The main factors that affect the salinity of sea water are:
1. The relationship between precipitation and evaporation. The precipitation is greater than the evaporation, the salinity is low;
2. Sea areas with warm currents have higher salinity, and sea areas with cold currents have lower salinity;
3. The salinity of the sea area where a large amount of fresh water is injected is low;
4 The more closed the shape of the sea area, the more the salinity will tend to be higher or lower.
