We consider the Cauchy
problem for hyperbolic geometric flow equations introduced recently by Kong and Liu
motivated by the Einstein equation and Hamilton Ricci flow, and obtain a necessary
and sufficient condition for the global existence of classical solutions to this kind of
flow on Riemann surfaces. The results show that the scalar curvature of the solution
metric gij converges to one of flat curvature, and the hyperbolic geometric flow has
the advantage that the surgery technique may be replaced by choosing a suitable
initial velocity tensor.