Perhaps the water should be measured by mass. We know 1 mm on 1 m² is a millitonne, so on a hectare, 10 t would be required. :)
________________________________ From: Pat Naughtin <pat.naugh...@metricationmatters.com> To: U.S. Metric Association <usma@colostate.edu> Sent: Fri, June 11, 2010 9:13:38 PM Subject: [USMA:47729] Re: Volume in metric On 2010/06/12, at 01:14 , Phil Hall wrote: These remarks are prompted by the "Oil spill" thread which lead to a discussion on units of volume. > >The litre (or liter of you prefer) has, IMHO, a lot going for it as a general >purpose unit for most ranges. Its main advantage is the avoidance of the >superscripted 3 for plain text messaging. It is also easily converted to cubic >metres when that is required (just divide by 1000). I have to say I don't like >the dam³ that has been suggested. I don't see why the megalitre or ML won't do >just as well. > >We then have: > >1 m³ = 1 kL >1 dam³ = 1 ML >1 hm³ = 1 GL >1 km³ = 1 TL > >Simple yes? > Dear Phil, Having lived in a society where most of us very successfully use this small set of units for all of our everyday tasks: 1000 millilitres = 1 litre 1000 L = 1 cubic metre 100 grams = 1 kilogram 1000 kilograms = 1 tonne 1000 millimetres = 1 metre 1000 metres = 1 kilometre I find it hard to agree that it would be a good idea to introduce the dam³, the hm³, and the km³ to Australians for everyday use. In the specialist area of farming, and especially of irrigation farming, the metric system units, kilolitre, megalitre and gigalitre, have served us well. This is especially true for farm water calculations. You know the basic rule: one millimetre of rain on a 1 square metre surface supplies a litre of water. Farmers expand this to 1 millimetre of rain on one hectare provides 10 000 litres (10 kL) of water. It follows that (say) 200 millimetres of irrigation water needed for a vegetable crop on one hectare of land will need 3 000 000 litres of water (300 millimetres x 10 000 litres); which would be ordered from the irrigation water supplier as 3 megalitres. By the way, you might not have seen this curious unit used by Australian farmers and graziers: kilograms per millimetre-hectare (kg/mm.ha). This is used to compare two pieces of farming land that have different rainfall. As an example for cattle grazing a property might produce 800 kilograms of beef from each hectare from a farm where 540 millimetres of rain falls in a particular year. Cheers, Pat Naughtin Author of the ebook, Metrication Leaders Guide, see http://metricationmatters.com/MetricationLeadersGuideInfo.html Hear Pat speak at: http://www.youtube.com/watch?v=_lshRAPvPZY PO Box 305 Belmont 3216, Geelong, Australia Phone: 61 3 5241 2008 Metric system consultant, writer, and speaker, Pat Naughtin, has helped thousands of people and hundreds of companies upgrade to the modern metric system smoothly, quickly, and so economically that they now save thousands each year when buying, processing, or selling for their businesses. Pat provides services and resources for many different trades, crafts, and professions for commercial, industrial and government metrication leaders in Asia, Europe, and in the USA. Pat's clients include the Australian Government, Google, NASA, NIST, and the metric associations of Canada, the UK, and the USA. See http://www.metricationmatters.com/ to subscribe.
