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

Abstract

ABSTRACTThe 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.