Advantages and dis advantages of liviing in a floodlain?

Answer 1

Land in floodplains tends to be richer and more fertile. The cost of that is that, well, sometimes it's flooded. This may happen either rarely, or with seasonal regularity (the Nile, for example, historically flooded at certain times of year). If it's a regular flood it may be possible to plan around it; if it's more random, that means that some years you may lose your crops.

This is an advantage/disadvantage to FARMING in a flood plain. There really is no advantage to LIVING in a flood plain, unless it's not possible to live near your farm without living in the flood plain itself, or you just really like having your home flooded. In some cases the tradeoff of living in an occasional flood plain may be worth it; land there may be cheaper, for example. In real estate and insurance there's a concept called a "100 year flood plain" (or some other time span), which basically means that, historically speaking, once in every 100 years (or however long) that area has been flooded. Living in such an area then becomes a calculated risk, and you have to decide if you're willing to gamble on the odds breaking in your favor to be able to take advantage of land price/availability/convenience (if you have an occupation that depends on proximity to a river).