Delta

A delta is the landform that results where a subaerial channelized flow (e.g., a river) enters a basin of standing water (e.g., the sea, a lake). In deltaic areas, flow velocities drop and sediment transport stalls, which results in bifurcation of rivers, a downstream widening of floodplains, and the buildup of deltaic plains that make the coastline protrude. Many deltas have become densely populated today. Industrial and urban uses of deltaic areas must deal with issues of flood hazard mitigation.

The word delta resembles the character “Δ” in the Greek alphabet. Its shape mimics that of the largest delta known in ancient Greece (that of the Nile River in Egypt as viewed from the north). Deltas come in many forms, and the term is used in ...