Why are parts of the Mekong River delta swampy?

Parts of the Mekong River delta are swampy primarily due to the region's low-lying topography and poor drainage conditions.12

In the middle section of the delta, there are areas that are poorly drained, leading to the formation of swamps. Additionally, the area north of the Ca Mau Peninsula is characterized by its swampy and forested nature.1

Generally, swamps form in regions of low relief where water supply is sufficient to keep the ground waterlogged and drainage is inadequate. In deltaic environments, sediment is deposited by the river, and in areas between distributary channels—known as interfluve zones—fine-grained silts and clays accumulate. When these areas lack sufficient drainage or are subject to seasonal flooding, they become waterlogged, creating the conditions necessary for swamp ecosystems to develop.23