It could kill them
according to the flood history in the book of Genesis, only 8 survived that.
malaria
they didn't at all
No
they affect harvesting and the flood.
a flood is when there is an overflow of water, burst pipe..........etcetcetc................, you can see other answers as well for floods that can affect people if you want to see floods, go onto google images and type in "Flooding" it comes up with some amazing pictures.......
Water everywhere
They can raise the sea levels and permanently flood coastal cities and croplands.
The flood deposited silt in the farming fields which provided fertilizer. Once the flood waters receded the fields were ready to plant.
flood kill the people .
Rivers can flood (overflow their banks) destroying homes, crops, cars and all kinds of things