摘要

In this paper, we consider a space fractional advection-dispersion equation. The equation is obtained from the standard advection-diffusion equation by replacing the first-and second-order space derivatives by the Riesz fractional derivatives of order beta(1) is an element of(0, 1) and beta(2) is an element of(1, 2], respectively. The fractional advection and dispersion terms are approximated by using two fractional centred difference schemes. A new weighted Riesz fractional finite-difference approximation scheme is proposed. When the weighting factor theta equals 1/2, a second-order accuracy scheme is obtained. The stability, consistency and convergence of the numerical approximation scheme are discussed. A numerical example is given to show that the numerical results are in good agreement with our theoretical analysis.