Lough Erne water levels ? ( for Alun )
Quelle IWAI, Kommentar von Admin
Lieber Leser,
Hier die wesentlichen Ausagen als Zitat von diesem Beitrag (Alun):
The levels the voice announcer gives out are in metres above sea level, which in this case is a mark on the base of Poolbeg lighthouse, in Dublin Bay. This is known as the datum, a level deemed to be 0m. Sea level in other words.
(= OD)
There are two other datums in use in Ireland, which are Malin in the ROI and Belfast in NI. Both are markedly different to Poolbeg at around 3m different, but although close, Malin and Belfast are not the same. Also, the satellites are uploaded every twenty minutes or so with reference levels from the ground.
Is there a usual level? No, there are ranges within which we try to work. Legally, the Lower Lough has to be between 44.80m (146,98 Fuß) & 46.32m (151,96 Fuß). The Upper Lough is not to fall below 45.72m (150 Fuß) and should not, as far as can be reasonably prevented, rise above 46.92m (153,93 Fuß) summer (Apr to Sept inclusive) or 47.32m winter (Oct to Mar incl). In practice, we try to work within 45.32 and 45.98 on the Lower Lough, but during the summer within 45.72 (150 Fuß) to 45.98 (150,85 Fuß). Not always possible.
The Upper Lough is much more variable; the vast bulk of the catchment flows into the Upper Lough and all this has to pass through Enniskillen. However, we will always maintain the minimum of 45.72. In a dry summer such as we've just had there is an argument that the minimum isn't high enough for modern boats, ie TSDYs etc as its quite shallow in a lot of the Upper Lough; on the other hand, the farming community would want it 600mm lower. That would make the Upper Lough inaccessible to virtually all boats except lake boats and dinghys. The flood plain created if that were to happen would simply flood every time it rained, and then the call would go up for it to be lowered another 600mm.Ende Zitat (Alun).
LLE = 150-151'
ULE = 150-154'
Lough Erne water levels ? ( for Alun )
