The detailed analysis of the stream-long profiles of two river basins within the Rio Piura catchment reveals a distinct knickzone in the transition zone between the easterly and westerly climatic influences, suggesting an En Nixf1;o forcing on the longitudinal channel profiles over at least Holocene timescales. Measured trunk stream catchment-wide denudation rates are up to ca. 300 mm ky− 1 and decrease successively downstream along the river profiles. Denudation rates of tributary rivers are ca. 200 mm ky− 1 near the plateau and show a stronger downstream decreasing trend than trunk stream rates. This suggests that the landscape is in a transient stage of local relief growth, which is driven by fluvial incision. This corroborates the results of paleoclimate studies that point towards higher El Nino frequencies during the past ca. 3000 years, leading to higher runoff and more erosion in the trunk channel compared to the hillslopes and thus growth of local relief. Downstream increases in channel gradient spatially coincide with the reaches of highest precipitation rates during El Nixf1;o events, we therefore interpret that Holocene landscape evolution has largely been controlled by climate. The ky-timescale of the 10Be data together with the transience of the landscape implies that El Nixf1;o events in northwestern Peru have occurred since at least the Holocene, and that adjustment to channel incision is still taking place.