Age-mapping and areal preservation statistics

Mapping and dating of individual Pleistocene and Holocene landforms, in the lower Rhine system has reached a stage at which preservation statistics can be analysed and compared over multiple reaches. Step-wise quantification of preservation as it develops and diverges between reaches has become possible at high temporal resolution. Combined with vertical sedimentary information this is also of use for sediment budget approaches, but in the presentation we want to focus on lateral areal preservation and non-budgeting ways of making use of this information in data-model integration in river studies.

A summary of our observations in reaches upstream and downstream of the present delta-apex will be presented. Reach-to-reach areal preservation statics are presented for (i) the Late glacial to Early Holocene period of river adaption to the climatic amelioration, (ii) the single channel meandering system in the Lower Rhine Embayment as it functioned in the Middle and Late Holocene, (iii) the diverging signals in the bifurcating confined meandering channels in the Rhine delta plain. From the record this provides information on the timescales that matter for the preservation of landforms such as cut-off meanders – adjacent to zones of reworking by younger such landforms. This is a fluvial system property that in models is typically studied through parameterization and calibration of 1D numerical models, and from the output of numerical models that treat creation and alteration of floodplains of the catchment trunk valley and downstream areas in 2D.