Quick scan ondergrond IJssel Vechtdelta : bouwstenen voor een visie op een robuust en veerkrachtig ecosysteem

Summary

This report describes the genesis and potential of the subsoil of the area designated as “IJssel Vecht delta”. The report contains one of preliminary studies for drawing up a vision for the area within the framework of the Programmatic Approach to Large Waters (PAGW). On behalf of the other PAGW partners, Staatsbosbeheer draws up the vision process for the IJssel-Vecht Delta and is the client for this study. The subsoil of the (current) IJssel Vecht delta is formed in an estuarine environment. A large peat area has been cut and swept away by erosion and sedimentation from the sea, rivers and streams. This resulting in a wide variety of ecological conditions. From the early Middle Ages onwards, man and society intervened more and more in this natural landscape. Dikes and dams have appeared, polders and reclaimed land have been built, peat was extracted and land use has become increasingly intensive. Nevertheless, that natural genesis still manifests itself in the subsoil of the area. It is reflected in the existing soil types, the differences in elevation or landscape patterns that testify to that dynamic estuary. Although important abiotic processes have disappeared (the sea influence) or decreased in intensity, wind, discharge differences of rivers and streams and groundwater flow still play key ecological roles. Or these processes can be restored or intensified again. In this respect, enlarging of and improving conditions in existing N2000 reserves, developing new nature areas and specific management aimed at restoring ecological gradients and natural differentiation are essential. The original estuary of the IJssel and Vecht deltas vanished. But the dynamic transitional environments of lakes, rivers, gullies and swamps - here referred to as gradient swamps of the inland delta - are on a drip, waiting for resuscitation. This report describes the first steps in this direction.