  We introduce a definition of finite-time curvature evolution along with our
recent study on shape coherence in nonautonomous dynamical systems. Comparing
to slow evolving curvature preserving the shape, large curvature growth points
reveal the dramatic change on shape such as the folding behaviors in a system.
The level curves of the finite-time curvature evolution field indicate the
existence of shape coherent sets.

Dynamical Systems