Efficiency of the Log-Hyperbolic Distribution-A Case Study: Pattern of Sediment Sorting in a Small Tidal-Inlet-Het Zwin, The Netherlands


  • Daniel Hartmann
  • Dan Bowman


Grain size analysis, log-hyperbolic distribution, hyperbolic shape triangle, erosion-deposition model, population concept, tidal-inlet


Sediment sorting dispersal pattern in The Zwin tidal-inlet, The Netherlands, was studied using grain size data. The descriptive power of the log-hyperbolic distribution model, the hyperbolic shape triangle, current meters recordings and bedform analysis were applied. The process-oriented discriminating approach suggests four distinct log-hyperbolic grain size curves, related to four morphodynamic sub-environments along The Zwin Inlet. The log-hyperbolic shape indicates, in response to the governing dynamics, a gradual change from erosive, at the inlet front, to a depositional sedimentary facies inland. Applying the population concept, the Zwin supersample, the combined total sampled grain size population, falls into the right wing of the hyperbolic shape triangle, indicating a winnowed-erosional facies (p = 0.44) which is the main sedimentary fingerprint of The Zwin Inlet. It indicates winnowing-out of the suspended fraction, suppposedly complementary to a similar sedimentary heritage from the longshore drifted sediments.