Modelling of potential effects of long-term fluvial dynamics on possible geological storage facilities of nuclear waste in the Netherlands

Abstract

Within the programme of investigation for suitable safe geological sites (such as salt diapirs) for long-term storage of radioactive waste (OPLA), a modelling study of long-term effects of fluvial dynamics was carried out. The model used, FLUVER, allows long-term simulations of the combined effects of climatic change, tectonism, sea level and initial relief on fluvial erosion. As an exercise, landscape development scenarios of a Rhine-Meuse type system with climate and base-level dynamics related to Milankovitch's astronomical theory, during stable, uplifting, and subsiding tectonic scenarios, are simulated and discussed. Under the assumptions that climate and base-level changes can be described with Milankovitch's theory and that tectonic activity in the Netherlands will not change considerably during the next hundred thousands of years, it can be concluded provisionally that the maximum fluvial erosion depth in the next few hundred thousand years is unlikely to exceed 100 metres and to reach a salt diapir.