what is run off

Runoff refers to the unconfined flow of water over the ground surface, occurring when excess rainwater, stormwater, meltwater, or other sources cannot sufficiently rapidly infiltrate the soil. This can lead to flooding and erosion, and it occurs when there is more water than the land can absorb. Runoff can have significant economic effects and can impact agricultural crops and vegetation. Additionally, runoff can be reused through the growth of certain plants, such as elephant grass in Nigeria, which is considered an economical way to reduce surface runoff and erosion. In a different context, a runoff can also refer to a final race, contest, or election to decide an earlier one that has not resulted in a decision in favor of any one. For example, a runoff election is held when the initial vote did not result in a winner due to a tie or being too close to call.