Turpan city is located to the southeast of Urumqi, the capital city of Xinjiang Uygur Autonomous Region. Turpan is an important city along the ancient Silk Road and the transportation here is very convenient, which enables people from different regions to keep contact easily. It is considered to be the hub between Xinjiang and the eastern part of China. Turpan has long been the centre of a fertile oasis (with water provided by the karez canal system) and an important trade centre. It was historically located along the Silk Road's northern route, Turpan has a harsh, drastic, cold desert climate , with very hot and long summers, and cold but short winters, and brief spring and autumn in between. Annual precipitation is very low, amounting to only 15.7 millimetres (0.62 in). However, the very heat and dryness of the summer, when combined with the area's ancient system of irrigation, allows the countryside around Turpan to produce great quantities of high-quality fruits such as grapes and melons.