River drainage basins are the powerhouses for the particulate and dissolved fluxes of sediment routing systems. Drainage basin size follows a power law. Continents differ from each other in the size distribution and topological order of drainage basins. Active (convergent) plate margins have small, short, steep catchments compared to the large, low-gradient catchments of passive continental margins. Fluxes of particulate and dissolved loads are driven by run-off of precipitation. Particulate fluxes to the ocean are an indication of erosion rates in contributing catchments, but large amounts of sediment may be sequestered in alluvial floodplains and channels. Sediment yields are influenced by a range of totpographic factors including elevation and slope, climatic factors such as precpitation rate, temperature and vegetation, and tectonic factors such as uplift rate of rock. Solute fluxes are strongly dependent on bedrock type undergoing weathering and the availability of precipitation to flush regolith of solutes. Carbonates and evaporites release high amounts of total dissolved solids.