Terrain refers to the horizontal and vertical surfaces of the land. It is often spoken of in terms of elevation, slope and the orientation of particular land features. Depending upon certain circumstances, terrain can affect the flow of water, where bodies of water are located and in what quantity. It can even affect weather and climate.
Suitability for human life is determined by terrain. Picture a large swath of desert and a high rocky crag. How difficult would it be for people to sustain life in such terrains? What people wear, eat and how they construct dwellings is determined by terrain.
Your task is to write a story in a challenging terrain. You might have to do some research first to get ideas about how difficult it would be to live there. Your story can be science fiction or contemporary. It can take place in the past or in the future.
The important thing is to choose a terrain that may not be the most hospitable. Don’t rely on exposition to tell the story: have characters interacting with each other as they navigate survival.
Have fun with this one.