Where can I build Irrigation Canals?

[duirixuanyan]

It says," requires pop 6, non-Arid" . Can I build it on rough terrian?

By the way, the unique Carthaginian building "Temple to Ba'al Hammon" Token chance reduction 15%. If I build 3 Temple to Ba'al Hammon, does it mean I won't get or lose any token any more?

[poesel71]

Any bonus/reduction in this game is not added but multiplied.

So iyou have a 30% chance for a token and it is modified by -15%. The modification is 15% of 30% = 4,5%. The resulting percentage is 25,5% and not 15%.
I guess(!) that multiple temples are applied to the reduced chance so you have diminishing returns and you can never get to 0%. Please correct me if I'm wrong here.

[duirixuanyan]

Any bonus/reduction in this game is not added but multiplied.

Is it true?