The Aral Sea
The Aral Sea in central Asia has undergone major changes since the 1960s. Once the fourth largest lake in the world, it is now a fragmented series of smaller water bodies. Landsat
satellite imagery has been used to monitor and measure the change to the lake surface and surrounding lands. The Landsat images shown were developed from as many as twelve individual Landsat scenes mosaicked to provide an image of the full sea region.
In the 1960s a massive water diversion project shifted water from the Amu Darya river system, the major source for the Aral Sea, to upstream irrigation. The result was a significant development of agricultural production in the region. At the same time, by 2005 the lake had shrunk to 10% of its previous size. A drought in the mid-2000s caused further decline. Water quality also declined as the more salty remaining water became increasingly polluted with fertilizer and pesticides. Blowing dust from exposed shorelines created major health hazards.
The construction of a dam in the northern unit has led to a rehabilitation of the immediate area around the dam. The southern, or lower portion, continues to shrink, especially the eastern, more shallow water body.
Regional and global environmental organizations have used the Landsat data and other remotely sensed data to study the region and plan for ways to compensate for the dramatic alteration of the once great lake.