Figure 1 . Influence of rainfall on channel profile form and topographic metrics at steady state. a) Top row – left panel shows river profiles adjusted to different amounts of spatially uniform rainfall. Corresponding discharge accumulation curves are shown in the middle panel. Right panel shows the relationship between mean rainfall (defined as Q /A ) calculated at the outlet, with fluvial relief (R ), ksn , andksn-q for a fixed uniform rock uplift rate. Note, at steady state fluvial relief and ksn are inversely related to mean rainfall, while ksn-qis independent of changes in rainfall. b) Bottom row – all panels as in (a) but for a comparable suite of steady-state profiles adjusted to spatially uniform rainfall, a decreasing upstream rainfall (bottom-heavy) pattern, and an increasing upstream (top-heavy) pattern. Note intersections that occur between profiles in the left panel and middle panels, and that fluvial relief and ksnare positively related to mean rainfall in these cases (right panel), inverted from (a). All other model parameters are equal (see Table 1).