The water system of the upper reaches of the Jialing River experienced tremendous changes over the historical period.

The main source comes from the background load, namely natural background load and upstream contribution load from the upper reaches of the Yangtze River, the Jialing River and the Wujiang River.

Located on the edge of the Yungui Plateau, Chongqing is intersected by the Jialing River and the upper reaches of the Yangtze (Changjiang River).