Earth Observations taken by the Expedition 25 crew

ISS025-E-005504 (30 Sept. 2010) --- Syr Dar’ya River floodplain in Kazakhstan, central Asia is featured in this image photographed by an Expedition 25 crew member on the International Space Station. Central Asia’s most important cotton-growing region is concentrated in the floodplain of the Syr Dar’ya, and is irrigated by water from the river. The floodplain is shown here as a tangle of twisting meanders and loops (center). The darkest areas are brushy vegetation along the present course (filled with blue-green water); wisps of vegetation are also visible along flanking swampy depressions, or sloughs. An older floodplain appears as an area of more diffuse dark vegetation (upper left), where a pattern of relict meander bends is overlain by a rectangular pattern of cotton fields. The straight channel of a new diversion canal—one of sixteen from this point downstream—can be seen along the east bank of the river. The older floodplain area is fed from the Chardara Reservoir immediately upstream (not shown). Half the river flow is controlled from reservoirs, and half from direct water take-off from canals. By contrast with the intensive agricultural use of water shown here, upstream water control in the mountain valleys is oriented more toward power generation. The river flows for a total distance of 2,200 kilometers from the Tien Shan Mountains westward and northwestward to the Aral Sea—the dying waterbody at the low point of the basin far to the northwest. Withdrawals of water from the river for agriculture have continued for many decades. Although the Syr Dar’ya is the second largest river flowing into the sea, its discharge is not very large. As such, it has been easily depleted, with none of its water today reaching the Aral Sea. Control of the river is vested in the Syr Dar’ya Basin Water Organization run by nations with territory in the Syr Dar’ya basin. Some of the organization’s main efforts are accurate gauging of water use along the river course, and repair of canals to reduce widespread water loss by leakage.