Juanjiang River is an important river in the northwest mountainous area of Chengdu Plain. Originated in the southwest of Taizicheng Peak (48 14m above sea level) in Longmenshan, Pengzhou City, with a total length of 139KM and a drainage area of 2057.3km2, it is one of the three major sources of Tuojiang River.
Juanjiang River was called Juanshui River, Mengshui River, Pengshui River and Wangcun River in ancient times. After liberation, there was only one main tributary downstream, which was also called Duck River in Deyang City. The tributary of Tuojiang River, a tributary of the Yangtze River, originated in Chaping Mountain in the middle of Longmen Mountain in the north of Pengzhou City, Sichuan Province, and its upstream is called Jinhe River. There is a famous scenic spot, Yinchanggou, Baishui River and Bailu River meet here successively. After leaving the pass (called centralized management in ancient times), enter the plain and cross the Weihe weir. The following reaches are divided into nine tributaries in history. Xiaoshi River is the main flood discharge road, Yazi River is the catchment river along the mountain stream, and the rest has been changed to irrigation canal system. Duck River and Xiaoshi River meet again in Ma Jing Town, shifang city, and flow into Guanghan City in the southeast, which is called Duck River. It flows around the north of Guanghan City, then flows to Sanjiang in the southeast, and then joins Shiting River and Mianyuan River successively. In Jintang County, it is called Beihe River, and in Zhao Zhen, it joins Zhonghe River and Pi River and is called Tuo River. The mountainous area above the mouth of Yujiang River is 65 kilometers long, with an average gradient of 15.3‰ and a drainage area of 626 square kilometers. The plain section from Guankou to the confluence of Kuangjiang River (Duck River) and Shiting River is 57 kilometers long, with an average gradient of 5.24‰ and a flow area of 1.068 square kilometers. The total length of Minjiang River is 122km, and the total drainage area is 1694km2.