Resources
Lakes produce Food. The higher lvl the lake the higher the % of Food it gives.
Mountains produce Ore. The higher lvl the lake the higher the % of Ore it gives.
Grass produce Food. The higher lvl the lake the higher the % of Food it gives.
Woods produce Wood. The higher lvl the lake the higher the % of Wood it gives.
Hills produce Stone, The higher lvl the lake the higher the % of Stone it gives.