Soil–Sediment–River Connections: Catchment Processes Delivering Pressures to River Catchments

This chapter presents and discusses the soil–sediment–river connections and summarises the pressures at the basin scale from their causes (natural and anthropogenic drivers) to their consequences (impacts on biophysical status). Nine important pressures on river basins are evidenced with respect to their temporal and spatial scale of occurrence and their impact on the river basin at the basin scale and concerns: erosion, sealing, compaction, hydromorphological changes, salinisation, contamination, changes in water quantity, acidification and reduction of soil organic matter. Each pressure can affect the biophysical status, and the simultaneous presence of pressures can have cumulative or compensatory impacts on biophysical status through propagation. Eight biophysical statuses were identified (concentration of chemicals, trophic status, biota status, buffering capacity, salinity, suspended matter and sediment, water level, morphology and pedology), and the pressures are described in this chapter in the sense of impacts on these biophysical status.