Effects of Land‐Use and Precipitation Changes on Floodplain Sedimentation in the Nineteenth and Twentieth Centuries (Geul River, The Netherlands)

Abstract

flowing through France, Belgium and The Netherlands; Fig. 1a) flooded severely, causing extensive damage and forcing massive evacuations. These events sparked an interest in land-use and climate change as possible causes of the recent, apparent increase in flood frequency. To separate the effects of land-use change and precipitation variability on the peak discharges of the Meuse, one would ideally need single cause-effect relationships for discrete time periods and a long discharge time-series. For a river basin such as the Meuse (33 000 km 2 ) there are no such undisturbed cause-effect relationships, because it is used for international commercial shipping and various other economic purposes, and therefore has been heavily engineered. Generally, peak discharges in the Meuse lead to flooding problems when peak discharges in subcatchments such as the Ourthe and the Sambre (Fig. 1a) coincide with those of the main channel Effects of land-use and precipitation changes on floodplain sedimentation in the nineteenth and twentieth centuries (Geul River, ABSTRACTThe effects of land-use change and precipitation variability on the flow regime and sedimentation rates of floodplain deposits were studied in the Geul River in the southern part of The Netherlands. The catchment has a history of industrial mining, thus providing a means for dating the sediment. Several cut-bank sections were analysed for grain size, organic matter, Zn, Pb and 137 Cs, and sedimentation rates were calculated for the periods 1806-1845, 1845-1885, 1885-1955 and 1955-1996. Sedimentation rates were high between 1806 and 1885, very low between 1885 and 1955, and high again between 1955 and 1996. Rates of channel change derived from the analysis of aerial photographs show an increase after 1949 and 1981. Comparison with precipitation and land-use data indicates that the high sedimentation rates in the nineteenth century were caused by mining activities and deforestation, resulting in more floods in the low-magnitude-high-frequency range. The termination of industrial mining around 1885, subsequent reforestation, and the agricultural crisis of 1878-1895 all contributed to the low river activity during the first half of the twentieth century. The modernization of agriculture and increased precipitation have contributed to an increase in sedimentation rate and channel-change rate during the second half of the twentieth century. Increased soil erosion associated with the modernization of agriculture is an important new source of sediment.

Fluvial architecture of Belgian river systems in contrasting environments: implications for reconstructing the sedimentation history

“…5), causing severe contamination of fluvial deposits. Previous studies (Stam, 1999(Stam, , 2002 have shown that peaks in heavy metal concentrations in fluvial deposits can be linked with peaks in 19 th century mining activities. Where previous studies focused on profiles at cutbanks, we sampled within the alluvial plain to get a better spatial distribution of sampling sites over the floodplain.…”

“…Additional age control is derived if the temporal variations in tracer introductions are known, as these can be linked to tracer concentrations in the floodplain deposits (e.g. Stam, 1999Stam, , 2002.…”

Estratigrafia y sedimentologia del abanico terminal de la Formacion Candeleros (Grupo Neuquen), Cretácico Inferior, Cuenca Neuquina, provincias de Neuquen y Mendoza, Argentina.

“…It is expected that less significant and higher frequency flood flows including those in which channels run from bank to bank, impose their own record on the channel (Stam, 2002). The cycles of recurrent flooding in this area of the basin generated a thick sequence with typical deposits produced by ephemeral streams in sheet flood events and the absence of clay-size components in the flood environments.…”

Concepts of dynamic equilibrium of interest for river management in the lower Maas catchment

“…In this perspective, it is our objective to provide in this paper a framework for a better understanding of frequency and magnitude of flooding, and thus help in river management. As a case study, we deal with the lower Maas River valley and one of its main tributaries in The Netherlands, the Geul River (Stam, 2002;De Moor, 2006; for location see Fig. 1).…”