Uncovering the Controls on Fluvial Bedrock Erodibility and Knickpoint Expression: A High?Resolution Comparison of Bedrock Properties Between Knickpoints and Non?Knickpoint Reaches

Bedrock erodibility exerts a fundamental control on fluvial incision, and therefore the evolution of entire landscapes. However, roles relative significance specific bedrock properties like rock strength discontinuity spacing in setting remain poorly understood. As result, is often overlooked or oversimplified numerical field-based investigations landscape processes, leading to misinterpretation channel profile convexities (i.e., knickpoints) studies seeking infer uplift baselevel histories from longitudinal analyses. Here, we investigate controls knickpoint expression by conducting detailed surveys 21 lithologic knickpoints non-knickpoint reaches (representing end-member cases) corresponding small channels south-central Appalachian Mountains. We use binary logistic regression field data test as predictors occurrence, their impact erodibility. find that more strongly influences this setting, where both vary widely, confirming for first time quantitatively hypothesis discontinuities exert dominant also unique given stratigraphic interval, implying morphology intimately linked local conditions effectively unpredictable without measurements. Finally, because all our study occur within single geologic unit, results illustrate intra-unit heterogeneity must be accounted when considering influence convexities.