The Bohai Sea is China's continental sea, while the Yellow, East China and South China seas are marginal seas of the Pacific Ocean. A total of 5,400 islands dot China's vast territorial waters. The largest of these, with an area of about 36,000 square km, is Taiwan, followed by Hainan Island with an area of 34,000 square km. China's topography is varied and complicated, with towering mountains, basins of different sizes, undulating plateaus and hills, and flat and fertile plains. A bird's-eye view of China would indicate that China's terrain descends in four steps from west to east.
China abounds in rivers.
More than 1,500 rivers each drain 1,000 square km or larger areas. More than 27,000 billion cu m of water flow along these rivers, 5.8 percent of the world's total. China has a marked continental monsoonal climate characterized by great variety. Northerly winds prevail in winter, while southerly winds reign in summer. The four seasons are quite distinct.