Semi-automatic analysis and interpretation of sediment profile images

Sediment Profile Images (SPIs) are widely used for benthic ecological quality assessment under various environmental stressors. The processing of the information contained in SPIs is slow and its interpretation is largely operator dependent. We report here on a new software: SpiArcBase, which allows for a semi-automatic analysis of SPIs and facilitates the interpretation of observed features. SpiArcBase enhances the objectivity of the information extracted from SPIs, especially for the assessment of the apparent Redox Potential Discontinuity (aRPD). This new software also allows the user to create and manage a database containing original SPIs and corresponding derived pieces of information. Examples of the use of SpiArcBase for SPIs collected during a case study carried out within the Rhône River Prodelta are provided. Correlations between: (1) visually and automatically assessed aRPD and Benthic Habitat Quality Index (BHQ), and (2) automatically assessed aRPD and BHQ and surface sediment organic carbon support the use of this new software.