After working for 31 years to protect the environment in northern Tibet's Nagqu prefecture, Zhong Weibin plans to retire in one or two years. The 54-year-old has a handpicked successor, his daughter, to carry on his mission to preserve the plateau.

Zhong Kun, 25, is his only child and became his colleague in 2010 at the prefecture's environmental protection bureau. In September, she was sent to the bureau's law-enforcement team and will make frequent visits at construction sites to check if there are pollution violations.

The father is familiar with the job and its demanding workload and harsh conditions, at an average altitude of 4,500 meters and a volatile climate. Hail and snowstorms are not uncommon in Nagqu, the father says.

With his age and experience, he is entitled to retirement already, as the autonomous region allows officials to retire five or more years early if they have worked in the region for more than 25 years and in areas with an altitude higher than 4,300 meters.

But the bureau in Nagqu is badly short of hands, he says.

A former army scout serving in Northeast China, he has full confidence that his daughter has the inner strength to take whatever difficulties are to come.

It is not the first time he has left her in challenging situations. Zhong Kun was brought up in Sichuan province by her maternal grandmother and has spent little time with her parents.

She enrolled in Changsha University of Science and Technology, majoring in environmental engineering. Father and daughter formed a tacit understanding that she would follow in his footsteps and work in Nagqu after graduation.

She had some doubts. Her good performance at school won the trust of a professor and earned the offer to work as a research fellow. It was hard to resist a more comfortable life in Changsha, capital of Hunan province.

In the end, she chose to stay closer to her father. "I realized family is important to me," she says.

The father has seldom had holidays or weekends these years. He stayed for months in different counties under the jurisdiction of Nagqu prefecture from 1985 to 1995. With his broad smile on a sun-tanned face and his mastery of the Tibetan dialect, he can be easily mistaken as an ethnic Tibetan.

Galsang Degyid, his Tibetan colleague, says the workload makes it impossible to take a full annual leave. In her case, that's 60 days a year, since she began working there in 2004.

Zhong himself has not yet had time to check out his newly furnished home in Chengdu, Sichuan province. But there's no photo had been taken of the three family members together.

As an only child, Zhong Kun was not spoiled and has shown her ability to live independently.

Her father always urges her forward. "If your body adapts well, it is quite interesting to work in Nagqu. People in northern Tibet are honest and straightforward, but illiteracy and poverty are still widespread."

"Plus, Nagqu lacks talents, and her training in environmental engineering is relevant and useful here," he says.