Posted March 01, 2021 by Robin Johansson
Lakes are an important part of terrain generation. They "patch" holes, enabling water to reach all the way to the ocean without getting stuck. Lakes also pays a huge role when ecosystems are to be simulated, without them certain plants and animals couldn't exist. For the player both freshwater and saltwater lakes would be useful. Freshwater lakes could provide a valuable source of freshwater and fishing, whilst a saltwater lake would enable cheap production of salt through lake water evaporation.
In general, lakes can be divided into two categories: open lakes and closed lakes.
Closed lakes are lakes where the inflowing water balances out evaporation, thus the lake does not drain. Lakes which do not drain tend to accumulate minerals, thus their water is brackish or salty. An example of a real world closed lake would be the Caspian sea in the middle east.
Open lakes are lakes where the inflowing water exceed evaporation. Thus excess water drains from the lake into new or existing rivers. Since water drains from the lake they tend to contain freshwater. Examples of real world open lakes are the Great Lakes of north America, which drain into the Atlantic ocean.