Flash floods in Beijing have killed over 70 people and forced the evacuation of more than 50,000 after destroying over 8,000 homes and causing $1.6 billion in damages. In total, some 1.5 million people have been affected by the floods after Beijing recorded the heaviest rainfall the city has seen in more than 60 years.
The heavy rains began on July 21. Within hours, users of the Guokr.com social network launched a campaign to create a live crisis map of the flood’s impact using Google Maps. According to TechPresident, “the result was not only more accurate than the government output—it was available almost a day earlier. According to People’s Daily Online, these crowd-sourced maps were widely circulated on Weibo [China's version of Twitter] the Monday and Tuesday after the flooding.” The crowdsourced, citizen-generated flood map of Beijing is available here and looks like this: