New York's Manhattan Grid - a blueprint for the US' biggest city

Aerial view in 21st century of the Manhattan Grid started in 1811

Before it could rise into the sky, Manhattan had to first create the streets, avenues and blocks that would later support the 20th century skyscrapers. In the early 19th century, New York's population was continuing to increase having tripled to 96,373 since 1790 mostly due to the growing port. It was then predicted that 400,000 people would live in the city by 1860. The City planners were entrusted with planning the city in 1811. They proposed a grid for the future city stretching northward from roughly Houston Street to 155th Street in the faraway heights of Harlem as the layout in the photo (above) and map (below) show.

Manhattan Grid Plan

 

The Grid Plan

The grid plan is a type of city plan in which streets run at right angles to each other to form a grid. The Greeks and Romans used City Grids as did the Chinese from 1500 BC onwards. The Chinese Tang 唐 Dynasty laid out their capital city in a grid plan.

The Roman model was also used in Spanish settlements during the exploration of the Americas. In 1573, Felipe II compiled the Laws of the Indies to guide the construction and administration of cities in the Americas. The Laws specified a square or rectangular central plaza with eight principal streets running from the plaza's corners. The grid plan became popular with the start of the Renaissance in Northern Europe. In 1606, the newly founded city of Mannheim in Germany was the first Renaissance city laid out in the grid plan as the map below shows. 

Mannheim Grid Plan

 

Why use grids?

An inherent advantage of the geometry of a proper grid is its tendency to provide regular building space in well-spaced sequences. This maximises the use of the land of a block without affecting street frequency - any frequency of streets produces the same packing effect. Furthermore geometry also minimises disputes over lot boundaries and maximises the number of lots that can front a given street.

Another important aspect of street grids is that traffic flows of either pedestrians, cars, or both, only cross at right angles. This is an important safety feature, since no one entering the intersection needs to look over their shoulder to see oncoming traffic. Hence the grid is a geometric response to our human physiology. It is highly likely that the original purpose of grid layouts comes from the Athenian Agora where the laying out of market stalls into regularised rows at right angles solved the problem of frequent wagon collisions that occurred when the markets were laid out randomly in a field with traffic approaches at odd angles.

New York's Manhattan Grid

The Manhattan grid plan was a far-reaching, visionary and daring plan to urbanize the geographical limits of the Island of Manhattan.The plan called for a regular grid of streets and property lines without regard to the topography of the island itself. This included numbered avenues running north and south roughly parallel to the shore of the Hudson River. The avenues would begin with First Avenue on the east side and run through Twelfth Avenue in the west. There would also be 155 orthogonal cross streets. 

Interestingly, Manhattan’s grid is not perfectly regular. No two blocks are ever precisely the same because the grid indulges variety, building to building, street to street. Some avenues are wider. Broadway cuts diagonally across the north-south streets, and those cuts have made room for public spaces (Union Square, Madison Square, Herald Square, Times Square, Columbus Circle, Verdi Square). 

New York’s grid has proved flexible enough to adapt when the city’s orientation has shifted north-south, and flexible enough to accommodate the creation of Central Park which interestingly was not a part of the original grid plan. It was not until 1853 that the idea for a large area of green space for leisure activities was envisioned.
 

One of the advantages of the Manhattan city grid is that it makes a complex place instantly navigable. Manhattan invites long walks, because walkers can judge distances easily and always know where they are. In contrast other cities such as London which are formed from historic agglomerations of villages, often include vast stretches of nowhere land as they sprawl in ways that discourage easy comprehension and walking. 

 

Finally, perhaps one of the greatest benefits of the Manhattan grid is that it gives order through physical form to a city filled with a diversity of ideas, concepts and people from so many different places. It is not likely that this is exactly what the original city planners had in mind back when they proposed that the Manhattan Grid should "promote the health of the City" back in 1811.  

Water for the North of China – 南水北调



Map of the three routes for the South-to-North Water Transfer Project to
alleviate the lack of water in the north of China


Water scarcity in Chinese history is a big issue. China has suffered from water scarcity in the north since ancient times. Summer monsoon winds originating in the Indian Ocean sweep into China. When the summer monsoon is stronger, the moisture-laden winds push the rains farther northwest into China. But when the monsoon is weak, the rains fall farther south and east, depriving northern and western parts of China of summer rains.

Recent research on the strength of monsoon rains over the last two millenia has thrown up some interesting results. The research was based on the layers of stone in a 118-mm-long stalagmite dating from 190 AD found in a cave in Gansu Province in China. It has allowed researchers to match, the amounts of uranium and thorium throughout the stalagmite, to tell the date each layer was formed with the “oxygen signature” in the stalagmite that shows the amounts of rainfall—a measure of summer monsoon strength—to those dates. The researchers discovered that periods of weak summer monsoons coincided with the final years of the Tang (618-906AD), Yuan (1279-1368AD) and Ming (1368-1644AD) dynasties, which are known to have been times of popular unrest and social upheaval. In contrast, strong summer monsoons prevailed during one of China's "golden ages," the Northern Song Dynasty (960-1279AD).

Without the strong rains, food becomes scarce causing social problems and unrest. Hence it is no coincidence that China's most successful dynasties all fell in times of water scarcity. In the 20th century Mao was greatly aware of the need to keep the north watered, in 1952, he called for a scheme that would divert water from the southern Chinese rivers to the north to ease the growing water shortages in the cities of Beijing and Tianjin and the northern provinces of Hebei, Henan and Shandong.

The South-to-North Water Transfer Project

In the 21st century, the mammoth task of transferring water to the north has begun. The South-to-North Water Transfer Project is an incredible feat of engineering on a very grand scale, the aim of the project is to transfer at least 44.8bn cubic metres of water each year from the the Yangtze River in the south, to counter the thirst of the north China plain and its 440 million people. It is the largest project of its kind ever undertaken in the world. The rapid growth of megacities — around 22 million people in Beijing and 12 million in Tianjin alone — has put considerable strain on the ground water aquifiers in the north. In recent years, urban and industrial development has often been supplied with water at the expense of agriculture leading to severe water shortages in rural areas.

Map of the the three routes of South-to-North Water Diversion Project

The project will link China's four main rivers – the Yangtze, Yellow River, Huaihe and Haihe – and requires the construction of three transfer routes, stretching south-to-north across the eastern, central and western parts of the country. In August 2002, the project was approved  and work began on the eastern route of the project in late 2002, and on the central route in 2003. The Central route is due to be completed shortly. Work on the western route is more complicated and is not due to be completed until 2050.

But not everyone is in favour

The project has been criticised for its lack of concern for the environmental impact and the human impact on people being relocated to make way for the canal on the central route. Questions about the cleanliness of some of the water being transferred have also been raised. In the US, the New York Times said the project was like "...channeling water from the Mississippi River to meet the drinking needs of Boston, New York and Washington." 

The below video report provides some further opinions on the the South-to-North Water Transfer Project:

Nevertheless, it is clear, that if China is to continue its growth and development in the 21st century, it must resolve the problem of water scarcity in the north. With 22pc of the world's population, China has only 8pc of the world's fresh water which adds to the challenge. Its per capita availability of fresh water is barely a quarter of the world average. Furthermore, the north accounts for around 37pc of the country's total population, but has only 12pc of the country's total water resources. Yet, in the south, about 1,000bn cubic meters of water from the Yangtze River empties into the sea each year. There is no easy solution to this geographical conundrum and the scale of the problem is huge.

The Geo-Trade Blog believes the South-to-North Water Transfer Project provides a practical solution to a tricky geographical problem that goes back thousands of years. The water transfer project appears to be a logical trade-off as long as the north continues to play fair and does not take advantage of the arrangement to develop further at the south's expense by taking a greater share of the water from the Yangtze River. Although if water remains at present levels, there appears to be enough water for all.

Cities in the 21st century — a city-dominated world

Picture of Beijing in the 21st century

The 18th and 19th centuries were the last centuries of empire in the world. The idea of the nation-state took hold in the 19th century. The Wesphalian idea of nation-state sovereignty that basically says that a nation's affairs are its own, and no other state has the right to act within its borders has been the basic diplomatic template since the 17th century. The limits to the nation-state were shown by European rivalries at the beginning of the 20th century while growth in cities began to flourish from the mid-20th century across the world. As a consequence the 21st century looks set to become the 'century of the cities'.

By the year 2030, three out of five people will live in cities. The UN forecasts that today's urban population of 3.2 billion will rise to nearly 5 billion by then. The top 25 cities in the world account for more than half of the world's wealth. And the five largest cities in China and India account for 50pc of those countries' wealth.

This increase will be most dramatic on the least-urbanised continents, Asia, América Latina and Africa. Surveys and projections indicate that most urban growth in coming years will be in emerging economies as the map below indicates.


Map of Growth in Cities since 1950s, 2000s and projected to 2015

Mega-regions

A new concept has recently arisen in the growth of cities known as the 'mega-region'. A mega-region occurs when growth in cities in a particular region is accelerated. Research shows that the world's largest 40 mega-regions cover only a tiny fraction of the habitable surface of the planet and are home to fewer than 18pc of the world's population but account for 66pc of all economic activity and about 85pc of technological and scientific innovation. The mega-regions, rather than countries, are becoming the key driver behind economic development and wealth creation.

The largest of these is the Shenhzen-Guangzhou region in China, home to about 120 million people. China is planning to create the world's biggest 'mega-region' by merging nine cities to create a metropolis twice the size of Wales with a population of 42 million.

Map of new Chinese mega-region

The new mega-region will cover a large part of China's manufacturing heartland, stretching from Guangzhou to Shenzhen and including Foshan, Dongguan, Zhongshan, Zhuhai, Jiangmen, Huizhou and Zhaoqing. Together, they account for nearly a tenth of the Chinese economy.

By 2015, around 150 major infrastructure projects will mesh the transport, energy, water and telecommunications networks of the nine cities together, at a cost of some 2 trillion yuan (£190 billion). An express rail line will also connect the hub with nearby Hong Kong.

A new concept 'Aerotropolis'

In a new book titled “Aerotropolis: The Way We’ll Live Next” by Kasarda and Lindsay, the authors develop a vision of the 'aerotropolis' as a symbol of a city-dominated world. The aerotropolis is “glocal,” a place that draws on local competitive advantages (like cheap labor) as it plugs into the  21^st century global on-demand-production supply chains. Therefore it makes sense to affix cities to airports on the model of the aerotropoli for air transport companies such as Fedex and UPS. Hence an airport, having begun life as an outlying curiosity, on the edge of the city, becomes the heart of the mega-region or mega-city, its raison d’être.

The book illustrates this new concept through a series of compelling numbers. While world GDP rose 154pc between 1975 and 2005, world trade grew 355pc. Meanwhile, the value of air cargo climbed an astonishing 1,395pc. More than a third of all the goods traded in the world, some $3 trillion worth - but barely one percent of its weight! - travels via air freight.

If the book is right and Aerotropoli do take off, then, this has the potential to further push international trade relations between mega cities and mega-regions into the foreframe and leave the country relationship as a minor detail. For example, when New Songdo, an aerotropolis near Seoul, does business with São Paulo, the South Korean-Brazilian relationship is of little interest. Likewise the new Chinese Shenhzen-Guangzhou mega-region is likely to pay little attention to what the UK thinks, but will be very interested in London.