For a front to occur, two different masses of air need to collide with each other.
<u>Explanation:</u>
The fronts formed by colliding air masses are literally the zones of transition where two air masses flowing towards each other meet and stop each other from gushing further horizontally.
These colliding air masses are generally warm and cold in nature.
The cold air masses usually flow from temperate zone towards the tropical zone, whereas, warm air masses flow from the tropical zone towards the temperate zone.
In south and southeast Asia humans commonly modify and interact with there water environments by the fishing, building dams and rearing of fishes in the form of aquaculture.
Building bridges is not their priority as they are interested in food and energy supplies.