"These green lands dotted with small lakes are a good place to establish a large colony capable of housing a multitude of colonists. There is not much vacant land, so you will have to take advantage of each free space to expand the colony. Furthermore, it is not a region rich in minerals or iron, although it is rich in food, which will allow you to create a large army to fight against the swarms of infected who roam around the lands."
This map is considered to be arguably one of the most difficult missions in campaign.
The map is very small (100x100 tiles; for comparison, regular survival mission maps are 4 times bigger, having 200x200 tiles). As a consequence, runners and Executives spawn twice as close than usual.
It's good to postpone this mission until beating a few difficulty 3 missions. Command center upgrades, Great Ballista and iron transportation are must-have, as every step of expansion takes high risk.
Place your first ballista at the west of the command center, right next to it. If being placed too far away (even 1 tile away), it will keep firing and eventually attract a horde.
Center of the map has slow infected and relatively big area suitable for housing, so it should be a priority for expansion. Don't push west; executives can already be pulled by noise near western rock.
Carefully place ballistas around, prepare an army of soldiers, then fire at north-east and retreat behind walls.
You will likely be forced to face and kill 80%~ of infected on the map during the first swarm. After that everything gets much easier.
Note that you don't need to resist all swarm to win this mission. After clearing out the map, guard all choke points and focus on colony population.