Impact of different roughness coefficients applied to relief diversity evaluation: Chełmno Lakeland (Polish Lowland)

ABSTRACT

The study deals with the use of geodiversity indices for relief diversity evaluation in lowlands (exemplified by the Polish Lowland). These indices involve three parameters: the number of relief types (n), the number of patches (m) and the roughness coefficient (r). The considered indices take the form of V(n,m) × r, where V is one of the six real-valued functions increasing with respect to n and m. The parameter r is one of the four roughness coefficients based on slopes, aspects, and elevation. Three of these coefficients are already described in the literature, while the fourth is a new coefficient conceived as a remedy for some peculiarities of the lowland relief. Overall 30 possible relief diversity indices arise (including the case of r = 1). Each index yields a relief diversity ranking of units in the study area and these rankings are compared. The impact of a roughness coefficient on the rankings is discussed and confronted with the input of the number and fragmentation of relief types. It turns out that the roughness of a relief essentially determines the relief diversity. However the observed mosaic with delimited relief types cannot be neglected. These conclusions find explanation in the geomorphologic interpretation of the relief diversity distribution.

KEYWORDS:

• Relief diversity
• geodiversity index
• roughness coefficient
• Kendall’s tau-b rank correlation
• lowland

Acknowledgements

We would like to thank the reviewers for their thorough job.

Notes on contributors

Rafał Kot holds a PhD in Geography (2005). He is a member of the Polish Association for Landscape Ecology. His main research interests include the evaluation of geodiversity, delimitation of spatial units, physico-geographical regionalization, landscape structure, and environmental protection. In 2014 he worked in the team preparing the Internet Atlas of Kuyavian-Pomeranian Voivodeship (http://atlas.kujawsko-pomorskie.pl/maps/app/map). The Map of Natural Landscapes prepared within that project, won him the first prize in the national competition organized by the Association of Polish Cartographers, and received the title of the Internet Map of the Year 2014/2015.

Krzysztof Leśniak holds a PhD in Mathematics (2005). His research concentrates around fixed point theory, metric topology, and fractal geometry. He is also interested in game theory and mathematical aspects of geography.

Additional information

Funding

Part of this work was financially supported by the Polish Ministry of Science and Higher Education [grant number N N306 721840].