THE OASIS IN ITS GEOGRAPHICAL FEATURES
Stein describes the oasis of Khotan in terms of its geography. He says it has from early times been the largest and most important cultivated territory in the south of the Tarim Basin. On the one hand the territory presents the natural features typical of the oases found on the fringe of the great desert of Chinese Turkestan. However, its position, size, and historical past are unique. The geographical position of the Khotan oasis gives it its wealth and importance. It occupies a mighty terrace of fertile loess which has an unbroken length of 40 miles from the foot of the outer hills of the Kun-lun range. It is given ample irrigation from the Yurung-kash and Kara-kash rivers which emerge into the plain immediately above Khotan. Stein has undertaken an expedition from Khotan southward into the mountain range of Karanghu-tagh and toward the headwaters of the Yurung-kash leading to a snowy range of mountains. The two rivers of Khotan bring down a vast volume of water during the months when the sun is powerful enough to melt the snow and ice of the high ranges. Khotan owes its very existence to these two rivers.
A dust-laden atmosphere envelops Khotan for most of the year, with frequent sand-storms. The development of a process of irrigation has been responsible for the accumulation of silt from the rivers. This has contributed to the fertile soil of the area. Cultivation begins at the place where the rivers debouch into Khotan and continues to spread out fan-like over a broadening area to the north. A broad desert of stony detritus, gravel, and coarse sand up to 70 miles wide separates the two rivers, making it difficult to use irrigation techniques in this part of the area. Irrigation has to deal with these difficulties and with water loss from various processes. Large canals take off from the rivers below their débouchement point, and the height at which these canals have b...