Final answer:
The Three Gorges Dam has reduced flooding along the Yangtze River but caused the displacement of 1 million people and the submergence of cultural sites. It raises seismic concerns and environmental impacts, while providing economic benefits through hydroelectric power and improved transportation.
Step-by-step explanation:
Since the construction of the Three Gorges Dam, several events and effects have been noted. The dam has indeed reduced downstream flooding along the Yangtze River, which was a primary motivation for its construction. Historic floods in 1954 and 1998 demonstrated the urgent need for flood control measures. The dam's reservoir has unfortunately also resulted in the displacement of over 1 million people, and the submergence of cultural heritage sites and fertile agricultural land, impacting communities and their livelihoods.
Moreover, the dam's presence in a fault zone raises concerns regarding the potential for seismic activity, which could threaten the dam's structural integrity. Environmental impacts also include changes to the natural water habitat and challenges to biodiversity. Yet, on the economic front, the Three Gorges Dam contributes positively by generating a substantial amount of electricity for central China and enhancing the Yangtze River’s capacity for transportation, benefiting trade and connectivity within the region.