A geographical phenomenon known as a delta is formed at the mouth of a river where it meets a larger body of water, such as an ocean or sea. Deltas are created by the deposition of sediment carried by the river as its flow velocity decreases upon entering standing water. This results in the development of unique ecosystems and rich biodiversity, providing habitats for various wildlife species. Deltas play a crucial role in supporting agriculture due to their fertile soil and are often densely populated human regions due to their resources, making them significant for both ecology and human activity.