They had 'ways'
They are opposites to each other. A drought is no water, but a flood is too much.
The opposite of a flood would be a drought.
a drought
A flood after a drought can lead to rapid runoff due to dry, compacted soil that is less able to absorb water, increasing the risk of erosion, mudslides, and debris flow. The sudden influx of water can also damage crops, disrupt ecosystems, and exacerbate flood damage due to decreased vegetation cover from the drought.
Drought.
Flood
a flood happens when there is a drought then it rains a lot then it creates a floof that makes a flood
They really did not predict - they just realised that it happened at the same period each year.
flood
A drought is a prolonged period without rain. The opposite would be a deluge, or a flood.
Drought or shortage
because they are IDOIT'S