How do I establish how many litres per minute are flowing through the main irrigation line?
You should have already worked out the size of the area being supplied by the watering station in step three. Multiply this area by the depth of water you got from your catch cups in step one. This will give you the total amount of water flowing through the irrigation line in cubic metres. There are 1000 litres in one cubic metre so you will then need to multiply cubic litres by 1000 to find litres per minute.
e.g. If the area you are watering is 4000 square metres and your catch cups caught 5 mm of water in 30 minutes then:
4000 square metres x 0.005 metres = 20 cubic metres
There are 1000 litres in a cubic metre so:
20 cubic metres x 1000 litres = 20000 litres in 30 minutes
|
Litres/minute = |
20000 |
 |
|
|
|
30 |
= 666 litres per minute.
