Physical Geography

Land. The Netherlands occupies part of the Great European Plain and is predominantly flat. In most places, the surface consists either of glacier-deposited sand, gravel, and clay; or of silt laid down by rivers since the last Ice Age. Roughly half the land lies below sea level; the rest rises only slightly above the sea, rarely to more than 300 feet (90 m). Large parts of the country consists of land that has been reclaimed from the sea.

Sand dunes fringe the North Sea coast. In places, this sandy belt is breached and broken into islands—the West Frisians in the north and the delta islands of Zeeland in the southwest. Behind the dunes lie lowlands and polders (drained land lying below sea level). With its dikes, canals, and windmills, this is the area that many people picture when they think of the Netherlands.

Eastern Holland is a flat to gently rolling region. Most of the higher parts are morainic ridges and mounds left by glaciers. In the extreme south, in a tongue of land wedged between Germany and Belgium, is the plateau area of Limburg. Here Vaalserberg, the highest point in the Netherlands, rises to 1,056 feet (322 m).

Crisscrossing the land are many rivers, canals, and drainage channels that interconnect. In some areas, waterways flow in embanked channels above the level of the adjacent land.

The Rhine (Rijn, in Dutch), Meuse (Maas), and Schelde, Holland's three chief rivers, flow to the North Sea through a delta area in the south. They reach the sea by numerous distributaries, or branches. Among them are the Waal, Neder Rijn, and Lek for the Rhine; the Bergsche Maas for the Maas; and the Wester Schelde for the Schelde. The delta area, which extends into Belgium, is one of the world's great hubs of international commerce.

To protect against disastrous flooding, such as that of 1953, enormous concrete barriers with movable gates to control sea and river water levels were built in the delta channels as part of the Delta Project. After nearly 30 years of construction, the project was completed in 1986.

The largest lake is IJsselmeer, created in 1932 by construction of an enclosing dam that blocked out the North Sea's salty water, making it into a freshwater lake. Into it flow numerous small rivers and the IJssel, which carries water diverted from the Rhine. The dam was built as part of a land-reclamation project. Four polders—Wieringermeer Polder, Noordoost (Northeast) Polder, Oostelijk (Eastern) Flevoland, and Zuidelijk (Southern) Flevoland—have been drained. One more, called Markerwaard, is being developed.

The Netherlands has a maritime type of climate similar to that of the coastal areas of Washington and Oregon. As in most of northwestern Europe, weather is conditioned mainly by westerly winds that bring inland the tempering effects of the North Atlantic Current. Summers are cool, winters are normally mild. Average temperatures range from about 62° F. (17° C.) in July to about 35° F. (2° C) in January. There is much foggy, damp, and rainy weather, especially during fall and winter. Average annual precipitation is about 35 inches (890 mm).