100 years of mapping the Holocene Rhine-Meuse delta plain: combining research and teaching

Abstract

The history of modern soil, geomorphological and shallow geological mapping in the Holocene Rhine-Meuse delta plain goes back about 100 years. The delta plain is of very heterogeneous build up, with clayey and peaty flood basins, dissected by sandy fluvial distributary channel belts with fine textured levees grading into tidal-influenced rivers and estuaries. Several generations of precursor rivers occur as alluvial ridges and buried ribbon sands. They form an intricate network originating from repeated avulsions, back to 8000 years ago. Present rivers have been embanked since ca. 1250 AD and the delta plain ( 3000 km2) has been reclaimed for agriculture. Soils are young and subject to oxidation and compaction. As time proceeded, methods and approaches have changed. The introduction of high-resolution Lidar elevation data allowed to re-evaluate earlier collected borehole data and to develop more efficient field data collection strategies. While in the 1960-1990s we taught students ‘how to map a data-sparse area’, we now train students ‘to critically evaluate heaps of existing data and maps to improve mapping’. This also raises the awareness of the distinction between observation and interpretation, when different types of information are combined in mapping. This attitude change and maturity also echoes through current research in soil, geomorphology and geology in the delta.