Rates of land surface processes provide insights into climate and
tectonic influences on landscape dynamics. River incision rates into
bedrock are estimated by dating perched landforms such as strath
terraces, assuming a constant bedrock incision rate from terrace
abandonment to present. These estimates express biases from the
stochastic nature of river incision and from using a mobile channel
elevation as a reference frame. No existing mechanistic framework fully
addresses these biases. We introduce a 1-D river evolution model
incorporating fluvial mechanics, sediment dynamics, tectonics, and
climatic factors to predict these biases and assess their sensitivity to
climate and rock-uplift rate. Findings suggest biases intensify under
highly variable climates and slow rock uplift, with the period of
climate being a primary control. Our model improves river incision
measurement reliability, impacting paleoclimate and tectonic
geomorphology reconstructions.