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OpenHydrology / StatisticalFloodEstimationTool

wxpython based tool for assessing flood flows using current UK FEH methods
GNU General Public License v3.0
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correct uk and ire grid issue #17

Open neilnutt opened 10 years ago

neilnutt commented 10 years ago

Currently no recognition of different grids when calculating distances

faph commented 10 years ago

The cd3-parser I'm currently preparing takes this into account by setting catchment.country to either gb or ni. Centroid coordinates will be a (E, N) tuple. Distance calcs could then simply discard or set to infinity when catchment1.country != catchment2.country.

neilnutt commented 10 years ago

Good, at least it wont do the wrong thing. I would still like to come back to it one day, I reckon it wouldn't be too hard to transform ni grid references into GB grid references.

faph commented 10 years ago

Not sure if you ever need the distance across different countries. For QMED adjustment, it's purely distance based (ie within country) and for pooling group it's purely hydrological similarity (ie inter-country, don't care about distance). Correct?

neilnutt commented 10 years ago

Working with catchments in ni can be a bit limiting without it. Also useful for catchments in around Ayrshire.

If you follow the official guidance you are right for pooling, however geographic proximity is important for sepa and I partly agree it shouldn't be overlooked (within reason). Something quite high on my todo list is to allow the user to form their own 'hydrological distance function' for forming pooling groups. Probably a feature just for Scotland, but might also a consistent approach for dealing with catchments with differing bfi where it seems to be a random decision by the person doing the calc. Looking ahead it might be a function that sepa would like enough to suggest it ad their preference over other software products. On 6 Sep 2014 01:33, "Florenz A.P. Hollebrandse" notifications@github.com wrote:

Not sure if you ever need the distance across different countries. For QMED adjustment, it's purely distance based (ie within country) and for pooling group it's purely hydrological similarity (ie inter-country, don't care about distance). Correct?

— Reply to this email directly or view it on GitHub https://github.com/OpenHydrology/StatisticalFloodEstimationTool/issues/17#issuecomment-54696788 .