Final answer:
Building the Three Gorges Dam has led to the displacement of over a million people and the loss of historic sites and farmland. The dam heightens the risk of induced earthquakes and has negative impacts on local wildlife, endangered species, and water quality.
Step-by-step explanation:
A negative consequence of building a dam, such as the Three Gorges Dam, to prevent flooding includes environmental and social impacts.
The dam, situated on a fault zone, raises concerns about the potential for induced earthquakes due to the massive weight of the water in the reservoir, which could lead to catastrophic outcomes if the structure were to fail. Additionally, the construction of large dams often results in significant displacement of local populations, as seen with the Three Gorges Dam where 1.24 million people were forced to relocate, along with the inundation of historic sites, villages, and agricultural lands.
The blocking of fish migration and negative effects on wildlife habitats due to the dam are also major environmental concerns. The dam's presence has exacerbated water pollution, increased landslide risks on its banks, and affected critically endangered species such as the Siberian Cranes and the Yangtze River Dolphin.