What are the types of water supply in Hechuan?

The types of water supply in Hechuan are atmospheric precipitation, seasonal snowmelt water, permanent snow and glacier melt water, lake water and groundwater. According to relevant data, there are five types of river water supply: atmospheric precipitation, seasonal snowmelt water, permanent snow and glacier melt water, lake water and groundwater. Atmospheric precipitation: mainly distributed in summer and autumn, with relatively concentrated precipitation. Seasonal snow melting: mainly occurs in spring, and the weather gets warmer. Permanent snow and glacial meltwater: It occurs in arid and semi-arid mountainous areas and some warmer mountainous areas. Lake water: Lakes in mountainous areas often become the source of rivers. Lakes in the middle and lower reaches of the river can collect a large amount of incoming water from the lake area and increase the river flow. Larger lakes can regulate river flow. Groundwater: It is a reliable and regular source of river water. For rivers that are mainly replenished by groundwater, the flow hydrograph changes gently, and the runoff is distributed evenly within the year, with little interannual change.