General control of uplift gradients and rock erodibility in formation and evolution of main drainage divides

Main drainage divides play a crucial role in the landscape development; however, the influencing factors on their initial formation and subsequent development are still subjects of ongoing debate. Gaining insight into how these prominent features originate is essential for achieving a better understanding of their evolution. We employ landscape evolution modelling to simulate the formation of main drainage divides on uplift ramps, i.e., uplift gradients, which are commonly found at different tectonically active settings. We evaluate how uplift gradients of different magnitudes across a same mountain width interact with different rock erodibilities to initiate and develop main drainage divides. Results indicate that the propagation of main drainage divides and the growth of their topography exhibit an asymptotic behavior with different amplitudes over time. Moreover, we find that variability on uplift rates and rock erodibility generates systematic differences in elevation. • Resistant rocks and moderate uplift produce prominent main drainage divides. • Main drainage divides reach an elevation threshold once they are consolidated. • Sinuosity of main drainage divides has prevailing oscillations over time.