How do rivers create deltas

When a river flows into a lake or ocean, its speed slows down, and it starts dropping the sediment it was carrying. Over time, these sediments pile up and form a delta—a landform that grows outward into the water.

🔹 Why does this happen?

As the water slows, heavier particles like sand and gravel settle first, while lighter ones like silt and clay drift further out. This creates layers of sediment, with sloping layers building outward into the lake.

🔹 What does this look like over time?

With more and more sediment, the delta keeps expanding. You can often see sandy, sloping deposits near the river mouth and finer mud deposits spreading further into the lake.

Deltas are fascinating because they shape landscapes, provide habitats, and even preserve records of past climates!