Quantification of the impact of pre-historic land use on suspended sediment accumulation in the Rhine delta

Abstract

Deltaic sedimentation is facilitated by sea-level rise and tectonics, but most importantly is the result of the sediment input by the rivers. The architecture of the Holocene Rhine delta in the Netherlands ( 3000 km2) is well documented and the provision of accommodation space by sea level rise and tectonics well quantified. Using budget analysis, we have now also independently quantified the amounts of sediment input and storage in the delta. This provides much wanted quantitative understanding of the sediment delivery history from the Rhine catchment ( 185,000 km2), which has a relative long history of human deforestation, from the Neolithic ( 6 ka BP) onwards. We developed a method that utilizes the extensive geological datasets available for the Rhine delta (boreholes, dates, stratigraphical cross-sections, palaeogeographic maps). In the sediment storage budgeting for successive 500-yr time slices spanning the last 9000 years, we included quantification of internal reworking. We split the analysis over 11 subsegments of the delta and 6 facies-associations.