Where on Earth...? MISR Mystery Image Quiz #13: Amu Darya River

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This false-color image of the Amu Darya river was acquired by the Multi-angle Imaging SpectroRadiometer (MISR) in late June, 2002, and represents an area of about 292 kilometers x 370 kilometers. Data from the near-infrared, red and blue spectral bands of MISR's downward-viewing (nadir) camera are displayed as red, green and blue, respectively, causing highly vegetated areas to appear red. Answers to the questions are provided.

1. Three of the following four statements about the two countries contained with image area are true. Which one is false?

   1. They are among the world's top cotton producers.
   2. One celebrates Independence Day in March; the other in April.
   3. They are both landlocked.
   4. Soil in both countries has been subjected to increasing salinization.

   • Answer: B is false
     The Amu Darya river forms a wide delta in the western deserts of Uzbekistan and northeastern Turkmenistan, and the river waters are utilized intensively to irrigate cotton and other crops. During the Soviet era, large irrigation systems were developed and the region became specialized in cotton growing. Independence from the Soviet Union occurred in 1991 and is celebrated by Uzbekistan on September 1st and by Turkmenistan on October 27th. Both of these landlocked countries are losing arable land to soil salinization as a result of rising groundwater levels that accompany crop irrigation.

2. Three of the following four statements about the large water bodies in the upper left-hand corner of the image are false. Which one is true?

   1. Increasing agricultural demands caused a 75% drop in water volume during the last few decades.
   2. Water volume increased by about 15% in the last decade due to a change in the availability of glacial meltwater.
   3. Increased commercial fishing in these waters over the past few decades has led to economic growth in the region.
   4. These freshwater bodies provided the setting for an international athletic competition held in the mid 1990's.

   • Answer: A is true
     As a consequence of the diversion of vast quantities of freshwater from the Amu Darya and Syr Darya rivers, water volume in the Aral Sea has dropped by more than 80% since 1960. Increases in water input near the river's source (from precipitation or glacial meltwater) do not compensate for the water lost from this shrinking inland sea. Commercial fishing in the region has ceased.

3. Three of the following four statements about the major river system that diagonally traverses the image area are true. Which one is false?

   1. Parts of the river demarcate international political boundaries.
   2. The total number of fish species supported by the river system has decreased since the middle of the 20th century.
   3. The direction of water flow is from the upper left portion of the image toward the lower right.
   4. The river changed its course during the 17th century, prompting a city within the image area to relocate and re-build closer to the new riverbed.

   • Answer: C is false
     A portion of the border between western Uzbekistan and northeastern Turkmenistan follows the course of the Amu Darya river. Within the river system, about 50 fish species could be found during the 1960's; that number has dropped to approximately 20. Within the area of this image, the width of the main river is widest in the lower right-hand corner (closer to its source in the mountains of Afghanistan) and is greatly reduced by the time it reaches the edges of the dwindling Aral Sea. However, both the Amu Darya and the Aral Sea have experienced dramatic changes in response to past climate and probably also in response to historical irrigation practices. The new and old site of the city of Urgench is one indication of the river's dynamic nature.

Image credit: NASA/GSFC/LaRC/JPL, MISR Team.