Hamilton type gradient estimates for a general type of nonlinear parabolic equations on Riemannian manifolds

$ (\Delta_{V}-q(x, t)-\partial_{t})u(x, t) = A(u(x, t)) $ on complete Riemannian manifold (with fixed metric). When $ V = 0 $ and the metric evolves under the geometric flow, we also derive some Hamilton type gradient estimates. Finally, as applications, we obtain some Liouville type theorems of some specific parabolic equations