| china's war on waste and pollution. | the water level of one of the longest rivers in the world, the yangtze in china, fell 20 cm below sea level in february 1993 at shashi in hubei province, the lowest water level in 20 years. in 1993, black-headed gulls left for their annual migration 3 months early because the deteriorating water environment in dianchi lake in kunming, yunnan province, could not support them. china's total surface run-off is among the world's top 5. yet it suffers a water deficit due to its large population size ... | 1993 | 12287012 |