Wedding

A country below sea level. Holland - reclaimed from the sea

"Lower Land" - this is how the name of the small European country of the Netherlands sounds in translation from the Dutch language. Officially, this state is called the Kingdom of the Netherlands, as it is a hereditary constitutional monarchy. Often the Netherlands is called Holland, which, in principle, is wrong, because only two provinces of the kingdom are called Holland (North and South). True, these are the most economically developed provinces in the Netherlands.

The Netherlands is a maritime country whose lands in the west face the North Sea. It is noteworthy that about half of the entire territory of the state is slightly lower than sea level. Actually, that's why they call the country "Lower Land" or "Low Lands". The industrious Dutch "recaptured" the land from the sea, building a rather complex system of dams, dams and canals. Such lands, which were once the seabed, are called polders. In the second half of the 20th century, the Dutch carried out a grandiose project called the Delta Project. Amazing in its engineering solution, the system of locks, barriers, dams and dams was recognized by the international community of hydraulic engineers as truly unique.

The Kingdom of the Netherlands is the most populous country in Europe. About 17 million people permanently live in a relatively small area, cut by rivers and canals. It is not surprising that almost every piece of land is rationally used: either for building, or cultivated for growing any crop. Quite a lot of land is allocated for the cultivation of flowers, the sale of which to many countries of the world is a significant part of the Dutch budget.

The Netherlands is rightly called a tourist country. Every year it is visited by millions of tourists from all over the world. There are so many natural and architectural attractions in the Netherlands that they are enough for several countries. Perhaps, first of all, people pay attention to an integral part of the Dutch landscape - the famous windmills, some of which have been working properly for 300 years.

Without exception, all the cities of the country have many cultural and architectural attractions, monuments, museums. First of all, this applies to the capital of the country - Amsterdam. The historical center of the city, which occupies a fairly large part of the urban area, is surrounded by a network of large and small canals, through which about 1200 bridges are thrown. The famous Amsterdam museums, including the Van Gogh Museum, the Stedelijk Museum with interesting expositions, the famous Rembrandt House Museum, the Rijksmuseum, are always full of visitors. Walking through the streets of Amsterdam with visits to shops, studios, cafes and the Red Light District can add some "zest" to Dutch travel.

The Hague is the unofficial capital of not only the Netherlands, but also the European Union. It is in the beautiful The Hague that the buildings of the Parliament of the country, the government quarter, the residence of the Dutch monarchs, the headquarters and offices of European and international organizations are located.

Rotterdam is the second largest city in the Netherlands after Amsterdam and the largest port in Europe. The most famous historical and modern sights of the city, such as the Euromast observation tower, the Erasmus Bridge, the seaport and the cube houses in Rotterdam, are visited annually by several million tourists from all over the world.

Maastricht is the oldest city in the kingdom, whose fortifications were built during the reign of the Roman Empire. The remains of these fortifications can still be seen on the banks of the Meuse River, and in the city center you can admire the architecture of the ancient churches of St.

The city-museum is the ancient Utrecht, whose history goes back more than 1000 years. The city is notable for the fact that it was in it that the formation of the Dutch Republic was proclaimed in 1579. Other major cities of the country can boast of their sights: Haarlem, Delft, Leiden.

The Netherlands is very original and picturesque, so traveling through this amazing country will not leave anyone indifferent.

The sovereign countries listed here are different from others. The main criteria for difference are either natural conditions, or demographic characteristics, and somewhere even tourist features.
Country-continent - Australia

Almost every continent has more than one country except Australia. Australia is the only country in the world that is a continent and the only continent that is a country. The area of Australia is 7,686,850 sq. km, making it the sixth largest country in the world. This country-continent is slightly smaller than the US, but 31.5 times larger than the UK.

Most unvisited country - Tuvalu

Tuvalu is one of the smallest countries in the world. It is located between Australia and Hawaii. Experts predict that Tuvalu will be the first country to be flooded when global warming raises sea levels high enough. In addition, it is very difficult to get here, and flights from Fiji are very expensive. Thus, only 1100 tourists visit Tuvalu every year.

Country below sea level - Netherlands

Surprisingly, approximately 50% of the Netherlands is below sea level. It is on these lands that more than 60 percent of the country's population (15.8 million people) lives. Only in the south of this state the level above the sea rises by 30 meters or more.

The most endangered country - Ukraine

Ukraine is the country with the lowest birth rate, and the natural population decline here is 0.8% annually. According to forecasts, Ukraine will lose approximately 28% of its population by 2050. If at present the number is 46.8 million, then in 2050 this figure will be 33.4 million people.

Country in the jungle - Suriname

91% of the territory of Suriname is covered by forests - this is 14.8 million hectares or 57 thousand square meters. miles. Low rates of deforestation here are due to vast and impenetrable forests, as well as a small population - about 400 thousand people. Almost the entire population lives in the capital or coastal cities, and only 5% of the population lives in the rainforests - these are indigenous peoples and six tribes of blacks.

Country with the smallest population density - Mongolia

The population density in Mongolia is approximately 4.4 people per square mile or 1.7 per square kilometer. Mongolia's population of 2.5 million lives on over 600,000 square miles of land (about 1,560,000 sq. km). Most of these people are in urban areas, as the development of pastures in the deserts of Mongolia is difficult due to drought and frequent dust storms.

Desert Country - Libya

Libya is the country with the highest percentage of desert - 99 percent. The Libyan desert is also the driest place on earth. Some places can remain without rain for decades, and even in the highlands it rarely rains - once every 5-10 years.

Country with more than 17500 islands - Indonesia

The entire territory of Indonesia consists of more than 17.5 thousand islands. The length of the full coastline is 81,350 km. The largest islands here are Java, Sumatra, Borneo, Sulawesi, Bali, Lombok and Flores. Approximately 6 thousand of all the islands are inhabited. In addition, Indonesia contains 10-15 percent of the world's coral reefs.

Country with 3 million lakes - Canada

More than 60 percent of the world's lakes are located in Canada. There are so many reservoirs here that even their exact number is still unknown. In some areas, for every 100 sq. km there are more than 30 lakes.

BELOW SEA LEVEL

“Throughout the summer, the Sun was hiding behind the clouds, as if it no longer wanted to look at the Earth. Eternal silence reigned on Earth, and a damp fog, like a wet sail, hung over the dwellings and fields ... Then the earthquake began, as if foreshadowing the end of the world ... The rivers changed their course, and new islands of sand and sediment formed at their mouths. This went on for 3 years, and then calm reigned, and forests reappeared. Many countries have disappeared under water, in a number of places new continents have appeared. This is how the book of the Frisians "Hurrah Linda Book" tells about one of the terrible catastrophes that occurred in the early medieval period on the shores of Northwestern Europe.

The memory of the ancient Frisian tribe (by the way, 400 thousand of their descendants still live today) was reflected in the names of the Dutch province of Friesland and the chain of eastern and western Frisian islands, which stretch in a straight line almost parallel to the coast of the North Sea. These islands are also a memory, a memory of the fact that the land border was still in the 1st millennium AD. went much further north.

It is unlikely that there is another area on our planet where, in a relatively short period of human history, such sharp turns in the fate of the earth and sea would take place. So far we have been talking about fluctuations in the earth's surface within individual sunken or sinking cities. Here, in the northern part of Europe, the changes covered the territories of several countries at once, from England to Finland.

At the time of the first Egyptian pharaohs and the Sumerians, the British Isles did not yet exist, there were no straits of the Pas de Calais and the English Channel, and the whole of Northern Europe had a look different from the modern one. Only in the III millennium BC. finally separated from the mainland of the island of Britain. The North Sea flooded the low-lying regions of Northwestern Europe.

But the land did not give up. The sediments of numerous rivers and marine deposits created the Netherlands, almost the entire territory of which by the 1st century. AD (i.e., by the time, for example, the heyday of the Bosporan kingdom) was a huge swampy lowland with a large sea lagoon in the northwestern part.

Of course, the rivers could not cope with the sea element alone. They were helped by a happy combination of the prevailing wind directions and two high and two low tides alternating during the day. It was they who created an amazing structure of northern European nature - the dunes. Wind-blown sandy hills 10–30 m high (up to 60 m) and up to several kilometers wide formed a protective dam, separating the Netherlands from the sea and protecting the country from flooding.

Geomorphologists distinguish between two types of dunes. One of them, the so-called old dunes, formed in prehistoric times in the west of the Netherlands from sandy ramparts, parallel to the current coastline. New dunes (higher ones) were created by nature in the 9th–11th centuries. Some of them rise on the old dunes, others are located to the west.

Behind the old dunes within the former lagoon, specific types of soil were formed in due time. Firstly, these are marine clays applied by sea water penetrating through the open space between the dunes. Secondly, these are peat layers that formed as the lagoon became shallower.

So, at the end of the 1st millennium AD, when many ancient ancient cities of the Mediterranean were already swallowed up by the sea, a new land area arose on the southern coast of the North Sea, which began to be quickly settled and developed.

In the 7th-10th centuries The sea began to take revenge. At the beginning of the 2nd millennium, its offensive assumed gigantic proportions and a catastrophic character, as reported by the legends of the then inhabitants of the Netherlands.

On All Saints' Day 1170, the tide tore off the current Frisian Islands from land. By 1290, the water reached Lake Lying far on the continent. Flevo and, having flooded the lands where about 50 thousand people lived (according to legend, so many died), formed a new bay of the North Sea - the Zuiderzee.

The advance of the sea continued in the XIII-XIV centuries. As a result of the floods of 1218, 1287 and 1377. on the northern coast, another new Dollart Bay and, almost simultaneously, the Lauwers Bay appeared. Medieval chronicle of the 15th century. continues to report new forays of the sea. On St. Elizabeth's Day 1421, it swallowed up 65 villages. For a long time, Dutch fishermen thought they could hear the bells of sunken churches.

By the end of the Middle Ages, the southwestern part of the country again turned into a sea lagoon, among which individual islands rose. So they were named - Zeeland, which means "land of the sea."

In the continuous struggle between sea and land, the present-day Netherlands (“low-lying lands”) has developed, 27% of whose territory is, figuratively speaking, under water, i.e. below sea level. By the way, 60% of its total population lives in this part of the country. The lowest point (-6.7 m) is in the north of Rotterdam. The rest of the Netherlands is also not very high: more than half of it is located no higher than 1 m above sea level, so even the smallest surge of water can flood it.

The sea not only constantly keeps the Netherlands under the threat of floods, it cuts deep into the land itself with its bays. The total length of the country's coastline reaches 1075 km, which is more than 3 times the length of the Dutch territory in a straight line from the most southwestern point to the most northeastern and 8 times its width.

True, in addition to the lowlands, there are also the elevated Netherlands. This is the southeastern and eastern part of the country, where there are even their own "mountains". The highest point of 321 m above sea level is located in the extreme southeast. In the middle part of the Netherlands, in the provinces of Utrecht, Overijssel and Horderland, small hills called Stevwallen run from north to south. The Dutch value them so much that they do not populate and do not build up, but use them as a recreation area. The entire territory with heights over 50 m in the Netherlands is only 2% of the total area of the country.

"Deus mare, Batavus litora fecit" - "God created the sea, and the Dutch created the shores", as the old Dutch proverb says. Even in ancient times, the inhabitants of the coast realized that in order to survive, they must fight the sea. After all, nature has not finished its undertaking. The dunes did not stretch everywhere along the coast, they only partially protected the land from flooding, they gaped holes through which the sea constantly broke into the low-lying Netherlands.

The first thing that the ancient Frisians began to do was to build dams in the gaps between the dunes. “Around Friesland,” it is written in a legislative act of the 13th century, “everywhere where the salty sea waves, dams, one exactly like the other ... We Frisians will protect this land with triple weapons: a shovel, a spade and a wheelbarrow.” And in the Sakeon Mirror, compiled in 1230, it was said directly: whoever does not want to build a dam, there is no place behind the dam. The medieval coat of arms of Zealand even featured an image of a lion fighting the waves.

Dams were easy to build. Clay soil was brought in wheelbarrows, placed between the dunes and carefully compacted. The outer slope of the dam was reinforced with riprap or masonry. Sandbags were also used for shore protection. Often the coast was protected by grass cover, shrubs and trees, which have survived to this day. The width of the dams in a number of places reached 100 m, and the height up to 15 m (the average height of the dams is 7 m). The most intensive dam building captured the northwestern and northern shores, which were protected by an almost continuous belt of earthen dams, adjoining the dunes.

Dutch hydraulic engineers already in the 13th century. not only defended themselves from the sea with dams, but also advanced on it, drained the lands fenced off by them. So, for the first time in history, the concept of a polder appeared - a piece of land fenced off by dams and drained by pumping water and dumping it into the sea (Fig. 84).

The drained lands of the polders are usually indented by parallel horizontal drains, which in our time are increasingly being replaced by the closed tubular drainage described above. This makes it possible to organize the agricultural development of drained lands - the laying of transport routes, agricultural work, harvesting, etc. Drainage drainage removes excess water from the soil and diverts it into a collector, which is laid along the dam. A drainage well is built in a certain place, from where water is pumped out. In ancient times, windmills were used to operate pumps. Over time, windmills were replaced by steam engines, then diesel engines, followed by electric pumps.

At first, the dimensions of the polders were very small. Firstly, because there were no earth-moving and building mechanisms (everything was done by hand, and there were few of them in rural communities, and it was difficult to make a lot of them), and secondly, windmills had low power, and hence pumps for pumping water had little productivity.

Drainage work took on a particularly large scale for its time in the “golden” for the Netherlands in the 17th century. As a result of the pan-European Thirty Years' War, according to the Peace of Westphalia (1648), the country finally gained independence, a de facto republic of the United Provinces was created, and manufacturing began to flourish. The Netherlands acquired numerous colonies in Southeast Asia, South America and Africa. “Exemplary capitalist country of the 17th century” - this is how K. Marx called the Netherlands of that time.

Rice. 84. Scheme of polder drainage

a - plan; b - incision;

1 - dam; 2 - drains; 3 - pumping station; 4 - drainage and discharge channel (reservoir)

The rapid development of trade and industry led to an increase in population. Such large port cities as Amsterdam (already in 1650 there were 150 thousand people), Rotterdam and others grew up. Accordingly, agriculture began to develop, which required more and more new lands. Dozens of new polders appeared on the site of former lakes in Holland, Friesland and other provinces. In the XVI century. 710 km 2 of lowland lands were drained, in the 17th century. this figure reached 1120 km 2, and in the XX century. it is 2500 km 2. Today, half of the entire land area of the Netherlands (the entire west and part of the north) is artificially drained land (Fig. 85).

The first large polder (Gaarlem) was built near Amsterdam according to the project proposed by the engineer Legvatter in 1641. Lake Gaarlem was formed in the 16th century. by the confluence of several small lakes and threatened to flood Amsterdam itself.

For 13 years, the Gaarlem polder was built. Tens of kilometers of earth dams were erected and hundreds of kilometers of drainage ditches dug. So, in the middle of the XVII century. near the walls of the rich Dutch city of Gaarlem, instead of the inland sea, a new agricultural region arose.

Rice. 85. Drainage works in the Netherlands

1 - land drainage in 1200–1600; 2 - land drainage in 1600–1900; 3 - land drainage in 1900–1970; 4 - promising land for drainage

Nowadays, the landscape of the Netherlands is unthinkable without polders. There are hundreds of them, large and small, peat and alumina, low and high. The record of deepening below sea level was broken by the polder of Lake. IJssel - 35 m. Polders, formed as a result of the drainage of lakes, are located at a depth of 6–7 m below sea level. Many polders were created on the site of former peat extraction, they lie about 1 m below sea level. However, there are polders that are several meters above sea level - these are drained areas in floodplains. Here, pumps are not even needed to drain water - it flows by gravity into the outlet channels through locks - water outlets that open at low tide. There are many such polders in Friesland and Groningen.

Drained lakes and other polders located far from the sea or river usually have two ring dams, between which a diversion channel is placed. The pumped water has to be discharged into this channel, and not directly into the sea or river, as in coastal polders. On lake polders, in addition to channels in the drainage system, there may also be intermediate regulating tanks: reservoirs or reservoirs that accumulate drainage water and periodically discharge it into the sea or river.

Maintaining a certain level of groundwater in the polders is carried out automatically. If it starts to rise above the permissible level, sensors installed in drains or directly in the drained soil are triggered, the signal is transmitted to the pumping station, and it starts working. As soon as the water level reaches the desired level again, the pumps turn off by themselves.

Land draining is only half the battle. The development of polders usually takes many years. At first, it is absolutely impossible to build, plant, or simply walk along the bottom of the former sea or lake. Muddy soil cannot withstand the slightest load, spreads and absorbs everything that falls on it. Even after its consolidation and compaction (the settlement of the earth's surface reaches 0.5–1 m), which usually takes several years, buildings have to be built on piles at least 6 m long. During the entire period of development, work on the polders is carried out by the state, and only after that, the drained land is leased to farmers.

Speaking about polder drainage, one cannot remain silent about one unpleasant side result of many years of pumping out drainage water, which was not previously foreseen by anyone. This is an intrusion, an intrusion from below by salty sea waters, a process that was described above. It leads to soil salinization in polders and the death of agricultural plants. To eliminate the consequences of intrusion, the Dutch use methods of artificial replenishment of underground fresh water by free-flow infiltration of surface water through sandy soils in the dune area.

In the Netherlands, there is also a public service for the operation of polders, which originated in the Middle Ages, when each agricultural or urban community chose its own "dam keeper". There are more than 1.5 thousand polder supervision departments, their directors are chosen by the owners of land plots located within one or another polder - Ingelandens. The departments are subordinate to the provincial authorities and monitor the condition of dams, canals, pumping stations and drainage systems, sometimes the entire water management of the area, and also carry out activities for the protection of nature.

The most impressive victory of the Dutch over the sea is the implementation of the project of draining the entire sea bay - the Zuider Zee. Formed only a few centuries ago right before the eyes of the shocked population of the then Friesland, this shallow but vast inland sea has long been waiting for its conquerors. The first draft of its drainage was drawn up in 1667 by H. Stevin, who was inspired by the victory over Lake Gaarlem. However, at the time, this project seemed too bold.

The fundamental decision to drain the Zuiderzee, subsequently adopted for implementation with some changes, was proposed at the end of the 19th century. hydraulic engineer K. Lely. For 1.1 years, he conducted research for his project and even became the secretary of a special association. Lely proposed to build a wide protective dam connecting the coasts of Friesland and northern Holland. This dam was supposed to leave the sea only a small bay of the Wadden Sea, but the entire main part of the Zuider Zee turned into an internal lake. IJsselmeer. Gradually, the lake should be desalinated due to the fact that sea water will not enter it, and will begin to serve cities and industry as a source of water supply. The water reserves of the IJsselmeer should be replenished by the river of the same name flowing into the lake, the flood excess of which is discharged into the sea by two weirs built into a protective dam at its left and right shoulders.

The next stage of the plan for draining the Zuiderzee is the construction of five large polders off the coast of Lake IJssel with a total area of 2.2 thousand km 2, which gives an increase in the territory of the Netherlands by more than 6%. At the same time, the most fertile lands were intended for agricultural development (vegetable growing, floriculture).

At first, this Zuiderzee project was met with distrust, as the work on its implementation seemed too laborious and expensive. At that time, nowhere else had anyone built dams several tens of kilometers long or tried to cut off an entire bay from the sea. For almost a quarter of a century, the Dutch parliament, listening to the opinion of taxpayers, rejected the issue of financing the project.

Nature itself put pressure on public opinion: in 1916, the Netherlands was hit by a catastrophic flood with many meters of sea water surge. This was the last "drop" added to all the previous onslaughts of the sea and to a serious shortage of agricultural land and food, which was especially pronounced in the harsh and hungry years of the First World War.

The Zuiderzee drainage project has begun. At the same time, the sequence of work was somewhat changed. Construction work was launched not only in the area of the protective dam, but also in the sections of the polders. In 1927, near the northwestern coast of Lake. Eysell, a small experimental 40-hectare Andijk polder was built, which served as a model for another large section of polder drainage - Wieringermeer with an area of 20 thousand hectares, put into operation in 1930.

The construction of a protective dam that separated the bay from the sea and had a length of 30 km and a width of 90 m was started in six places at once. The lower part of the dam was first built during periods of low tide, then they began to fill the soil directly into the water. On May 28, 1932, after six years of intensive construction, the last gap was closed in a festive atmosphere and the Zuider Zee sea bay ceased to exist. A new lake appeared on the geographical map of Europe - the IJsselmeer, intended for subsequent drainage (Fig. 86). Somewhat later, in 1937-1942. a northeastern polder with an area of 48 thousand hectares was built with a center in Emmeloord. Its territory is located 4.5 m below sea level. Water is pumped out by three pumping stations, each of which has 8 centrifugal pumps with electric motors with a capacity of 4 thousand m 3 / h.

On April 7, 1945, a few weeks before the end of the war, the retreating German troops blew up the protective dam of the Wieringermeer polder and senselessly flooded it. After the war in 1950-1957. the largest polder was built - the eastern Flevoland with an area of 54 thousand hectares, the territory of which is buried 5 m below sea level. There are also three pumping stations for pumping water. Directly adjacent to this site is the fourth polder completed in 1968 - the southern Flevoland (43 thousand hectares) with one powerful drainage pumping station located near the northwestern dam.

Rice. 86. Drainage of the Zuider Zee

1 - coastline in 1920; 2 - dam; 3 - dam under construction; 4 - pumping station; 5 - mark below sea level; 6 - sluice-water outlet; 7 - permanent connection with the gateway; 8 - bridge; 9 - fresh water; 10 - salt water

Already the first years of operation of the northeastern polder showed the relevance of protecting the surrounding coastal area. The fact is that the intensive pumping of drainage water rather quickly led to overdrying of soils on adjacent lands. The lowering of the groundwater level spread to a large coastal area of Friesland, and the radius of the depression funnel reached several tens of kilometers. It was decided, despite the significant increase in the cost of work, to build polders surrounded by bypass ring channels. Therefore, the southern and eastern Flevoland polders do not adjoin the shore and are separated from it by a canal separated by a system of locks. This allows not only to quickly regulate the level of groundwater on the adjacent banks, but also to provide water transport in new ways.

Another negative consequence of the drainage of the Zuiderzee was the deterioration of fisheries. After the construction of a protective dam, which eliminated the bay, which until then was literally teeming with fish, many fishing villages were empty - there was nothing to catch. A particularly serious threat loomed over the famous eel, a unique fish; which, obeying some mysterious law, goes to spawn from here to the North Sea.

These and other environmental issues have now called into question the expediency of draining the fifth polder - Markervard, which was already under construction.

In addition, in the new conditions, new considerations appeared. Previously, the extensive nature of agriculture required more and more new areas. Under modern conditions, the intensification of agricultural production, the widespread use of chemical fertilizers, the success of plant breeding, and the creation of powerful agricultural machinery make it possible to obtain high yields even from a small area of agricultural land. Therefore, drained lands in the Netherlands are increasingly being used for industrial and residential development, organization of recreation areas, transport, energy construction, etc.

An example is the already partially completed construction project in eastern Flevoland of the large new city of Lelystad (in memory of K. Lely) with a population of 50 thousand inhabitants. Similar construction is planned for southern Flevoland, where the city of Almere will also serve to decompress the overpopulated northern part of western Holland. The new city will be adjoined by an industrial zone, recreational areas and nature reserves. There is a new, 12th province of the Netherlands.

Encouraged by success in the fight against the sea, the Dutch hydraulic engineers began to protect the territory from floods. Indeed, in the Netherlands there are the mouths of the three largest rivers in Europe - the Rhine, the Meuse, the Scheldt, and they behave far from calmly. In addition to the main channels, each of them has many channels and branches. Because of this, the total length of all watercourses in the Netherlands is a huge amount - 7 thousand km, i.e. 7 times the length of the country's heavily indented sea coasts.

On February 1, 1953, a terrible natural disaster befell the southeastern Netherlands: a catastrophic flood hit the entire area of the Rhine, Meuse, and Scheldt deltas. In a section of more than 100 m, water broke through the dams, 1,800 people died in one night, more than 40 thousand residential buildings and utility buildings were destroyed, an area of about 160 thousand hectares was flooded, losses amounted to 250 million dollars. This event accelerated the implementation of the Delta project, which was intended not only to prevent floods, but also to solve many other water management (including irrigation) and transport problems.

Immediately after the disaster of 1953, a collapsible dam was built on the Dutch IJssel east of Rotterdam, which could be quickly installed in the event of a flood. This barrage now protects most of the polders of the western Netherlands. After that, dams were built in the depths of the deltaic arms, and then on their border with the sea. In addition to protection from floods, as in the case of the Zuider Zee, the result of fencing off the delta from the sea will be the formation of reservoirs with fresh water. To this is added a significant reduction - the coastline: the distance between the extreme points A and B (Fig. 87) is reduced by 10 times - from 800 to 80 km, and the path from Rotterdam to Vlissingen is reduced by 40 km.

Rice. 87. Development of the delta

1 - dam; 2 - barrage for flood protection; 3 - channel; 4 - lock-outlet; 5 - the main transport highway; 6 - road; 7 - bridge; 8 - shipping lock; 9 - salt water; 10 - fresh water; 11 - dunes; 12 - flooded areas during the flood of 1953

Great work is also being done to improve the conditions for navigation on the Rhine. In its lower reaches, three water dams with locks were built. The easternmost of these allows part of the river's flow to be channeled into the IJssel basin. To concentrate all river flow in one channel, the waters of the Meuse and Waal are cut off from Haringvliet - the northern arm of the delta, and directed to the sea past Rotterdam, which makes the lower Rhine more full-flowing.

The Delta project foresees a significant increase in industry and trade along the new routes from Rotterdam to Antwerp and south of the Eastern Scheldt. The territories surrounding the delta, for example, the area of Rotterdam - the Europort, are also expected to be widely developed. Coastal agricultural lands also benefit - thanks to the appearance of large volumes of fresh water, soil salinization is prevented, which until now has been one of the constant concerns of Dutch flower and vegetable growers. In addition to the desalination effect, freshwater reservoirs will also give farmers a direct benefit - they will become a new source of irrigation.

By 1972, under the Delta project, which provides for the connection by dams of five offshore branches of the lower reaches of the Rhine, the Meuse and the Scheldt, most of the work had been completed. The northern arm has been turned into a full-flowing navigable canal, and at the same time the approach to the Rotterdam harbor has been improved. On the banks of the southern branch of the Western Scheldt, along the entire length of the Nieuwe Waterweg approach channel, old protective dams have been built or reconstructed to prevent flooding of the coastal areas of Antwerp in case of floods. The three middle straits were to be completely blocked by eleven deaf earthen dams, separating their water areas from the sea. Due to the cessation of the flow of sea salt water here and the passage of river flow, they gradually had to turn into inland lakes - reservoirs with fresh water that could be used to irrigate agricultural land and supply cities and industry. In addition, it was meant that the existing threat of salinization of coastal lands, a constant scourge of the harvests of Dutch farmers, would finally disappear.

Until 1972, seven of the planned eleven earth dams were built on the middle branches of the delta. In the first half of the 70s, a noisy environmental campaign began in the Netherlands, and many prominent experts and public figures opposed the implementation of the Delta project in full. It was also the fact that just at that time the traditional fishing of the inhabitants of the delta began to decline sharply - breeding and fishing for oysters, shrimps, mussels. Their development in this area is associated with special hydrological conditions, when, due to the constant intrusion of fresh salt water into fresh water, funnels are formed in the water, which promote the growth of juvenile fish and mollusks. The cessation of the sea tides changes the habitat conditions for many species of aquatic flora and fauna in the area.

Long and heated discussions led to the fact that in 1976 the Dutch Parliament passed a resolution to revise the Delta project.

As a result of the revision of the design solutions, it was decided to cut through the solid earth retaining dams of the middle branches of the delta with wide culverts. Through the Haringvliet dam (Meuse branch), 17 sluices-outlets with steel gates were laid, which will be closed only during floods. At the neighboring Browers dam, three bottom outlets were built in the form of tunnels 200 m long. Now, free water exchange is carried out between the estuaries of the Meuse, Scheldt and the sea during high tides. It was decided not to block the Western Sheld at all and limit it to the coastal protective dams mentioned above.

Especially a lot of objections were raised by that part of the project, which provided for the construction of a blind dam through the branch of the Eastern Schelda (Osterschelde) - the widest branch of the delta. The victory was won by specialists who considered it necessary to build here, although more expensive, but an environmentally sound system of culverts and barriers that block the flow of sea water only in extreme cases. This proposal was accepted and construction began, which lasted almost 10 years.

Rice. 88. Anti-storm barrier at the mouth of the Western Scheldt - a "comb" with 65 steel gates, each weighing 500 tons (This offshore engineering structure is one of the largest in the world)

On October 4, 1986, in a solemn ceremony in the presence of the Queen of Holland and representatives of many foreign governments, the opening of the protective structures of Osterschelde took place (Fig. 88). This completed the construction of the last object "Delta", which ended the thirty-year history of the implementation of one of the most ambitious projects of the 20th century.

To block the strait, which had a width of 9 km at the construction site, natural sandbars were used, which were turned into islands by dumping sandy soil. As a result, the strait was divided into three channels 2.5, 1.8 and 1.2 km wide.

The largest of these, Neeltje Jans Island, measuring 4x0.8 km, was used as the main construction site for the manufacture of 15 prefabricated hollow reinforced concrete bridge piers. For the manufacture of each of these supports - a pillar 40 m high and weighing 18.5 thousand tons, 7 thousand m 3 of concrete were used. In total, 65 reinforced concrete blocks-links were made, from which the supports of the dam were assembled.

These blocks were made in three special construction trenches at a depth of 15 m from sea level under the protection of earthen dams. The production of each part lasted about 1.5 months, several pieces were made at the same time.

After the supports were ready, the dams were broken and the trenches were flooded by the sea. Then, the pontoon U-shaped ship Ostreye (“Oyster”) floated into the passage in the dam to the construction site, which, using two 10,000-ton lifts, tore off the support from the bottom, fixed it with hydraulic shock absorbers and set off, delivering each support to its place.

The installation of supports, which were lowered to a depth of 25–30 m below the water level, was carried out mainly in calm sea conditions, although the Ostrea ship allows operation at a wave height of up to 1 m. The installation of reinforced concrete structures was carried out using 6 computer-controlled anchor winches and coastline orientation. The accuracy of the installation of supports on the sea bottom was 5 cm, the tolerances for fitting individual reinforced concrete structures did not exceed 1 cm. The accuracy of the installation was controlled using a laser device.

After installation on the bottom, the inner cavity of the supports was filled in the lower part with clay, in the upper part with sandy soil, which played the role of ballast and prevented the supports from floating under the action of the Archimedean force. The soil in the supports was compacted with vibrators. At the bottom, the supports were also covered with stone - boulders weighing up to 0.1 kN, brought from Finland, Germany, Belgium and Sweden, since there are practically no large stones in Holland.

Reinforced concrete supports on top were connected by hollow reinforced concrete beams. On the bottom of the sea, metal channels were laid between the supports, on which steel gates were installed, 42 m wide, weighing from 2.6 to 4.8 kN. The height of the gates is determined by the depth of the water during a given period of storm surge from the sea. The total number of shields is 62.

Lifting and lowering of the shutters, their removal to the side is carried out using hydraulic actuators. The operation to block all three straits takes 60 minutes.

Much and important work was carried out to strengthen the foundation of the structure. In its natural state, the fine sandy bottom of the sea, covered with silt, could not withstand the heavy loads from heavy supports. Compaction of the bottom layer of sand up to 15 m thick was carried out by four needle vibrators, lowered from the floating pontoon installation Mytilus ("Mussel"). A strip of the seabed 3 km long and 80 m wide was subjected to compaction.

The bottom leveling was carried out by a suction dredger mounted on another construction vessel Cardium (“Cormoidal Mollusk”), which moved along the dam site with a deviation from the course of no more than 0.5 m. It was equipped with 12 working bodies that leveled the bottom with an accuracy of 10 cm. A mat 42 m wide and 35 cm thick, unwinding from a drum, was laid in the bottom recess, which was like a mattress in the form of a mesh of artificial fibers filled with crushed stone. Another thinner protective mat 32 m wide was laid on top. A total of 130 mats were laid along the front of the water-retaining structures. Such strengthening of the bottom not only creates a solid supporting surface for the dam structures, but also reliably protects their base from erosion by bottom currents.

To control underwater construction work, as well as subsequent minor repairs of underwater mechanisms during the operation of the dam, an automatic diving device was designed - a robot called Portunus ("Crab"), equipped with a television camera and mechanical manipulators.

So, the Osterschelde protective shield went into operation. It is assumed that the need to completely block the culverts of the dam may occur 1–2 times a year when the sea tide coincides with the extreme wind surge. In addition, control and repair lowering of the gates will be carried out once a month.

The entire operating staff of this unprecedented hydrotechnical system in the world consists of 50 employees, who are located in the management building on the island of Neeltje Jans. It also houses a museum that tells about the Delta project and the history of its implementation.

The history of the relationship of the inhabitants of the Netherlands with the North Sea is a characteristic way of interaction between civilization and the environment. Starting with blind admiration for the elemental forces of nature, fear of their destructive raids, man gradually moved first to passive defense and defense of his positions, and then to a decisive offensive.

He conquered nature, conquered new footholds, but suddenly stopped and thought ... Is he likened to the Epirus king Pyrrhus, who won in bloody battles, but was left almost without an army.

Since that time (in which we live) a period of doubt and reflection began. Will man continue to carry out his broad plans for the transformation of nature, or will he abandon them and become more concerned with her protection and protection?

From the book of Stratagems. About the Chinese art of living and surviving. TT. 12 author von Senger Harro

29.5. Playing cards at three degrees below zero During the visit of US President Richard Nixon to China on February 21-28, 1972, "Potemkin villages" were organized several times. When Nixon and his companions visited the Great Wall of China, local authorities rounded up

From the book Black Legend. Friends and Enemies of the Great Steppe author Gumilyov Lev Nikolaevich

Two orders of magnitude lower. All the above cases of passionary explosions, although they explain the change of ethnic groups, leave, when presenting the material, a shadow of doubt: “Maybe this is an explosion of ethnogenesis, a push - can it be explained in some other way? Of course, the preaching of Muhammad in Medina and

From the book Day of Shame. Second Pearl Harbor by Lord Walter

AFTERWORD, which may well be considered a preface to the material published below. Many well-documented events in our history, including the history of modern times, have no rationally explainable reasons. This is recognized today by serious

From the book Black Legend author Gumilyov Lev Nikolaevich

author Team of authors

2. Increasing the level of income of the working people The first five-year period was marked by a huge increase in the number of workers and employees employed in the national economy. If in 1913 12.9 million workers and employees were employed in the national economy (within the borders of the USSR until September 17, 1939) and by the beginning

From the book Creating the Foundation of a Socialist Economy in the USSR (1926-1932) author Team of authors

3. Raising the Level and Improving the Structure of Consumption Direct evidence of the improvement in the material situation of the broadest strata of urban and rural workers during the years of the first five-year plan is provided by data on the growth in the production of industrial consumer goods per capita:

From the book Stalin is the undertaker of the Red Army. The main culprit of the Catastrophe of 1941 author Beshanov Vladimir Vasilievich

"Flying coffins" of Stalin. "Down, and down, and down..."

From the book Jews and Life. How the Jews descended from the Slavs author Dorfman Michael

That among the Jews below the belt Judaization was subjected not only to religious and theological concepts, but also to everyday, decent and not very. The process called Judaization is not something exclusive to the Hebrew language. Similar processes are going on all the time.

From the book World History: in 6 volumes. Volume 3: The World in Early Modern Times author Team of authors

FROM SEA TO SEA: THE FLOOD AND OTHER WARS While the protracted Franco-Spanish War was coming to an end in the West of Europe, the East of the continent from the Baltic to the Black Sea became the scene of a multilateral international conflict in which, in addition to the main protagonists (Russia,

From the book The Little Book of Capoeira author Capoeira Nestor

The Three Levels of the Game Dividing by three has long been a common way of analyzing the whole: the Freudians talk about the ego, the superego and the individual. Hindus talk about Brahma, Vishnu and Shiva. Christians talk about the Father, the Son and the Holy Spirit. Let's share for didactic purposes

From the book How Zyuganov did not become president author Moroz Oleg Pavlovich

I. Lower and lower and lower... How Yeltsin's rating was falling So, by the end of 1995 - the beginning of 1996, Yeltsin approached with almost zero rating. This despite the fact that at the start of the first presidential term, his popularity was very high. For the first time, Yeltsin became politician No. 1 in 1990. AT

From the book Anti-Semitism as a Law of Nature author Brushtein Mikhail

From the book Stalin's Last Fortress. Military secrets of North Korea author Chuprin Konstantin Vladimirovich

Joseon from sea to sea: geography and population North Korea (in Korean, Korea - "Joseon", which translates as "Land of the Morning Calm") is officially called the Democratic People's Republic of Korea (DPRK, "Joseon Minjujuyi Inmin Gongwa Guk"). By

From the book Religious Wars author Live Georges

2. Rising prices and falling living standards. Not knowing the true reasons for the rise in prices, the majority of contemporaries are content with stating this rise. They expose the excessive high cost of essential necessities and the increase in taxes caused by it, the decrease in the number of

From the book Court of Russian Emperors in its past and present author Volkov Nikolai Egorovich

XXXIII. On the non-promotion to the rank of chamberlain of officials below the titular councillor, and to the chamberlains below the state councilor

From the book History of the Ukrainian SSR in ten volumes. Volume Nine author Team of authors

CHAPTER V IMPROVING THE LIVING STANDARDS OF THE WORKING PEOPLE OF THE REPUBLIC The war significantly worsened the material situation of the Soviet people. At the site of the battles, on the territory subjected to temporary occupation by the Nazis, ruins and conflagrations, destroyed residential buildings, schools,

If you have ever climbed the tops of mountains, then you know the feeling when even with a deep breath there is not enough oxygen. But there are people in the world who live, work, and rest in such conditions. They have been able to adapt to a wide variety of environmental conditions, including towering mountains that rise more than two miles above sea level.

The highest cities in the world - La Rinconada, Peru

The highest city in the world is located in the Andes near the border with Bolivia, at an altitude of more than 5100 meters above sea level. The population of the town is 30 thousand people. According to doctors, such a height is the limit for the human body.

The city was founded on a mine, where most of the inhabitants work. Despite the very harsh climate: during the day the temperature rises several degrees above zero, at night it is cold, people are in no hurry to leave their homes in search of better living conditions. Even the lack of oxygen did not stop the population growth. In the 21st century, it has increased by 231%.

And all because of the rich reserves of gold ore. Residents work in difficult conditions. Some of them even work for free for a whole month, so that on their last day they can take as much ores as they can carry on their own. The city can only be reached by one narrow mountain road.

The highest cities in the world - Namche Bazaar, Nepal

A favorite place for tourists and climbers from all over the world, because it is located on the road to Everest, and its height is 4150 meters above sea level. The town serves as the main transit point for people who are going to climb further to the camp on the mountain. This is the last refuge of civilization before the highest mountain in the world.

The city was originally built as a trading zone, where shepherds who raised herds of yaks high in the mountains could exchange the butter and cheese made from the milk of these animals for agricultural products grown in the lower regions of Nepal. Namche Bazaar is still the main commercial center of the Khumbu region.

There is electricity in the town, there is an airport nearby (more precisely, a heliport), but most tourists cannot use it because of the protests of local residents. For mass tourism, the Lukla airport is used, from which tourists must make a daily transition to Namche Bazaar (in the case of a very fast walk, six hours is enough). Serving tourists at this site provides employment and income for local residents.

Namche Bazaar also houses official offices, police control, a post office and a bank. At the top are the barracks of the Nepalese army. There are hotels on the territory of the city, which are equipped with special rooms that help people adapt to the rarefied mountain air.

The highest cities in the world - El Alto, Bolivia

Despite being located at 4150 meters above sea level, the city of El Alto ranks second in terms of the number of inhabitants in Bolivia - 1 million 700 thousand people.

This town was founded during the construction of the railway connecting La Paz and Lake Titicaca. El Alto is one of the fastest growing cities in the world. In 1992, 424 thousand people lived here, in 2001 - 647 thousand people, in 2010 - already 992 thousand, in 2011 the number of citizens of El Alto exceeded 1 million.

The region around El Alto is home to numerous industries; it is also home to one of the highest airports in the world - La Paz.

The highest mountain cities in the world - Potosi, Bolivia

Another mountainous city in Bolivia is located at an altitude of 4,090 meters above sea level. This city at one time was built as a mining settlement and was the most popular and richest city in the world. And all because silver was mined here. As of today, silver reserves have dried up, but this industry is still functioning.

The highest mountain cities in the world - Juliaca, Peru

This city is interesting not only for its location, but also for its name. It can be included in the rating of cities with funny names. The city is located at an altitude of 3,825 meters above sea level in the Puno region, 45 kilometers from the famous Lake Titicaca. The city is also an important transportation hub for the region.

Any tourist traveling to new countries will wonder how cities exist below sea level, and why it is not necessary to take rubber boots with you to stay with dry feet.

Low sections or the so-called depressions are formed at the boundaries of tectonic plates. The formation of depressions occurs when the plates converge or diverge. Most of these sites are located in the northern hemisphere. But heat and evaporation just prevent the filling of depressions with water.

The first country that many people remember is Netherlands. Arriving at Schiphol Airport, located 4.5 meters below sea level, it becomes terribly interesting how the Dutch manage to keep such a restless sea. The lowest dry point in Europe is the city Rotterdam located 7 meters below sea level. Next comes Nieuwe Kerk, 6.74 meters below sea level, followed by Amsterdam, built on stilts. Still don't know

If you go to the USA in the state of Louisiana, you should definitely visit New Orleans located 4 meters below sea level. Many people remember the year 2005 and the invasion of Hurricane Katrina, which claimed the lives of thousands of people, left families homeless, and destroyed everything in its path.

Going to Israel and visiting Dead Sea, do not forget that it is located 422 meters below sea level. It's hard to believe, but it's true. But since we have already started talking about cities, we will immediately recall a small settlement in southern Israel called Neve Zohar. There are few tourists passing through here, with the exception of those who travel here purposefully, there are not many luxury hotels, but it is here that you can find a lot of historical treasures, for example, Roman-Byzantine fortifications, ruins from the time of the Jewish kings, as well as caves where burials are located Byzantine period. Not everyone knows that Neve Zohar is one of the lowest settlements, located even lower than the shores of the Dead Sea. Indigenous people are represented by 30 families.

But in the Republic of Djibouti (East Africa) there are lake Assal located a 155 below sea level. The concentration of salt in the water reaches 34.8%, which is even more than in the Dead Sea. The main industry here, of course, is the extraction of salt, which is transported to Sudan.

The lowest city is Jericho located on the territory of the partially recognized state of Palestine. This is one of the oldest cities mentioned in the Bible. The city is known not only as the oldest with the first traces of people here, but also the lowest, located at an altitude of -275 meters. You can go on an excursion to Jericho together with a group of tourists, while it is desirable that the guide coordinate everything with the Ministry of Tourism, because, as you know, the situation in Palestine on the border with Israel is unstable. In case you don't know where to stay, we are at your service.

And now let's go to Absheron Peninsula, where the height of the plain is -26 meters below sea level. Oil and gas production takes place here, and besides, this place is unique for its historical monuments, for example, the Nardaran fortress built in the 14th century, the round castle of the 11th century and the temple of fire, which was built in the 17th-18th centuries. And Baku itself, the capital of the Republic of Azerbaijan, is located two meters below the plain and, without exaggeration, there is something to do not only for a tourist, but also for a traveler who wants to spend a few days here.

Going on a trip and want to book accommodation at a discount?