Matt_M
8th November 2013, 04:37 PM
Ok, been thinking about something.
I have a rain gauge in the veggie garden.
It takes a lot of rain to fill this to 5mm or 100mm or whatever, yet only takes a few seconds with the hose pipe nozzle.
Does this mean that when I have the hose nozzle on the veggie bed for say 60 seconds, that is the same as approx 2 days of solid rain ?
Can you get my situation, I am prepared for smart ass answers :D :D
Gardner Matt :p
Wrongwayfirst
8th November 2013, 06:51 PM
Here goes,
your rain guage measures rainfall in mm over a set area, usually 1 metre square, over time.
so 1mm of rainfall is 1mm deep on an area 1000mm x 1000mm = 1 litre of water, over time i.e.1 hour or 24 hours. Weather forecast is always 24 hour period 9AM to 9AM, your rain guage can be whatever interval you like, people will often say we had 25mm of rain in 1 hour. If they had no more rain that day the weather station would report 25mm of rainfall for the 24 hour period.
most rain gauges probably measure no more than 250mm of rainfall and would hold about 2 litres of water.
your garden hose will flow in the vicinity of 20 litres per minute so will fill the rain guage in about 6 seconds.
so you have in effect watered an area equivalent to the opening of your rain guage with 2mm of rainfall in 6 seconds. Generally approx 10mm of rainfall per day on your veggies will keep them alive, so a 30 second hosing of your rain guage is an appropriate "rainfall" to keep your veggies alive.
calculate the area of your rain guage opening and that opening area multiplied over the area of your garden bed multiplied by 30 seconds will tell you how long you have to hold the hose to water your patch and given most people can drink a beer in 5 minutes (or 10 x the area of your rain guage opening) will lead to the fact that you always run out of beer before the garden is fully watered.
Hope this helps, cheers