Urban flooding response: Netherlands-master against flooding

Urban flooding response: Netherlands-master against flooding

Can say no other country in the world has the prevention of flooding and more effective than the Netherlands. This country even established the water Board has independent role than the local authorities, professional treatment.

Thousand of years of treatment cards

The flood threatened area of the Netherlands is basically an alluvial plain, formed from sediments due to thousands of years of flooding. About 2,000 years ago, most of the territory of the Netherlands covered by extensive peat bogs. Coastal sand dunes creates natural embankment to keep the Marsh not drifted out to sea. The appropriate area to stay is on the high ground to the East and South, on the dunes and natural embankment along the coast and rivers.

In some places, the sea broke the embankment, flooding wide areas created in the North. To protect the Dutch House was built on artificial hills called terpen or wierden. The first Jetty was built just on the lower 1 m surrounded rice to protect crops against flooding. About the 9th century, sea-level rise up and several terpen to be raised to stay safe.

Several terpen combined together into the villages and are connected by the dike. After the year 1000, the population increased dramatically, need more than land to farming and there are also many more resources to treat. In 1250, most Online topics are connected together, become a coastal defensive dyke system.

Construction of the dyke methodology changed over the centuries. Popular in the middle ages is the method “wierdijken”-dike embankment by ground with layers of protection by seaweed. People build levees by land, then take the seaweed stacked outside.

The process of compression and rotten seaweed form solids so effective in resisting the impact of the waves. In places there are seaweed, people used Reed or Willow. People also use a kind of dike is the wooden dike, embankment soil below. However, this is often a kind of dike type HA eat corrupt. After that, people have to use stones to replace but very expensive, by the Netherlands no more stones, are imported.

Currently, the levees are made of sand core, external coated with thick clay for waterproofing and erosion. People also use a layer of gravel below the draught to reduce the power of the waves. Up to the high water levels, topics are usually covered with basalt or tarmac. The rest is covered by grass and maintenance by dropping of sheep. Sheep weeding more dense and adherent to the ground.

In parallel with the construction of the dikes, the Dutch also dug the Lake against flooding. People dig the drainage ditches to water from farmland areas in the water reservoir. The water is then pumped into the canal system another to lead forth the larger Lakes and so on until the sea. Previously, people used windmills to take water from this reservoir to the other reservoirs, pumping stations, today replaced the role of the Windmill.

River flood control

3 major European rivers include the Rhine, Meuse and Scheldt rivers are flowing through the Netherlands, where the Rhine and Meuse river flowing horizontally from East to West. The first major construction work on the River was conducted by the Romans. The levees of the river appeared near the mouth of the River in the 11th century, where the waters flow into the sea can increase the danger because the water level of the river.

However, the dams in the River to prevent floods spilling into the land, but causes problems for people living in the river. Large scale deforestation in the upstream water level makes the river becomes more extreme, while demand for arable land led to the construction of several dikes to protect the space, making the River less travelled, as do the water level higher.

The dike protecting villages to be connected together to create a huge mess with levees prevent river water all the time. This means that if the dike breaks, the flood will be devastating. 17th and 18th century happened much the river flood damage.

In 1977, a Commission has warned the weakness of the levees of the River, but met much resistance from the local population against the demolition of houses in order to strengthen, upgrade of the dike. Have to come at the battle of the flood of 1993 and 1995, when more than 200,000 people have been evacuated, people approved of the new renovated the levees of the river. To date, the risk of flooding of the river has declined from 100 times in 1/1,250 years.

The levees and water control structures were first built and defended by those who directly benefit from them, mainly farmers. When the works on as more and more complicated, the Council was set up from the people who have a common interest in controlling water, from which the water Council. Until the mid-20th century, there were about 2,700 Assembly water water in the Netherlands.

Today, after several mergers, the remaining 27 water boards. The Council has a separate election mechanism, tax collectors and independent activities with other government agencies. With good water-control ability, the Dutch can even create temporary flooding zones to prevent the penetration of a foreign State.

The modern works

The development of technology-engineering in the 20th century help works to prevent flooding of the Dutch increasingly larger and more efficient. In it, two of the most important works is the Zuiderzeewerken and the Deltawerken. Zuiderzeewerken-system of dams and drainage. The most important of which is the dam in the Zuiderzee, a large shallow Bay of the North Sea.

This dam named the Afsluitdijk, was built in 1932-1933, “separating” the Zuiderzee off the North Sea, the sea of Zuider became freshwater lakes Ijssel. The system helped the Dutch have 1,650 more km2 of land. This system was built from 1920-1975, the largest contributors to this work is the engineer Cornelis Lely.

Deltawerken is a series of construction projects in the southwest of the Netherlands to protect a large land areas in the plain of the Rhine-Meuse-Scheldt from the intrusion of sea water.

The works include dams, drains, embankments, and key barriers to storm waves. The purpose of the dams, drains, and the barriers was to shorten the Dutch coastline, thus reducing the number of dikes are built. Together with the society were Deltawerken, Zuiderzeewerken civil engineer declared the United States is 1 in 7 Wonders of the modern world.

Video: the Netherlands has created the greatest sea Dyke system planet