Don't think it's possible to have so much food reserves. I don't
think it's possible, because food will spoil if kept too
long.
Arbitarily, let's say 1 person consume 0.25kg of rice a day.
One year he will consume 0.2kg X 365 days = 91.25kg.
4 million singapore will consume:
4,000,000 X 91.25kg = 365,000,000 kg/ year
For 2 years:
365,000,000 kg X 2 years = 730,000,000 kg for 2 years
You know those huge containers at PSA, the big 40 ft container
holds 26,680 kg.
http://www.geseaco.com/GESeaCo/ContainerFleet/DryFreightBoxes/
You would need:
730,000,000 kg / 26,680 kg/container = 27,361 containers.
Think you need a volume the size of 27,361 containers to hold
everything.