No abstract

This paper aims to explore the temporal-spatial spreading and asymptotic behaviors of West Nile virus (WNv) by a reaction-advection-diffusion system with free boundaries, especially considering the impact of advection term on the extinction and persistence of West Nile virus. We define the spatial-temporal risk index R F 0 (t) with the advection rate (µ) and the general basic disease reproduction number R D 0 to get the vanishing-spreading dichotomy regimes of West Nile virus. We show that there exists a threshold value µ * of the advection rate, and obtain the threshold results of µ * . When the spreading occurs, we investigate the asymptotic dynamical behaviors of the solution in the long run and first give a sharper estimate that the asymptotic spreading speed of the leftward front is less than the rightward front in the case of 0 < µ < µ * . At last, we give some numerical simulations to identify the significant effects of the advection.