Sinuosity-Driven Water Pressure Distribution on Slope of Slightly-Curved Riparian Zone: Analytical Solution Based on Small-disturbance Theory and Comparison to Experiments

Abstract

A curved riparian zone can create highly complex flow patterns that have a great effect on erosion, pollutant transport, surface water-groundwater exchange and habitat qualities. The small-disturbance theory has been applied to derive the analytical solutions of pressure distributions along a sinusoidal riverbank. Experiments have also been performed to test the hydrodynamic and geomorphic effects on pressure distribution and to verify the applicability of the derived expressions. The derived expressions were simple, accurate and agreed remarkably well with experimental results for the riparian banks with a low degree of curvature. On the contrary, when a riparian bank had a high degree of curvature, these expressions applying the approach of small-disturbance, could not effectively estimate the pressure distributions for a complex bank boundary or complex flow conditions. Moreover, sensitive analysis has indicated that the disturbed pressures along the riparian banks increased with increasing Froude number Fr, as well as the ratio of bank amplitude to wavelength a/λ. However, a/λ has been found to have more significant influence on pressure variation in subcritical flow.

Observing and modelling dynamic changes in temperature and volumetric fluxes within a riverbank aquifer under the influence of seasonal river stage fluctuations

“…Molina-Giraldo et al (2011) found that the saturated aquifer in the riparian zone was significantly affected by the heat transfer in the unsaturated zone by establishing a riparian flow-heat coupling model. Xia et al (2016) applied the theory of small disturbance to establish the distribution equation and analytical solution of the disturbance pressure caused by the curved shape of the river bank and explored the mechanisms of lateral hyporheic exchange in the homogeneous microbend riparian zone.…”