The terrain of the republic encompasses two unequal sections: the larger northwest area, which is part of the Kyzyl Kum desert; and the smaller southeast area, which has fertile loess soil and touches on the Tian Shan mountain system. The Aral Sea lies on the northwest frontier. Central Asia's two major rivers—the Amu Darya and Syr Darya—pass through Uzbek territory. The Khiva oasis is irrigated by the Amu Darya, the fertile Fergana Valley by the Syr Darya and its tributaries, the Tashkent oasis by the Chirchik and Angren rivers, and the Samarkand and Bukhara oases by the Zeravshan. Uzbekistan has a dry continental climate. In the Fergana Valley, several small sections of Uzbekistan form enclaves in Kyrgyzstan, and there are a Kyrgyzstani and a Tajikistani enclave in Uzbekstan. The jumbled geography has led at times to border incidents.
The Uzbeks, a Turkic-speaking group who have a Persian culture and are mostly Sunni Muslims, make up 80% of the population. Russians (who live mostly in the cities) constitute more than 5%, and there are Tajik, Kazakh, Karakalpak, and Tatar minorities. About 10% of the population belong to the Orthodox Eastern church. Uzbek is spoken by about 75% of the people; other languages include Russian and Tajik.