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一、三峡以上地区的自然特征本地区包括青、滇、川、黔、陕、甘、鄂诸省,位于东经90°～112°,北纬23°～34°。土地面积为99万平方公里,占全流域总土地面积的55％,河流长度为3950公里,占长江总长度的68％,于流宜宾以上的长度占全江之半,面积占全江的28％,宜宾至三峡间加入的主要支流有岷江、嘉陵江和乌江,为长江主要洪峰汇集的河段。三峡以上为我国亚热带气候区,分属青藏高原和东部季风区,在地貌上可以划分为青藏高原、云贵高原、横断山脉、四川盆花,秦巴山地等。四川
I. Natural Features of the Three Gorges Areas The region includes Qing, Dian, Sichuan, Guizhou, Shaanxi, Gansu and Hubei provinces. It is located at 90 ° -112 ° E and 23 ° -34 ° N. The land area of 990,000 square kilometers, accounting for 55% of the total land area of the basin, the river length of 3950 km, accounting for 68% of the total length of the Yangtze River, the length of the stream above Yibin accounted for half of the whole area of ?? 28 %, Yibin to the Three Gorges to join the main tributaries of the Minjiang River, Jialing River and Wujiang River, the Yangtze River main flood peak pool. Above the Three Gorges is a subtropical climatic zone in China, belonging to the Qinghai-Xizang Plateau and the eastern monsoon region. It can be divided into the Qinghai-Tibet Plateau, the Yunnan-Guizhou Plateau, the Hengduan Mountains, the Sichuan Basin and the Qinba Mountains in terms of geomorphology. Sichuan