The impact of subaqueous areas on geomorphodiversity: A case study within the Wielkopolska Lakeland, northern central Poland

The main research objective was to assess geomorphodiversity – a key component of geodiversity – in a selected lowland area, including its subaqueous parts. The research also aimed to identify whether subaqueous areas influence landscape geodiversity. The subject of analysis was part of a lakeland in northern Poland that includes several large lakes. The variables (including parameters, indicators, metrics) used to assess geomorphodiversity, were selected objectively by performing a statistical analysis of 110 variables selected according to six methodological types of geodiversity studies. Ultimately, nine diverse variables were selected that lacked strong mutual correlations. Seven showed varying degrees of influence of subaqueous areas on geomorphodiversity, while the remaining ones turned out to be inappropriate for analyses in lowland areas. The highest results among the various assessments of geomorphodiversity for subaqueous areas were obtained for those variables calculated using landscape metrics and multi-criterion assessments. Previous studies on geomorphodiversity have primarily focused on terrestrial landscapes, excluding underwater areas such as lake beds. This study aims to fill that gap by incorporating both terrestrial and underwater landforms into a comprehensive framework for assessing geomorphodiversity. The provision of access to bathymetric plans has improved, as have modern technologies for identifying the bed morphology of water bodies. These improvements should encourage researchers to take such resources into account in geodiversity assessments. We conclude that omitting subaqueous areas from geodiversity analyses significantly limits the comprehensiveness of assessment of the natural environment, especially in the context of geoconservation, geoheritage, geomanagement and provision of ecosystem and geosystem services.