Problems caused by the Three Gorges Dam construction in the Yangtze River basin: a review

Dam is an important way of water-resources utilization in large rivers. To date, more than 50 000 dams with various sizes have been constructed in the Yangtze River basin, with many other dams proposed to be constructed by 2020. Dam construction has played significant roles in flood control, irrigation, navigation, and energy supply; however, the enormous negative effects, such as landslides, ecological problems, and water quality decline, could surpass positive gains. Although a long and complicated evaluation process had been carried out and the countermeasures for numerous foreseen negative impacts of the Three Gorges Dam (TGD) had been implemented, many uncertainties and debating opinions on the benefits and costs of this project still exist. In this review, we synthesize the negative impacts that have occurred as a result of the TGD, including reservoir-triggered seismicity, landslides, water quality control, ecological problems, siltation, and sediment discharge decline to assure an environmentally friendly operation of the TGD and regional sustainable development in the Yangtze River basin, especially in the Three Gorges Reservoir region.