on demand via the dedicated GET /api/samples/{id}/depth-profile endpoint. This endpoint aggregates measurements from four distinct tables, tagging them by their source table.

Source Table	Measurement Types	Display Category
sample_physicochemistry	pH, Eh, DO, T, conductivity, salinity	Physico-chemical Conditions
sample_geochem	Elemental concentrations (Ca, Mg, Fe, Cr, As...)	Elemental Geochemistry
sample_molecules	Molecular concentrations (PFAS, pesticides, PAH...)	Molecular Concentrations
sample_isotope	δ ¹³C, δ ²H, δ ⁵³Cr, ⁸⁷Sr/⁸⁶Sr and other isotopic ratios	Isotopic Ratios

For a measurement to appear in the vertical profiles, it must have a non-zero depth value. Measurements without depth (typically weighted averages or mixture analyses) are ignored by this view and remain available in their native form within the Geochemistry and Molecules tabs.

The Four Charts

The view presents one SVG chart per category. Each chart uses an accent color for quick visual identification. The horizontal axis represents the value (concentration, δ, pH), while the vertical axis represents inverted depth.

Category	Accent Color	Typical Content
Physico-chemical Conditions	Purple	Multiple overlaid curves: pH, Eh, DO, T on the same axes
Elemental Geochemistry	Green	One curve per element, values in mg/kg or mg/L
Molecular Concentrations	Orange	One curve per molecule, values in ng/L or µg/L by family
Isotopic Ratios	Indigo	δ ¹³C, δ ²H, δ ⁵³Cr, Pb ratios, ⁸⁷Sr/⁸⁶Sr

Grouping by category improves readability compared to a global display: pH values (6 to 8) and chromium concentrations (mg/kg) do not need to share the same axis, avoiding scale compression and illegible overlays. Each card maintains its own dynamic range.

Multi-parameter Points within a Chart

A single chart can display several overlaid parameters if the category allows it. For physico-chemical conditions, pH and Eh share the same chart with different colors. For geochemistry, each element present is assigned a distinct color from the view's palette. The legend displays the parameters present and their respective colors.

The palette used for multiple curves within a single category includes ten distinct colors, allowing up to ten elements or molecules to be displayed simultaneously before repeating a color code. Colors are ordered to maximize contrast between adjacent curves.

This multi-curve management allows for the visualization of degradation cascades at depth. For example, a chlorinated solvent plume can simultaneously show PCE at the surface, TCE at 5 m, cDCE at 15 m, and VC at 25 m within the same Molecular Concentrations chart. The cascade then becomes immediately legible graphically.

A / B Comparison Mode

The selection bar allows you to switch to comparison mode via the "Compare" button. In Single mode, only one sample is displayed (Selector A in indigo). In Comparison mode, a second selector appears (Selector B in amber), and each chart splits into two side-by-side panels sharing the same axis scales.

Mode	Layout	Use Case
Single	2 columns × 2 rows grid, one sample	Detailed review of a single borehole
Comparison	1 column × 4 rows grid, two samples side-by-side	Upstream vs. downstream, before vs. after remediation, control point vs. impacted point

Color coding persists between the two panels: Sample A retains its indigo identity, and Sample B its amber identity. This visual consistency helps track a parameter across two boreholes. The selection bar remains at the top of the view at all times, allowing you to change either sample without exiting comparison mode.

Interpreting a Vertical Profile

The value of vertical profiles lies in revealing geochemical transitions occurring within the water or soil column. Several classic signatures are immediately visible.

Observed Signature	Probable Interpretation
Sharp Eh drop between two depths	Crossing an oxic/anoxic boundary, transition from unconfined to confined aquifer
Fe(II) increase correlated with Eh drop	Active reduction zone, dissolution of oxyhydroxides
NO₃⁻ decrease in reduced zone	Active biological denitrification
δ¹⁵N enrichment at depth	Isotopic evidence of denitrification (fractionation leaving heavy residual)
PCE → TCE → cDCE → VC cascade with depth increase	Reductive dechlorination in anoxic zone
Concentration peak at a specific depth	Source level, clay layer trapping a contaminant, natural enriched horizon
Stable ⁸⁷Sr/⁸⁶Sr throughout the column	Single dominant geological source
Variable ⁸⁷Sr/⁸⁶Sr with depth	Succession of different geological layers, stratified lateral inflows

Contribution to 3D Simulation

Vertical profiles are not just for visualization; they directly feed the 3D simulation engine. The stratigraphic structure deduced from profiles can be used to configure lithological layers in the simulation, and depth-specific physico-chemical conditions become boundary conditions for the simulated domain.

Simulation Usage	Consumed Fields
Defining stratigraphic layers	Marked geochemical transitions (Eh, conductivity) serve as layer boundaries
Initial chemical species conditions	Measured concentrations by depth as an initial prior
Local speciation	pH, Eh, DO by depth for redox speciation resolution
A posteriori validation	Comparison of simulated values against measured profiles

Entering Measurements with Depth

For a measurement to appear in a vertical profile, it must be recorded with a valid depth. Each source table has its own depth field, populated either during manual entry or CSV import.

Source	Depth Field	Unit
Physicochemistry	depth_m	meters
Elemental Geochemistry	depth_m	meters
Molecules	depth_m	meters
Isotopes	depth_m	meters

For samples from continuous cores or multi-level boreholes, the CSV import accepts a depth_m column (or variants recognized by the semantic resolver: Depth, depth, profondeur, profondeur_m). Depth is systematically converted to meters even if the source unit is in feet or centimeters.

Note on samples integrated over several meters: a core analyzed from 5 to 8 m does not have a single depth but an interval. By convention, IsoFind stores the median depth (6.5 m), with bounds stored in the depth_top_m and depth_bottom_m fields when provided. For precise tracking of heterogeneities, point analyses with a single depth are preferred over integrated analyses.

Displayed Point Counter

The selection bar displays a counter to the right of the sample name showing the number of measurements with a depth. This counter allows you to quickly determine if a sample contains enough data to generate a relevant vertical profile. A sample without depth-assigned measurements will display "0 point(s) with depth," and the four charts will remain empty.

Export and Reporting

Vertical profiles can be included in reports generated by the Reports module. The dedicated depth_profiles block generates a PDF with the selected sample's four charts, reproduced in A4 portrait format with legends and scales. In Comparison mode, the block prints both samples side-by-side.

Current Limitations

The view is centered on one sample (or two in comparison). To compare more than two boreholes simultaneously, use the 2D Mapping module.
Profiles do not yet handle interpolation between measured depths: curves are drawn by connecting measured points without spline smoothing or kriging.
Log scales are not automatic. If a parameter varies over several orders of magnitude (e.g., PFAS in ng/L), the linear axis may compress low values. A log scale option per chart is on the roadmap.
Depths below 100 m are rare in IsoFind's forensic use cases; the view has been optimized for the 0 to 50 m range typical of shallow aquifers.

Learn More

Core Platform: General navigation of the Samples window.
Redox Speciation: Interpreting Eh and DO transitions at depth.
Stratigraphic Layers: Using profiles in 3D simulation.
The 8 Data Families: Overview of sample data types.