Hydrological and hydraulic modelling of the Nyl River floodplain. Part 2: Modelling hydraulic behaviour

Abstract

Catchment land-use and water resource developments may threaten the ecological integrity of the Nyl River floodplain, a world-renowned conservation area. The effect of developments on the water supply regime to the floodplain can be pre dicted by hydrological modelling, but assessing their ecological consequences requires transformation of discharge into eco logically-relevant hydraulic characteristics. Studies of Wild Rice ( Oryza longistaminata ) have indicated that the important variables are the extent, depth, duration and timing of flood inundations. One-dimensional hydraulic modelling has been successfully applied to predict these flood characteristics, using a suite of models comprising Quicksurf, RiverCAD, HEC-RAS and HEC-DSSVue. Separate but linked models were developed for three contiguous portions of the large floodplain. The topography was surveyed by airborne laser mapping, and extensive discharge, water level, rainfall, infiltration and eva potranspiration data were collected for model calibration and verification.

Authors

Categories