Extreme Flood Sediment Production and Export Controlled by Reach‐Scale Morphology

Rapid earth surface evolution is discrete in nature, with short-duration extreme events having a widespread impact on landscapes despite occurring relatively infrequently. Here, we exploit unique opportunity to identify the broad, process-based, controls sediment production and export during rainfall-runoff through multi-catchment analysis. A 3 hr rainfall event generated significantly different impacts across three catchments, ranging from (a) exceeding two orders of magnitude more than typical long term average (b) minimal impact, this variability primarily controlled by catchment steepness presence reach-scale morphological transitions caused postglacial landscape adjustment. In any worldwide where populations are at risk, highlight importance combining topographic analysis detailed mapping channel bed material (e.g., between process domains) identification sources within transition zones for accurately predicting events.