What is the purpose of an indicator?

An indicator is good to see what something's pH level is. (To see if it is an acid or a base.) 
Hope this helped! (:

1. Geography affects the settlement of future civilizations when taking into account the resources provided in different areas. Lusher areas with a larger range of edible plants and animals as well as water are a very appealing location to start a settlement. Of course, different groups of people with different lifestyles will be searching for varying resources to start their society, or to just stay temporarily if they choose nomadic existence.

2. Climate majorly affects settlements depending on if they want to grow crops, as well as the type of crops. Another factor dealing with climate in relation to settlements is if it is a bearable climate to live in long term without higher death rates due to temperatures.