Chongqing- With the continuous hot weather in southwest China's Chongqing, known as one of the "furnace cities," how can the city water its green plants?

In an interchange's three-dimensional greening and watering operation site of 620 square meters, the traditional sprinkler has been replaced by the intelligent drip irrigation system, which can remotely monitor the soil's humidity and temperature and enable sprinkler and drip irrigation through mobile phones.

Chongqing developed various ways to water and cool the plants during the summer. (iChongqing file photo)

By combining technologies such as the Internet of Things, wireless communication, and automatic control, the intelligent irrigation system can quickly implement regular, cyclic, and remote irrigation. A wireless valve controller can be controlled remotely from a cell phone or computer to open, close, and set the opening, irrigation, and end times.

As the terminal collects environmental data, such as soil temperature and humidity, the system will analyze the data and present it to the user in graphs so that the user can make the most sensible watering decisions based on the statistics. 

"We improve seedling preservation through intelligent and refined operations," said Liao Congquan, director of the Greening Division of Chongqing Municipal Bureau of Urban Management. Now Chongqing is taking initiatives to prevent droughts and protect seedlings, arranging the time and volume of watering based on plant attributes to cool plants down.

According to statistics, the central city's management department has dispatched 19,203 person-times and 5,880 watering vehicles since August, watering an area of 113 million square meters. Chongqing has consolidated the upward trend of urban landscaping in recent years.

During the summer, the busy green workers worked till the early morning every day. (iChongqing file photo)

In addition to the intelligent system, the traditional sprinkler has also been upgraded. At the green node of the airport carousel in the Yubei District, the spray from the sprinkler gun is not water jets but a water mist.

"We have improved the water gun to improve the watering effect," added Liao. Although water jet sprinklers may seem to water the plants, high-pressure water jets may hurt the plants. Because the water flows too fast, it "runs" away before it can penetrate the soil. Plants can retain moisture better with a water mist spray operation, instead. 

Aside from the sprinkler operation, a spray system is installed in some green nodes of the city to replenish water and cool the plants in the green areas. Since the hot weather began, the Yubei District Urban Management Bureau has extended the watering operation time of the urban green spaces more than once in the morning and evening.

(Yang Qinmei, as an intern, also contributed to this report.)