Fractal analysis is useful for studying complex fluctuation phenomena that exhibit scaling behavior. In this work, fractal analysis is used to characterize transient dynamics of gravity-driven surface granular flow down inclined plane. Intensity fluctuation of light scattered from granular flow is modelled by multifractional Brownian motion with time-varying Hurst exponent. Temporal variations in the Hurst exponents over the time-development of flow are analyzed for different particle sizes and opening sizes of the hopper.