TURFAN DEPRESSION

Wade-Giles romanization T'u-lu-p'an P'en-ti, Pinyin Turpan Pendi, deep mountain basin in the Uighur Autonomous Region of Sinkiang, China. The Turfan Depression is a fault trough, descending at its lowest point to 505 feet (154 m) below sea level (the lowest elevation in China), whereas the neighbouring Tarim River and Lop Nor areas are between 2,000 and 3,000 feet (600 and 900 m) above sea level. The basin has an area of 20,000 square miles (50,000 square km). The basin lies between the Po-ko-ta Mountains to the north and the northern section of the K'u-lu-k'o-t'a-ko range to the south. Within this depression another major fault forms the Cheh-lo-t'a-ko Mountains, which divide the basin into two sections. The northern section forms a zone at the foot of the Po-ko-ta range. This area, about 500 feet (150 m) above sea level, drains into the lower southern depression through steep canyonlike gorges. The lower basin, once the site of a permanent lake, slopes toward the south where there is a salt swamp called Lake Ai-ting. The whole basin is irrigable, either (in the north) using surface water or (in the south) by the Persian technique of using tunnels that tap groundwater from higher areas. The area has great climatic extremes: the average monthly temperature is 14 F (-10 C) in January and 90 F (32 C) in July. Daily variations from these averages, however, can be enormous. The highest temperature recorded in China, 118 F (48 C), was at Turfan in the northern part of the basin, while the lowest recorded temperature, -62 F (-52 C), was at Fu-yun, not far from Turfan. Rainfall in the depression is scanty, with only 0.61.2 inches (1630 mm) per year. The extreme temperatures and windblown sands are major problems for the basin's inhabitants. The basin is intensively farmed and is well known for its fruit, particularly Ha-mi (Hami) melons and grapes. Watermelons, apples, peaches, apricots, and nuts are also produced. The area also grows cotton and silk in addition to grain crops, especially wheat. The inhabitants are almost entirely Uighur Muslims. The higher northern part of the depression forms long-established natural routes leading from the trade route known as the Kansu, or Hosi, Corridor to the southeast. The main centres of population in the depression are the cities of Turfan to the north and T'o-k'o-sun (Toksun) at the western end.