30 Days of World Building gives this as the exercise for Day 8.
It really boils down to:
1. Mark resource areas on your map
2. Check your timeline for pressure points caused by resource needs
3. Which groups care about which resources?
The Emptyland (brown) is only useful as an empty, unoccupied land. That's why The Movement is relocating Sourcerers there. The town on the northern shore of the Great Inland Sea is where they are being brought. I'll need to flesh this out more.
Fjordland has great mineral wealth and easy to get to. It is for that reason that the Great Old Empire had established a trading relationship with those people. That trade ended when the GOE trading fleet was destroyed 100 years ago when the Comet hit. The Fjordlanders have felt the pinch of that lose of income. They were being terribly exploited by the GOE who did not give them fair prices, but some of the people who were making the most money out of it are still looking for ways to replace it. Some have turned to piracy, but there is little trade to raid. Most have sought other markets and the Golden people are buying.
Fjordland also has a wealth of trees, but that is being squanderd because it is being used on building high quality boats. There aren't enough trees to export, but no one is buying anyway.
GREAT OLD EMPIRE
The GOE started on Orangeland originally. Orangeland was good farmland and had many domesticatable animals, but lacked mineral resources. Early in their history they expanded to Yellowland which is richer in gems and precious metals, but lacking in stones appropriate for building. Between the resources of the two islands the GOE developed an unequalled porcelain industry. Their fine porcelain is traded and highly valued. The construct many things out of different qualities of bricks and porcelain. The two most important resources they didn't have were building stone and Magic.
Magic seems to be a byproduct of the alien originated races and so it is absent from the people of the GOE. They never really needed it when they didn't regularly encounter magical people. They substituted community. As they started dealing with the Fjordlanders, who have rudimentary magic, they realized the value of magic. In their dealings with the Golden people they are convinced that they need magic in order to compete with the Golden people. They are willing to go to war to get it, but they aren't quite strong enough to lead an offensive war unless some great leader shows up to lead them.
When the Comet struck in 2500EG the GOE took a great hit. They contracted their borders to west of the crater on Yellowland and north of the crater on Orangeland. A good deal of farmland was destroyed and a great number of their population. They haven't quite equaled out and there is barely enough farmland to support the population. On Elorih only the GOE is overpopulated.
On Wispolil (the purple land) There are quite a few things going on. Basically the continent is divided into Goldland, Forestland and Desertland.
Goldland has some precious metals, huntable animals and productive grasslands. The greatest resource of Goldland is Magic. Only Golden people produce pure Sourcerers. They have fought over this resource among themselves for hundreds of years, but recently it has become a valuable commodity outside of Goldland.
Forestland has, of course, trees. The Forestlanders carefully harvest their trees. They don't cut down whole, mature trees unless as a last resort. They try to harvest the fruit, leaves and even limbs without taking whole trees. They do not export lumber, even though they have an abundance. Their greatest export is technology and science. Sourcerers born to Forestlanders are usually less autistic and less powerful magically. They are always abducted by the Klelryn.
Desertland's greatest resource is transportation technology. The Desert people developed airships (ships that fly with wings), dirigibles, balloons, sea ships, sand ships and caravans. They are the world's great traders. They like nothing better than their freedom, but they also like good food, wine and company. They charge very little for their transportation services, just a small percentage and the freedom of being left alone.
I've made a few edits from earlier posts based on this work.