The wetlands along northern China's biggest river system are drying up because of the thirst of an expanding population and a fast-growing economy, Xinhua news agency reported. Xinhua said 12 main sections of wetlands along the reaches of the Haihe River, which used to cover 3,800 sq km (1,465 sq miles), have shrunk by more than 80 percent over the past five decades to just 538 sq km (207 sq miles). The Haihe is formed by five large rivers that spread out like a fan over vast areas of northern China and converge near Tianjin, a bustling port city southeast of Beijing.