Section 02 of 04
Subsidence
Ground that goes down when the water goes out. Four pages, and the measurements behind them.
- 01Jakarta, several metres downPumping groundwater from beneath a coastal city compacts the sediment and the surface drops, which is a different problem from sea level rising.
- 02Mexico City's drains run uphill nowUneven subsidence across a former lake bed has changed the gradients the drainage was designed around.
- 03Why the ground does not come back upCompaction of fine sediments is largely permanent, so the lost storage is lost even if the water returns.
- 04Measuring a sinking citySatellite radar interferometry maps millimetres of movement across a whole city, which is how the extent became undeniable.