嘉陵江是长江上游主要支流之一,发源于陕西凤县秦岭南麓,流经陕西、甘肃、四川等3省,11个地市州,76个县。流域面积15.8万平方公里,占长江流域面积的9％,总人口约4000余万(四川占90％)。主要支流有西汉水、白龙江、渠河、涪江等,先后在略阳、广元、合川汇入干流,在重庆朝天门注入长江。干流全长1120公里,广元以上为上游,广元至合川为中游,合川至重庆为下游。此外较大支流还有西河、东河。流域上游有岷山、秦岭、米仓山、大巴山等山脉,西缘与青藏高原相连,河谷深邃狭窄,河床比降大,两岸耕地稀少。中下游为四川盆地,四周由山区、深丘过渡为红色丘陵,绵延数百里,地势平缓,农田集中,为四川主要 Jialing River is one of the main tributaries of the upper reaches of the Yangtze River. It originated from the south foot of Qinling Mountain in Fengxian County of Shaanxi Province and flows through 3 provinces, 11 prefectures and cities and 76 counties in Shaanxi, Gansu and Sichuan. The basin covers an area of ​​158,000 square kilometers, accounting for 9% of the Yangtze River Basin. The total population is about 40 million (Sichuan accounts for 90% of the total population). The main tributaries of the Western Han River, Bailongjiang, Drainage River, Fujiang, successively in Lueyang, Guangyuan, Hechuan into the main stream into the Yangtze River in Chongqing Chaotianmen. The total length of 1120 kilometers of the main stream, Guangyuan above is upstream, Guangyuan to Hechuan middle reaches, Hechuan to Chongqing for the downstream. In addition there are larger tributaries of the West River, East River. There are Minshan, Qinling, Micangshan and Dabashan mountains in the upper reaches of the river basin. The western margin is connected to the Qinghai-Tibet Plateau. The river valley is deep and narrow. The riverbed ratio is lower than that of the other two sides. The middle and lower reaches of the Sichuan Basin, surrounded by mountains, deep mound transition to red hills, stretches hundreds of years, flat terrain, concentrated farmland, mainly in Sichuan