Interaction between tectonics and climate encoded in the planform
geometry of stream networks on the eastern Tibetan Plateau
Stream networks are highly abundant across Earth’s surface, reflecting
the tectonic and climatic history under which they have developed.
Recent studies suggest that branching angles are strongly correlated
with climatic aridity. However, the impact of tectonic forcing,
especially in tectonically active regions, remains ambiguous. Here we
analyze the branching angles of major stream networks on the eastern
Tibetan Plateau, a region with complex tectonics, variable climate, and
diverse landscapes. We find that spatial variations in tectonic uplift
(as reflected in channel gradients) shape the branching geometry of
stream networks on the steep eastern margin while in the flat interior
of the eastern Tibetan Plateau, branching angles are mainly controlled
by climatic aridity. This leads to the conclusion that, in the steep
margin of the eastern Tibetan Plateau, climatic impacts on branching
angles are overprinted by stronger tectonic controls.