In order to identify a short list of options from the long list of options shown in Table 1, we have undertaken ‘top down’ and ‘bottom up’ modelling analysis. ‘Top down’ analysis involves using historical patterns of estuary changes to predict what might happen in the future. ‘Bottom up’ analysis involves using a computer model built on the existing conditions in the estuary which is used to predict what will happen in the future under each option.
These modelling techniques have been used to identify how each option will affect the whole estuary under present conditions and scenarios of Sea Level Rise and Tidal Surges (like the 1953 flood event). This is done by considering how an option affects the following: