Friday, August 26, 2016

Mapping Land and Sea Reclamation

Over the last 30 years the Earth has gained 173,000 km2 of land. Most of it from land reclamation projects. However this isn't just a one way process. Over the same time period the Earth gained 115,000 km2 of water. Much of this presumably due to coastal erosion.

The Deltares Aqua Monitor is a fascinating new global map which allows you to visualize land and water surface changes since the year 2000. The map was created by analyzing changes in Landsat satellite imagery. Custom algorithms were created to scan the satellite imagery to detect changes in surface water and discover where water has become land and land has become water.

On the interactive map green overlays show where surface water has been turned into land and blue overlays show where land has been changed into surface water. If you turn on the advanced options on the map you can toggle the changes on and off. You can also view the changes yourself directly on the map by switching between the 2000 and 2015 satellite imagery.

Some of the most dramatic surface water changes can be seen in:

  • the extending lakes in the Tibetan plateau
  • coastal land reclamation along the Chinese coast 
  • the drying up of the Aral Sea
  • the meandering rivers in the biggest deltas

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