Let me give you a simple example.
Originally, everyone was in a big pond (the elemental concentration in the whole environment was the same), but the Kingdom of Ser started its own initiative, turning its kingdom into a circular reservoir and siphoning the surrounding water for its own priority use.
As the water level of the big pond lowered, the reservoir of the Kingdom of Ser rose.
When it was windy or rainy, and the small reservoir of the Kingdom of Ser overflowed, it did not affect itself much, but its neighboring areas would suffer.
This is just a simple metaphor; the situation involving elements is far more complex than this.
For example, to permanently change the environment, one must have a source of strength.
Using regional magic arrays to extract surrounding elements is a more conventional method.
Another clever method is to directly connect with the Elemental Plane and channel its purest elemental power for one's own use to achieve the desired goal.
