Development of a revised desktop model for the determination of the ecological reserve for rivers

The previous version of the Reserve Desktop model was based on hydrology and regional parameters, which were largely based on seasonal distributions of stream flow. A recent development in EWR methodology is the flow stressor response method, which links the hydraulic habitat requirements of biota, to the hydraulic characteristics of a channel cross-section, to specify the ecological stress conditions that will occur under different flow regimes. Components of the model deal with hydrology, hydraulics and ecological requirements. The hydraulic sub-model uses a desktop approach to define the characteristics of a representative channel cross-section in the absence of detailed field surveys. The ecological requirements of fish are based on the Velocity Depth Guild (VDG), an approach developed to interpret ecological consequences from generic information on the stream width.