People Shaping The Land: Polders

 

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Geography Is Dynamic. Remember it, and remember it often. Things on the earth are changing all of the time. Many of those things are natural. Many things change because of human beings. One example is polders.

What is a polder? Land which has been reclaimed from a body of water. That is the short definition. It is like making new land out of the water. Draining a swamp, a lake, or the sea(you have to put a wall around a certain area if draining part of the sea). This done by engineering. The video below will give more details.

Land reclamation, the creation of polders, has often been necessary in places where an adequate amount of land was lacking. Human beings would shape the land by changing certain things about the land. In particular, what features are on the land. One example, a very famous one, is The Netherlands. Flevoland, the 12th province of The Netherlands, is a product of this process. Most of the land in Flevoland was only reclaimed in the 1950s and 1960s.  The land was reclaimed from IJsselmeer, a lake. It is home to the city of Lelystad, built in 1967, established as a city in 1980. Another example of Alemere, The Netherlands. This is the newest city in The Netherlands, becoming a municipality in 1984. Like Lelystad, it is located in Flevoland. It is built on reclaimed land. Today it has a population of over 196,000 people.

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Photo by Mark Ahsmann.

If cities like Lelystad and Almere can be created on polders, this leaves much to consider as far as other places that could be built out of land reclamation. Other cities have been expanded due to land reclamation, Singapore, San Francisco, Perth, Dublin, New Orleans, Boston,etc.

With the good comes the bad. Building polders has the advantage of creating more land. That land itself can also be a liability. This is land that was perennially under water. The soil will be very soft and unstable. One thing Singapore did to make sure the land would be stable by leaving the land unused for 20 years. This would give the reclaimed land enough time to settle. There is also the issue of the environment itself. A lake or swamp that existed before will disappear, and with that, the flora and fauna that would have been there. Many will see this as a bad thing, arguing that it would destroy a habitat. Some might see it as a good thing, particularly in the case of swamps. Some will argue that it would get rid of an environment that was poor for habitation.

However one looks at it, polders are an example of people shaping the land for a need. It is geography showing itself to be dynamic. The land changing. In this case, via people.

Floodplains

It is spring in North America. This means the snow is melting. In many places, the snow never comes. As the snow melts, the creeks and rivers will expand. What does this result in?

Floods!! Yes, that raging river bursting past its banks and causing many problems. However, one cannot talk about floods without talking about floodplains.

What is a floodplain? This is a low lying area along a river. Whenever a river reaches beyond its normal levels, and has a high discharge, that water has to go somewhere. In that case, it is going to expand to some low-lying land known as a floodplain. In a nutshell, it is a plain for flooding.

Animation below shows how a flood plain works.

Stay tuned for more on flood plains.