KIZYL-KUM, a desert of Western Asia, stretching S.E. of the Aral Lake between the river Syr-darya on the N.E. and the river Amu-darya on the S.W. It measures some 370 by 220 m., and is in part covered with drift-sand or dunes, many of which are advancing slowly but steadily towards the S.W. In character they resemble those of the neighbouring Kara-kum desert (see Kara-kum). On the whole the Kizyl-kum slopes S.W. towards the Aral Lake, where its altitude is only about 160 ft. as compared with 2000 in the S.E. In the vicinity of that lake the surface is covered with Aralo-Caspian deposits; but in the S.E., as it ascends towards the foothills of the Tian-shan system, it is braided with deep accumulations of fertile loess.