Geography of Kazakhstan the water in Kazakhstan is polluted by industrial effluents, pesticide and fertilizer residue, and, in some places, radioactive elements. The most visible damage has been to the Aral Sea, which as recently as the 1970s was larger than any of the Great Lakes of North America save Lake Superior. The sea began to shrink rapidly when sharply increased irrigation and other demands on the only significant tributaries, the Syr Darya and the Amu Darya (the latter reaching the Aral from neighboring Uzbekistan), all but eliminated inflow. During the Soviet Era, Kazakhstan received water from Tajikistan and Kyrgyzstan, and Uzbekistan, Turkmenistan,
Transport in Uzbekistan of inland waterways. Since the mid-1990s, commercial travel on Uzbekistan's portion of the Amu Darya has been reduced because of low water levels. As of 2010, Uzbekistan had 10,253 kilometers of natural gas pipelines, 868 kilometers of oil pipelines, and 33 kilometers of pipelines for refined products. As of 2012, Uzbekistan has 53 airports. 33 of them have paved runways, six of which had runways longer than 3,000 meters. The largest of them, Tashkent International Airport, is linked with European and Middle Eastern cities by direct flights of Aeroflot, Lufthansa, and Turkish Airlines, and with New York and Los Angeles