Large peat bog polders in the delta

The Netherlands consists largely of the connected delta area of the rivers Rhine, Maas, and Scheldt. Their mouths, which have mostly been widened into estuaries by tidal action, are located in the provinces of Zeeland and South Holland. Most river branches did not directly flow into the open sea but filled the marshy lagoon behind the Dutch beach ridge, a series of dunes and sand ridges that separated the land from the sea. In these marshy lagoons, grasses, plants, and shrubs grew luxuriantly. When they died, the plant material sank to the bottom and formed peat. Later, during flooding from the river or sea, a layer of clay was often deposited on top. Hence the name low-peat polders.

Dromos