Where are the maps? You can upload them using "attach file" option. Make sure that you have the images with your writing because then only we can provide you with more relevant feed backs.
The two maps below show differences of an island, before and after the construction of some tourist facilities.
... differences in what terms? You need to introduce them.
Before the construction, there was
nooneno one living onin the island.
...."nobody" is a better word.
Sea covers around the Island
.... Island means a mass of land covered by the sea and therefore this sentence is not meaningful. Is it something else you try to mean?
After the construction, the island is highly populated.After construction of new facilities, the island has become highly populated.