How does the process unfold?
I find this question unnecessary.
There are 3 main stages shown on the diagram: evaporation of ocean water, precipitation and dripping water to the sea.
This sentence could be used in the overview paragraph as it shows readers the most remarkable features of the diagram.
The evaporation which contributes 80% of water vapor in the air coming from the oceans is awarded the first stage in the diagram.
At the evaporation stage, 80% of water vapor in the air come from the oceans.
At the second stage, there presently is precipitation, which is the amount of water falling on the ground coming second in this process.
This is followed by the precipitation stage, in which water falls from the ground in the form of rain or snow.
Again, this water forms snow at the top of the mountain.
I think the snow is the result of precipitation rather than the water in mountainous lakes.
produce water from ocean to land
The word "produce" is not appropriate here to me. In my opinion, water just changes its states throughout the cycle.