Environmental issues in Kazakhstan at the Semipalatinsk nuclear testing facility (in fact a large zone south of Kourchatov (Курчатов)) and along the Chinese border. The Central Asian Regional Environmental Center is located in Kazakhstan, which fosters regional cooperation on environmental issues. Most of Kazakhstan’s water supply has been polluted by industrial and agricultural runoff and, in some places, radioactivity. The Aral Sea, which is shared with Uzbekistan, has shrunk to three separate bodies of water because of water drawdowns in its tributary rivers. A Soviet-era biological weapons site is a threat because it is located on a former island in the Aral Sea that
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