Initial screening results from new calibrated model

As discussed the simulated hydrograph produced by the calibrated model shows a much better fit with the observed hydrograph from the 2000 flood event. In a few weeks (thousands of simulations takes quite a while) I'll be able to show more results on the uncertainty associated with the new calibrated model.

For now here are the initial screening results, similar to those presented a while ago for the old model.

A key aspect is the effect of placing a CRIM at one reach is greatly reduced. No reaches individually reduce flow peak by over 4 cumecs, as opposed to around 10 (depending on the time map used) which reduced peak flow by >5 cumecs with the old model.

One explanation for this is that the simulated peak discharge is more accurate and also lower. Therefore even if the CRIMs were still having the same effect in terms of % reduction of the initial flow peak, the reduction would be less.



Importantly, from initial work with combinations of reaches, it appears that in combination the reaches have less of a reducing effect on peak flow than the sum of their parts. For example, as a simplification, two CRIM sites which on their own reduce simulated peak flow by 3 cumecs each may in combination only reduce peak flow by around 4 cumecs.

These results will be discussed in more depth soon