“…The country's scale and complex topography have resulted in diverse river and climatic systems, including tropical, subtropical, semi-arid, arid, inland and coastal if the height is between 5 to 15 m, and over 45,000 such large dams exist around the globe. China has almost half of these dams with more than 22,000, followed by the United States (6,600), India (4,300), Japan (2,700), and Spain (1,200) (Silk et al 2005 (Liu and Speed 2009;Speed 2009a). Figure 2a shows the distribution of China's major watersheds.…”