Geographical variability of environmental parameters versus GPS precision: toward a better sampling strategy

Area of Science:

• Sedimentary geology
• Geospatial analysis
• Environmental monitoring

Background:

• Characterizing sedimentary environments requires understanding spatial variability to avoid misinterpreting temporal changes.
• Establishing reference stations for long-term monitoring necessitates accounting for both temporal and spatial variations.
• Global Navigation Satellite System (GNSS) precision highlights the significance of small-scale spatial heterogeneity.

Purpose of the Study:

• To assess the impact of spatial variability on sedimentary environment characterization.
• To determine the optimal number and arrangement of samples for reliable temporal tracking.
• To differentiate between true temporal changes and spatial variations in sedimentary parameters.

Main Methods:

• Analysis of spatial variability at the scale of GNSS precision.
• Evaluation of spatial distribution for parameters including InC, TOC, TS, and fine fraction percent.
• Comparison of sampling strategies for temporal monitoring.

Main Results:

• InC, TOC, and TS exhibit low spatial variability, enabling temporal tracking with single samples.
• Fine fraction percent demonstrates high spatial variability even over short distances.
• The required number and arrangement of replicates are environment- and parameter-dependent.

Conclusions:

• Temporal tracking of sedimentary environments using GNSS requires careful consideration of spatial variability.
• Parameters with low spatial variability (e.g., TOC) are suitable for long-term monitoring with minimal sampling.
• Parameters with high spatial variability (e.g., fine fraction percent) necessitate repeated spatial assessments during sampling periods.