asian cities bangkok is maybe a classical example where the center of the city has sunk two or three meters in the twentieth century making it much more prone to flooding tokyo has sunk up to four meters in the twentieth century but the entire city but the bit of the city built on the delta around the port has gone though up to four meters asarco in japan has gone down three meters tianjin gone down two meters shanghai has subsided three meters jakarta in indonesia subsided four meters and is still subsiding very fast today manila probably a meter of calcutta and aca we re not really sure but they re almost certainly going down and then places like new orleans new orleans has subsided up to three meters and is continuing to subside vancouver in canada areas there have subsided
since one thousand nine hundred sixty six pumping from the water tables has been strictly regulated in shanghai yet to ground subsidence continues at a rate of six millimeters per year. some blame is being put on its many buildings some scientists believe the weight of the huge new skyscrapers is in. creasing ground subsidence. no expert is willing to comment on this at present. yet the information has been officially published by the institute for ground subsidence in shanghai. in recent years with the launching of large scale urban construction land subsidence has accelerated. in spite of the possible consequences buildings continue to be built this chinese dream seems unstoppable. but that. elsewhere in the country new urban
change the city built an extensive surveillance network. this is our ground subsidence monitoring network for shanghai. it s made up of thirty seven land subsidence monitoring stations. here and one of the this is where we monitor the evolution of ground subsidence and the different layers at various steps. today the measurements occur it out fully automatic lay the real time monitoring of the different soil layers makes it possible to observe the variations of subsidence more than two hundred meters below the surface today we extract less than ten million tons of water every year as a consequence our level of subsidence remains under six million.