Here is the full list of all 39 Arid achievements.
Survive 50 days in the game (any difficulty).
Complete the game on Survivalist or harder difficulties.
Complete the game on Dead Man Walking.
Read all 36 letters, notes and journals.
You discovered the secret of the waterfall.
Repair all 84 facilities (including story related).
Find the Bath Tub.
Found an old acquaintance.
Survive 10 days in the game (any difficulty).
Fix the bridge to get access to the refuge.
Encounter a sandstorm.
You escaped the atacama desert alive!
Complete the game on Tourist or harder difficulties.
Complete the game on Explorer or harder difficulties.
Obtained the Flare Gun.
Find where the kid has gone.
Craft a herbs poultice.
Run away from the bees! Maybe it's safer at night..
Got access to the Saltpeter Plant.
Reach the Moon Valley.
Opened the way in the Canyon.
Discover what happened to the miners.
Find the unfinished art.
A sane mad man in a world of sane madness.
Find the curious mural.
Find the Pool.
Find out the fate of the couple of lovers.
Read 10 letters, notes or journals.
Reach the Mining Town.
Something lurks in the darkness...
Hopefully the last one.
You unlocked access to the mines.
Repair 10 facilities.
Find or craft an high quality tool.
Open your first shortcut.
Survive 1 day in the game (any difficulty)
Find a Dead Viscacha
Move on from the crashsite.
Wake up in the Atacama desert.