Hydrological survey of Mianyang
Affected by the landform, Mianyang has abundant precipitation, large runoff, vertical and horizontal rivers and developed water system. There are more than 3000 rivers and gullies in the city. All rivers and gullies flow into Fujiang, Bailongjiang and Xihe, tributaries of Jialing River, belonging to Jialing River water system. Fujiang River is the largest tributary on the right bank of Jialing River, and also the most important river in the city. Its drainage area accounts for 97.2% of the total area of the city, which has a significant impact on the formation of natural geographical environment and economic development of the city. There are many tributaries of Fujiang River. The main primary tributaries in the city include Pingtong River, Tongkou River (Jianjiang River), Anchang River and Kaijiang River on the right bank of Fujiang River; Huoxi River, Furong River and Zijiang River are on the left bank of Fujiang River, forming an asymmetric pinnate water system. There are many floods in the city. The frequency of flood disasters is the highest in Anchang River and the upper reaches of Fujiang River, especially in Beichuan, Anxian and Jiangyou on the right bank of Fujiang River and along the front line of Longmen Mountain in the West.