Monthly Archives: August 2009

Aral Sea (former) and Golden Age Lake (future)

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Map of the Month: Aral Sea, Golden Age Lake, and Irgiz-Turgay Basin

Map boundaries: 40 to 50 degrees North; 55 to 66 degrees East

Countries: Kazakhstan (Aktobe, Atyrau, Karagandy, Kostanay, Kyzylorda, and Mangystau), Russia (Baykonur), Turkmenistan (Ahal, Balkan, Dashoguz, and Lebap), and Uzbekistan (Bukhara, Karakalpakstan Republic, Samarqand, and Xorezm)

Overview

The central Asian desert landscapes covered by this map area are drained by streams which flow into closed basins. The fate of two bodies of water and two rivers depend on decisions being made by three countries—Turkmenistan, Uzbekistan, and Kazakhstan. The Aral River is shrinking due to diversion of its two sources of water—the Syr and Amu rivers. The area of the formerly freshwater to brackish “sea” shown on most maps is now inaccurate. Most of the water from the Amu River in Turkmenistan is diverted for irrigation. The drainage is collected in a series of canals and ultimately flows to the site of the former Kara Salt Lake, or to Sarykamish Lake, also in Turkmenistan. The Kara Salt Lake has been renamed Golden Age Lake in anticipation of it successfully collecting the drainage water. The Amu River no longer flows into the Aral Sea in Karakalpakstan. The irrigation around Dashoguz has saturated the ground and brought salt to the surface throughout the region. Numerous saline lakes have formed from the saturated ground. It is hoped that the drainage scheme will cause the water table to drop, allowing for reclamation of saline soils. Continue reading →

Coetivy Atoll

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Map of the Month: Coetivy Atoll and Poydenot Shoal

Map boundaries: 0 to 10 degrees South; 56 to 64 degrees East

Countries: Mauritius and Seychelles

Overview

The northern part of the Mascarene Plateau, the largest submerged bank in the world, is covered with seagrass and interspersed with coral reefs. The plateau extends from the Granitic Seychelles southeast to Saya de Malha Bank, a series of shoals which would be a coral atoll if any of the area was above the ocean surface. Depths are as shallow as 8 m at Poydenot Shoal. To the west is a coral island, Coetivy Atoll. Coetivy is not connected to the Seychelles or Saya de Malha banks. Although the island is only 9.3 square km in area, it is surrounded by a platform reef providing shallow water of 14.2 square km. Covering much of the island are about 200 shrimp or prawn ponds operated by a Seychelles government corporation. Continue reading →