CASSIE CoRe ®

Hydro (Requirements Gathering)

(Empirical estimation of hydrodynamic flow velocity in estuaries) 

Hydromorphological data for many estuaries around the world are scarce and generally limited to offshore tidal ranges and satellite imagery. In many projects, information on morphology and intertidal area is needed to assess the effects of human interventions and sea level rise on natural depth distribution and habitat change.

Habitat area depends on the spatial pattern of the intertidal area, flood timing, peak flow velocities, and salinity. Although numerical models can reproduce these spatial patterns reasonably well, their data requirements and computational costs are high and, for each case, a new model must be developed. Here, we propose to integrate into the CASSIE-CoRe ® web platform the tool developed in JavaScript, by Leuven et al. (2018,<https://doi.org/10.3390/rs10121915>) which includes a comprehensive set of relationships that predict the hydrodynamics, morphology and patterns of the channel and banks online in a few seconds. The predictions are based on a combination of empirical relationships derived from natural estuaries, including a new predictor for cross-sectional depth distributions, which is dependent on the width profile along the channel (Leuven et al., 2018,).

Flow speed, an important habitat characteristic, is calculated with a correlation between depth below water level and maximum tidal flow speed, which should be based on spatial numerical modeling (Leuven et al., 2018). The tool will only require a channel width profile and tidal range, making it useful for quick assessments when only satellite imagery is available (Leuven et al., 2018).