But the belching smokestacks and car exhaust fumes 4,000 meters below, in the country's interior, are not the only thing to blame for these environmental changes. The Tibetan herdsmen also play a role in the destruction of their region. Owing to strong demand for costly cashmere wool, in recent years, the nomads have been driving bigger and bigger herds across the grasslands. The cashmere goats are particularly aggressive grazers, tearing out stalks of grass with their roots, which causes the ground to become more sandy.
Now fences block access to the nomads' traditional grazing grounds. The government is resettling the herdsmen in other areas, which is creating bad blood with the Tibetans.
The Gesawang Monastery, at the entrance to Madoi, consists of a few stone houses and several nomad tents. It is the religious center of the Yellow River headwaters region. An old monk leads visitors into the main building and tells his story. The Chinese imprisoned him from 1961 to 1980, he says.
Four photos of the Dalai Lama are displayed in the prayer room, one behind an empty bottle of Tuo liquor with artificial red flowers in it. The old man has even set up a symbolic chair for the Dalai Lama, which he has also decorated with a photo.
Displaying photos of the Dalai Lama is strictly forbidden in the Tibet Autonomous Region. But, in neighboring Qinghai, the government rules with a somewhat looser grip, and pictures of the Tibetan monk -- berated by the Chinese government as a "divider" and "traitor" -- can still be displayed. The Dalai Lama, in exile in India since 1959, is also a son of the Yellow River. He was born almost 77 years ago, in the village of Taktser, in Qinghai. Shedding Light on Old Secrets
Lanzhou, the capital of Gansu Province, is about 200 kilometers away. Since the 1950s, the city has grown to become an important center for the oil and chemical industries, and it now has a population of 3.5 million. For a long time, environmental protection was not even a concept here. The city's factories and all of its households simply dumped their sewage and wastewater into the Yellow River. Sewage-treatment plants are only now being built for residential areas.
A cable car takes visitors across the river to the White Pagoda. For his conversation with SPIEGEL, the writer Yang Xianhui, 66, has chosen a nearby teahouse, and not just because of the nice view of the city and the oldest railway bridge across the Yellow River, which German engineers built in the early part of the last century. Yang also feels that he won't be bothered at the teahouse. He has made it his mission to shed light on China's dark past.
Yang wants to document the atrocities of a part of Chinese history that the Communist Party would prefer to keep under wraps even today: Mao's "Great Leap Forward" at the end of the 1950s. At the time, China's leader tried to radically industrialize the country, aiming to catch up economically with the likes of Great Britain "within 15 years." The Communist Party ordered farmers to build small blast furnaces in their fields and make steel. At the same time, it required them to produce more and more grain for the cities. The Great Leap Forward ended in a catastrophe, with up to 45 million Chinese dying of starvation.