DISTURBED PRESSURE DISTRIBUTION ALONG SLIGHTLY CURVED BANKLINE BASED ON SMALL-DISTURBANCE THEORY

In order to reveal the discipline and the main influence factor of disturbed pressure distribution along sinuous bankline, the small disturbance theory was used to linearize the 2D shallow water equations and the boundary conditions. Analytic expressions of disturbed pressure along sinusoidal curved bankline had been derived. A sensitivity analysis of influence factors was also presented. The pressure expressions and sensitivity analysis show that the disturbed pressure along the slightly curved bankline follows sinusoidal distribution. The crest and trough values of disturbed pressure appear at the maximum curvature locations of concave and convex bank, respectively. The bank amplitude-to-wavelength ratio a/λ is found to be the main factor of pressure variation in subcritical flow. The derived results can be used to estimate the boundary condition of stream-subsurface exchange in riparian zones, which is helpful to the further study on lateral hyporheic exchange and hydrodynamics in riparian areas.