View Full Version : MODIS: Floods in Afghanistan

tlr online
11-03-05, 02:02
The most severe and arduous winter in a decade set Afghanistan up for severe floods, which arrived over the two weeks between February 21 and March 7, 2005. The saltpan plains—once the Sistan Wetlands—of western Afghanistan (right) and eastern Iran (left) are filling with water. In the this brief period of time, the border region went from arid plain to water-soaked wetlands. According to Agence France-Presse (AFP), the floods have killed three people and destroyed about 300 houses in Afghanistan. Officials fear that flooding could intensify as temperatures rise and winter snows begins to melt.

The Sistan Wetlands have been steadily drying out in the grip of an extended drought that started in 1998. (See “From Wetland to Wasteland”) The former extent of the wetlands is visible in the false-color rollover image, taken by the Aqua MODIS instrument on February 21. Evaporating water left white salt flats, which are a lighter shade of tan in this image. The top false-color image, taken by the Terra MODIS instrument on March 7, 2005, shows that flood waters have filled the depressions left by the former wetlands.

In this color combination, the tan desert soil has a slightly pink tint, clouds are light blue, plant-covered regions are bright green, and clear water is black. Because dirt scatters light, it colors the water blue. Clearer, deeper water is a dark shade of blue, while shallow, mud-laden water is lighter blue. Beyond causing wide-spread floods, the rain has spurred plant growth, particularly in Iran, where the wetlands are considerably greener on March 7.


Copyright 2005 NASA