Photos and discussions about China’s recent use of heavy-duty drones to “airlift” villagers affected by flooding in Guangxi have gone viral but almost two decades ago, the disaster-prone country once relied on risky, low-tech means to fight natural calamities. China’s rapid tech advancement, represented by the development and deployment of drones, has helped it better handle emergencies, such as how first responders have been rescuing residents from widespread rainstorms and floods since...