Official World Meteorological Organization (WMO) guidance for rainfall specifies it to be given in millimeters. So the use of volume per unit area must be old practice that is hard to overcome.
Don > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf > Of Tom Wade > Sent: Wednesday, 2005 October 26 07:05 > To: U.S. Metric Association > Subject: [USMA:35006] Re: Rain measurement in Europe > > Harry Wyeth wrote: > > I recently returned from Spain, where I viewed a TV news program about > > flooding in part of that country. The reporter stated that the rainfall > > had been in the amount of 8.-something liters per square meter within a > > one hour period. > > > > Anyone have any idea why she made it so complicated? Why not just say > > rainfall in the amount of 8.xx cm, period? Is this a European thing? > > I have heard that this practice is common in Europe, although in Ireland, > rainfall is quoted in mm (probably because it used to be quoted in > inches). However, mm of rainfall (not cm) and liters > per square meter actually comes to the same thing, 8.6 mm of rain is > actually 8.6 L/m². > > See http://www.fao.org/docrep/R4082E/r4082e05.htm > > As for the why, I agree with you. Although the formal units used are > more correct (how can you measure a liquid as a length?) and therefore > to be preferred in a scientific article, the use of mm is more intuitive > to the TV viewer, as he can visualize the amount of rain needed to produce > flooding that deep. > > --------------------------------------------------------- > Tom Wade | EMail: tee dot wade at eurokom dot ie > EuroKom | Tel: +353 (1) 296-9696 > A2, Nutgrove Office Park | Fax: +353 (1) 296-9697 > Rathfarnham | Disclaimer: This is not a disclaimer > Dublin 14 | Tip: "Friends don't let friends do Unix !" > Ireland > > >
