why not
A transportation barrier is a natural barrier like mountains, rivers, oceans, etc that blocks or slows the way of transportation.
because they form a natural barrier
There are many types of animals that live in rivers. Raccoons, snakes, fish, frogs, platypus, and otters are all animals that stay in the rivers.
aquatic animals
Drought
Drought
It is a natural feature
Rivers belong in the physical realm, but may also be shown on a political map.
An ecological barrier is a natural or human-made feature that restricts the movement of organisms across a landscape, such as mountains, rivers, roads, or urban areas. These barriers can hinder gene flow, change habitat connectivity, and impact the distribution and diversity of species within an ecosystem.
Fish.
Rivers,mountains, and valleys are examples of physical features
A map drawn or printed on paper is a physical map.