Amu-Darya Estuary, Gallery. RDC ScanEx

Gallery

Title
Amu-Darya Estuary

Acquisition date
29.07.2000

Sensor
Landsat-7 ETM+

922 x 864
BMP (3 112 Kb)

Amu-Darya Estuary

Amu-Darya is the largest river in the Middle East. It flows from the northern slope of Gindukush and runs into the Aral Sea. Once a full-flowing river it has shoaled greatly. These days its waters do not reach the Aral being lost in the estuary area. The majority of natural lakes and swamps dried out. Flood plain bushes survived only along banks of artificial reservoirs. This is primarily due to water draw-off for field irrigation and lowering of the Aral Sea level. Swamping occurred and numerous lakes formed in the irrigable part of the estuary and desertification and soil salinization rate increased in its non-irrigable part. Due to catastrophic changes to the environment landscapes with suppressed vegetation are typical for the biggest part of the estuary. The image acquired by the ETM+ imaging system of Landsat-7 satellite displays the northern part of Amu-Darya estuary and the southern part of the Aral Sea. The image was acquired on July 29, 2000 in the red, green and blue spectral zones. Water objects in the estuary area are shown in black. Their occurrence is primarily connected with anthropogenic activity – artificial water retention using dam and channel system. Often lakes are surrounded by reedstand, which is reflected in brown. Tints of green correspond to the healthiest vegetation.

This is indicative of the presence of an oasis in the south-western part of the image. Closeness to sandy color indicates the degree of vegetation dryness. Drying zone is characterized by streaky image pattern, which is due to alternating sand and slit deposits. Yellow color on the image represents sands, while white and tints of blue show salinization areas. Deserted strip in the coastal area that appears on the image is associated with occurrence of sandstorms moving sands and salts to the fertile part of the estuary. In the western part of the image there is Ustyurt plateau. It represents clay desert with some solonchak (alkali soil) spots. On of those – Barsakelmes shor – is reflected in white on the image. Soil layer is disturbed on the plateau roads therefore they show up in light lines.

In the northern part of the image there is Vozrozhdeniya (Rebirth) Island. With further lowering of the sea level it is likely to get larger and divide the Aral into western and eastern parts. The image displays a narrow strait connecting them from the south. Sea depth can also be traced on the image: minimal depth is indicated by light tints of green, while maximum depth is shown in the darkest tint.

Title:	Amu-Darya Estuary
Acquisition date:	29.07.2000
Sensor:	Landsat-7 ETM+

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©2005-2010 R&D Center ScanEx. All Rights Reserved.
mailto: webmaster@scanex.ru