In Gansu province's Gannan Tibetan autonomous prefecture, "No Littering" is not just printed on signs along the streets but is also written into every village's covenant - a list of rules for which residents voted - so it sticks in people's minds.

The local government initiated a campaign called "No Trash in Sight" two years ago. Now the rule covers the whole jurisdiction.

Around 403 villages in Gannan have earned the title Model Village of Ecological Civilization, an honor for accomplishing the objectives of the campaign. The number of such villages will grow to 1,500 by 2020 under a plan by the local government.

It's easier said than done. People used to think that littering was a minor misbehavior, even though trash could be seen all around cities, villages and along highways.

"At first, I doubted whether this was just a show," Yang Lin, a resident of Hezuo, said of the anti-littering effort. "After all, littering is such a small thing."

But she soon noticed civil servants cleaning streets regularly, and more volunteers joining the campaign. It gradually became routine for every neighborhood in the city.

Plastic bags are no longer offered in the supermarket. People who toss their cigarette butts on the ground get a fine.

"My little daughter will now put the snack wrapper in her pocket and throw it in a trash bin," she said.

Outside the city, the task is harder.

"The hygiene in our village was poor," said Wu Shiying, 62, who lives in Lazan, a model village a 10-minute drive east of Hezuo.

"Garbage, feces and piles of dirt were everywhere," he said.

Over the past two years, the local government has invested more than 1 million yuan ($147,000) in village renovations, replacing dirt roads with concrete ones and building new public toilets.

In the center of the village, a billboard was erected to display the covenant for protecting the environment. It specifies what residents will do to ensure the cleanness and tidiness of public areas.

Residents divided themselves into three groups, managing village hygiene in designated areas, depending on where they live.

"There shouldn't be any difference inside the home or out on the street," the covenant reads.

Wu is head of the third group, and organizes cleanups on Tuesdays and Fridays.

"I didn't care too much about the environment before, but my wife joined the campaign," said Tibetan resident Rigzin Dorjee, 34. "Now I realize that the cleaner the environment, the happier my heart."

A government fund of more than 5 billion yuan has been created for communities across the prefecture to boost tourism.

"These model villages will be like pearls on the grassland, attracting people to visit Gannan," said Yu Chenghui, Party chief of the prefecture.

The prefecture received around 10 million visits in 2016, up from 5 million in 2014.

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