Why is there a flood season?

The occurrence of flood season is due to seasonal precipitation and melting ice and snow in river basins, which leads to the regular rise of water level. The flood season is the largest and most concentrated period of precipitation in a year. Although it brings abundant water resources, it is easy to cause floods.

The specific reasons are as follows:

1. Rainwater supply: the eastern monsoon region is the most typical, mainly in summer and autumn, and the flood season appears in the rainy season.

2. Seasonal snow melt water replenishment: (Northeast) Spring, spring flood occurs.

3. Permanent snow melting: (Northwest China and Qinghai-Tibet Plateau) mainly occurs in summer, and the flood season occurs in summer, with little runoff.

4. Lake water supply: (Changbai Mountain in China and Tianchi Lake in the middle and lower reaches of the Yangtze River) is available all year round, which can adjust the river flow.

5. Groundwater recharge: (Upper reaches of Xiaoqing River in Jinan, China; Southwest karst landform area has the most stable supply all the year round.