Evaluating the Suitability of Multi-Scale Terrain Attribute Calculation Approaches for Seabed Mapping Applications

Abstract

The scale dependence of benthic terrain attributes is wellaccepted, and multi-scale methods are increasingly applied for benthic habitat mapping. There are, however, multiple ways to calculate terrain attributes at multiple scales, and the suitability of these approaches depends on the purpose of the analysis and data characteristics. There are currently few guidelines establishing the appropriateness of multi-scale raster calculation approaches for specific benthic habitat mapping applications. First, we identify three common purposes for calculating terrain attributes at multiple scales for benthic habitat mapping: (i) characterizing scale-specific terrain features, (ii) reducing data artefacts and errors, and (iii) reducing the mischaracterization of ground-truth data due to inaccurate sample positioning. We then define criteria that calculation approaches should fulfill to address these purposes. At two study sites, five raster terrain attributes, including measures of orientation, relative position, terrain variability, slope, and rugosity were calculated at multiple scales using four approaches to compare the suitability of the approaches for these three purposes. Results suggested that specific calculation approaches were better suited to certain tasks. A transferable parameter, termed the 'analysis distance', was necessary to compare attributes calculated using different approaches, and we emphasize the utility of such a parameter for facilitating the generalized comparison of terrain attributes across methods, sites, and scales.

Optimizing the Scale of Observation for Intertidal Habitat Classification through Multiscale Analysis

“…The upper limit of 31 cm was selected to correspond with what can be acquired from other remote sensing sources (e.g., occupied aircraft imagery, satellite imagery). This method of varying the resolution scale of input variables (sometimes referred to as coarse-graining) has been used when studying marine environments, often within the context of habitat selection models [33][34][35][36], and was identified as the most appropriate method to use when wanting to characterize specific features or processes [17].…”

“…Multiscale approaches have become critical to ensure that the scales of observation and analysis match the ecological scales relevant to a particular system [16,17] and can help identify the most appropriate scales of observation and analysis for a given purpose (e.g., [18,19]). In theory, using scales that best capture the patterns of interest improves classification accuracy.…”

Spatial distribution of benthic flora and fauna of coastal placentia bay, an ecologically and biologically significant area of the island of newfoundland, atlantic Canada

“…using moving-windows of varying sizes), as no single scale can account for all ecological processes of a benthic ecosystem (Dolan, 2012;Lecours et al, 2015). All features (except for BPI) were derived using a 3x3-cell window, with additional scales obtained using the "calculate-average" approach (Dolan and Lucieer, 2014;Misiuk et al, 2021), by focal averaging using increasing window sizes (13 × 13-and 35 × 35-cell windows; Table 2). BPI layers were calculated by setting the outer and inner radii (in cells) of an annulus (ring-shape) and calculating the mean elevation value of all cells within the analysis neighborhood (Walbridge et al, 2018).…”

Editorial: Seafloor Mapping of the Atlantic Ocean

“…While ground-truthing data are very fine-scale, acoustic data (bathymetry and backscatter) and other environmental data are usually collected at a coarser resolution. How we integrate such multiscale information remains unclear and is an active field of research (e.g., Misiuk et al, 2021). There is a tradeoff between the comprehensiveness of the environmental characterization and the level of detail provided: the inclusion of a broader-scale environmental dataset may constrain the analysis to a coarser resolution, potentially losing important information.…”