Zeb on rivers

A river, is a natural watercourse where freshwater travels along toward a body of water, such as lakes, oceans, and rivers. Water within the river is usually collected from springs, glacier melting, rain drainage, and snow melt. The water usually flows along the bed leading to the other body of water, though it tends to overflow which leads to flooding. Ecosystems usually are found all along a river.

Now imagine a river from today's world. Lets pick the Indus River which orginates high up in the mountains in Tibet. The river itself relies on runoff from the mountain during the spring. However, the Indus river loses most of its water during the winter, resulting in its "death" since there is little-to-none water flowing down the channel. This also results in the local river ecosytem receiving severe damage, if not complete destruction, due to the lack of water for the local organisms.

During the Spring, as it gets warmer, the snow begins to melt and the runoff goes into the dry river bed, resulting in the "rebirth" of the river. The ecosystems along the river again grow and spread. The local human population might use the water for irrigation also since it is also planting and harvesting season. The runoff continues through the summer, as the hot weather causes more snow runoff, and rainstorms. When the river dies in the winter, it will be reborn again in the spring.

Sometimes its not that simple, especially with the largest rivers in the world. For example, the Amazon River never seems to disappear because of its sheer size and the huge amount of rain that falls on the area all year around, further helped by runoff from the Andes during the spring and summer, the numerous rivers that feed into the Amazon river.

In summary, that is the "death" and rebirth cycle of a river. "Dies" in the winter or of a drought which does happen occasionally and is reborn during the spring from runoff or rain. This is a natural process that continues over the years, though recent human activity may have affected the life and "death" river cycle enough to have an effect in the future.