龙门山,北东起于广元,南西达泸定,全长约500千米,宽30～70千米。西、北毗邻川西北山地及高原区,南接成都为中心的川西平原,东与四川盆地北部连为一体。主要包括岷江上游的部分地区和涪江上游的大部分地区,行政区划上主要包括四 Longmen Mountain, North East from Guangyuan, Southwest Luding, a total length of about 500 km and a width of 30 to 70 km. The west and north are adjacent to mountainous and plateau areas in the northwestern part of Sichuan Basin, the western Sichuan plain centered in Chengdu in the south, and the north part of the Sichuan Basin in the east. Including the upper reaches of Minjiang River and most of the upper reaches of Fujiang River, the administrative divisions mainly include four