China's new $300 billion city

Lin Xiaoman's finger drew a blue track in the holographic projection, and the three-dimensional model of the underground pipeline corridor floating in Xiong'an New Area suddenly showed red ripples. "The water supply and drainage system in District 7 has a flow deviation of 0.3%." She took off her AR glasses. The office at three in the morning was filled with cold light, and the smart street lights outside the window were blurred in the autumn fog.

This data anomaly has troubled the Digital Planning Bureau for two weeks. As a smart city researcher, she knows that in a "city of the future" like Xiongan, a 0.3% error means that an ecological wetland with an area of ​​three football fields may be quietly changing.

The vibration of her cell phone interrupted her thoughts. It was a voice message from her mother: "Man, your Uncle Zhang said that the old locust tree at the east end of the village has sprouted new buds. The White Dew has passed..." Xiaoman looked at the jumping data stream on the screen and suddenly remembered the time when she was a child, she followed her father to catch snails in the reed marshes of Baiyangdian. Her father always said that a thousand-year plan must be nurtured from the earth's veins.

The next morning, Xiaoman rode a shared electric bike to Dazhang Village. The village had become an ecological park after demolition and reconstruction, except for the 600-year-old locust tree, which was protected by a full glass ecological cabin. She squatted down, and the metal pipes of the intelligent irrigation system were oozing crystal water droplets at the roots of the tree, while the moss on the bark was an unnatural indigo blue.

"The little girl also found something wrong?" Xiaoman was so startled by the hoarse male voice that she almost knocked over the detector. She turned around and saw an old man in navy blue overalls, with a badge that read "Qi Weiguo from Baiyangdian Water Conservancy Research Institute".

Professor Qi's calloused hands stroked the temperature control panel of the glass cabin: "The smart pipe network you installed can irrigate 5.2 liters per hour, but ancient trees have their own way of drinking." He took out a yellowed notebook with a specimen of a locust tree leaf in the hydrological record of 1976. "Do you see the golden lines in the veins of the leaf? This is the calcium precipitation unique to Baiyangdian."

The midday sun penetrated the eco-cabin, casting tiny spots of light under their feet. Xiaoman's smart bracelet suddenly vibrated, and the monitoring data showed that the root temperature of the locust tree was 2.7℃ lower than the surrounding soil. She remembered what her father said, that the roots of old trees can sense the direction of water veins eight meters underground.

"How about we do an experiment?" Professor Qi took out a copper compass from his canvas bag, "This is what my grandfather's generation of canal workers used. Although it's not as good as your quantum sensor..." Before he finished speaking, the compass needle suddenly spun wildly and finally pointed to the southeast - the direction of the main control well of the smart pipeline network.

For the next three days, Xiaoman took the quantum sensor device and took root under the ancient locust tree. When she superimposed the hydrological map of 1902 with the real-time monitoring data, the holographic projection suddenly showed strange resonant ripples. It turned out that the roots of the ancient locust tree formed a natural siphon with the intelligent pipe network 30 meters away, just like the reeds in Baiyangdian Lake regulate the humidity of the wetland through pores.

"The breathing rate of the ecosystem is 0.83 times per minute." Xiaoman called up the data model at the project report meeting, "Our smart irrigation system is set to the growth rhythm of the European spruce." The meeting room suddenly became quiet, and she saw the pen in the director's hand leaving ink spots on the "Smart City Assessment Report."

On the day of the autumnal equinox, Xiaoman stood on the top floor of the newly built Citizen Service Center. Below her was the rain garden unique to the sponge city, and in the distance the blue waters of Baiyang Lake reflected the silver light of the photovoltaic panels. She turned on the newly developed bionic sensor system, and the root data of 500 ancient trees stretched into a green neural network in the cloud.

My phone vibrated again. This time it was a photo sent by Professor Qi: the newly grown branches of the ancient locust tree passed through the skylight of the eco-cabin, a red-footed falcon was perched on the tender leaves, and the smart pipe network interface at the tree root was flashing a faint blue fluorescence. The caption of the photo: "The old tree is teaching the new system to sing a fishing song."