South Aral Sea Syr Darya, would be diverted in order to irrigate cotton and food crops in Kazakhstan and Uzbekistan. In 1986, due to an accelerated loss of water, the Aral Sea was split into northern and southern parts; the northern part is the current North Aral Sea. In 2007, the western basin had a salinity of 70 g/l and the eastern basin 100 g/l. Once the water level falls below the connecting channel (elevation 29 m), the salinities can be expected to diverge further. Under current conditions, the eastern basin may receive water from the Amu Darya in wet years, fluctuating in
Kazakhstan–Uzbekistan border sparsely populated and traverse largely desert areas, in stark contrast to the western third which is densely populated, containing some of the largest towns in Uzbekistan and southern Kazakhstan. The eastern-most section is mountainous and contains a series of national parks (Sayram-Ugam National Park and Aksu-Zhabagly Nature Reserve in Kazakhstan and Ugam-Chatkal National Park in Uzbekistan. Uzbekistan’s Jizzakh to Sirdaryo railway crosses through Kazakhstan briefly, a legacy of the Soviet era where infrastructure was built without regard to what were then internal boundaries. Russia had conquered Central Asia in the 19th century by annexing the formerly independent Khanates of Kokand