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City Transformation due to Ecological Imbalances


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City Transformation due to Ecological Imbalances

  1. 1. II Semester M.ARCH. (URBAN REGENERATION) JMI Ecological Transformations
  2. 2. Populations on the Rise! • Cities have existed for thousands of years and can be traced back to the river valley civilizations of Mesopotamia (present-day Iraq), Egypt, India, and China. At first, these settlements depended largely on agriculture and domestic cattle, but as they grew in size they became centers for merchants and traders. • Urban growth, also known as urbanization, accelerated dramatically with the advent of industrialization some 200 years ago. At that time, large numbers of people moved to cities in search of jobs, mostly in factories. But the most rapid growth has taken place over the past 50 years. While less than one-third of the world's population lived in cities in 1950, about two thirds of humanity is expected to live in urban areas by 2030. Most of that urbanization is taking place in Asia, Africa, and Latin America.
  3. 3. Populations on the Rise! • Urban is defined as "that which is characteristic of a city." But what exactly is a city? In the past, walls may have defined a city. But today's city boundaries are often blurred. Are suburbs, which are often called metropolitan areas, part of cities? Depending on the boundaries used, Tokyo can have a population of anywhere between 8 and 40 million people. • Cities make a lot of sense for humans. People are concentrated in a small space rather than being spread out over a large territory. This allows the government and others to provide more service such as water, electricity, and transportation to a larger number of people. Schools and shops are more easily accessible than in rural areas.
  4. 4. Populations on the Rise! • Cities have always been at the center of economic growth and technological advances. The promise of jobs and prosperity pulls people to cities. But their rapid growth has also brought with it many negative things: violence, poverty, overcrowding, health problems, and pollution. Many cities in developing countries in particular are growing too rapidly for their own good, with many residents unable to find jobs and forced to live in slums. • Urban expansion is also encroaching on wildlife habitats everywhere. Increasingly people live and work in close proximity to wild animals whose native habitats have been lost or broken up. Many animals—from mice and cockroaches to pigeons and squirrels—have adapted to city life, taking advantage of abundant food and warmer temperatures.
  5. 5. Environment and Society Ecology is the study of the interaction of living organisms and the natural environment. Humans have transformed half of the world’s land surface and use more than half of all the accessible surface fresh water in the world.
  6. 6. Ecological Issues The world is now facing an environmental deficit, profound and negative harm to the natural environment caused by humanity's focus on short-term material affluence. This concept implies three important ideas: • The state of the environment is a social issue. • Environmental damage is often unintended. • Much environmental harm is reversible. By: Alan S. Berger, 2010
  7. 7. Ecological Issues • Culture: Growth and limits – The logic of growth thesis is a widely accepted cultural value which suggests that growth is inherently good and that we can solve any problems that might arise as a result of unrestrained expansion. – The limits to growth thesis holds that humanity must implement policies to control the growth of population, material production, and the use of resources in order to avoid environmental collapse.
  8. 8. Population on Rise! Cities and Suburbs Urban areas are cultural and technological epicenters ranging from quaint municipalities to sprawling megacities. They have existed for millennia. But over the last half century, their size and influence has been expanding rapidly, particularly in emerging nations like China and India.
  9. 9. A Northern Virginia housing development encroaches on farmland. Population growth and relocation is threatening rural environments across the world.
  10. 10. Ecological Issues
  11. 11. Ecological Issues • Solid waste: The disposable society. – Why Grandmother Had No Trash. – Landfills pose several threats to the natural environment. – Recycling, reusing resources discard, is one solution. we would otherwise
  12. 12. Ecological Issues
  13. 13. Ecological Issues • Air – A deterioration of air quality was one of the unanticipated consequences of the development of industrial technology.
  14. 14. Ecological Issues • Air – A deterioration of air quality was one of the unanticipated consequences of the development of industrial technology. Pollution contributors: example of Delhi
  15. 15. Ecological Issues • Rain forests are regions of dense forestation, most of which circle the globe close to the equator. • Global warming is apparently occurring as a result of the greenhouse effect, a rise in the earth’s average temperature due to increasing concentration of carbon dioxide in the atmosphere resulting in part from the decline of the rain forests. – The shrinking of the rain forests reduces the earth’s biodiversity.
  16. 16. Ecological Issues • Water supply is problematic in many parts of the world. • A special problem is acid rain, rain that is made acidic by air pollution and destroys plant and animal life. • Water Consumption in Global Perspective. Some countries do not have an adequate supply of water. • Polluted water is an increasingly serious concern as well.
  17. 17. Ecological Issues Sources of Water; • Ground water • Pond • Lake • River • Sea • Air (moist air flowing from sea to desserts is used to extract water from air. A usual practice in UAE)
  18. 18. River for Drinking Water
  19. 19. River for Domestic use
  20. 20. River for Food
  21. 21. River for Food
  22. 22. River for Agriculture
  23. 23. River for Shelter
  24. 24. River for Shelter
  25. 25. River for Transportation
  26. 26. River for Retreat/Tourism
  27. 27. River for Energy
  28. 28. River for Energy
  29. 29. River as Faith
  30. 30. RIVERS • Lifeblood of many plant, animal, and human communities. • Yet many of the world's rivers have been – dammed, – degraded, – polluted, and – overdrawn at alarming rates.
  31. 31. Rivers don't always reach their ends… • Many rivers dry out or else die out before reaching sea because people have divert water so much for agriculture, industry, and municipal uses. • Other rivers have been completely covered over by development, as people attempted to "tame" nature by ending flooding and maximizing usable land area.
  32. 32. Fresh water ecosystems? Ques.) But what happens to once-thriving freshwater ecosystems when the rivers they depend on are entombed in sewer pipes beneath layers of concrete and soil? Ans.) Few species can make the transition to subterranean living. Ironically, it was often rivers and streams that attracted people in the first place, but those very sources of life can fall victim to the expanding concrete jungle.
  33. 33. River: Sunswick Creek Location: Queens, New York City maps of 1870s
  34. 34. Sunswick Creek ran through Queens until the late 19th century, originat ing in the south of the Ravenswood area. These maps below are from 1873.
  35. 35. Photograph by Steve Duncan The waterway was above ground at least through the 1870s. Eventually, however, it was completely covered over, though it's apparent inside the thing that different parts of the tunnel were covered over at different times.
  36. 36. Photograph by Steve Duncan Now, it exists only as a meager flow through buried sewer-like pipes.
  37. 37. Photograph by Steve Duncan Duncan notes that the burial process appears to have occurred in multiple phases, based on his explorations of the dank channels.
  38. 38. Tibbetts Brook, New York City • • • • • Tibbetts Brook starts just north of the Bronx and then flows into the borough's leafy Van Cortlandt Park, where it fills a small lake. Thanks to historic development, the brook is then forced underground at Tibbett Avenue. It then flows under the Bronx through a large, double-channeled brick sewer until it reaches the Harlem River Ship Canal, which was dug in the 1890s, shaping the border with Manhattan. Before development, the Lenape Native Americans who lived in the area took advantage of the brook's freshwater and plentiful fish and game, which included muskrats, raccoons, rabbits, skunks, and many species of birds. The Lenape called the stream Mosholu, meaning "smooth or small stones." In the 1690s, property owner Jacobus Van Cortlandt built the small dam that created the lake, in order to power a sawmill and gristmill. He also cut ice from the lake in winter to sell to locals. The city of New York acquired the land that became Van Cortlandt Park in 1888. Today only a small part of Tibbetts Brook remains above ground. Runoff of toxins from the surrounding city remains a problem for water quality. In 1961, pollution seeped into the stream, leading to the death of thousands of fish in the lake.
  39. 39. Photograph by Steve Duncan
  40. 40. Sawmill River, Yonkers, New York • The longest tributary of the mighty Hudson River, the Sawmill River flows about 23 miles (37 kilometers) from Chappaqua, New York, to Yonkers, just north of New York City. Since the early 1900s, the last 2,000 feet (600 meters) of the river have been entombed in a flume underneath downtown Yonkers. • The river was covered gradually. First, bridges were built across it. Over time, the bridges got bigger and closer together, as Yonkers experienced rapid industrialization. Eventually, the river was completely covered over, and it has historically suffered from pollution and intense development. • In 2007, a $34 million plan was approved to expose, or "daylight" much of the buried section of the Sawmill River, as part of a $3 billion redevelopment project for Yonkers. This will include a new city park. • Scientists hope that exposing the river to daylight will help restore it to a better state of health. A BioBlitz was conducted in 2009 to assess the health of the watershed. Participants counted eight species of fish, though more than 20 were counted by scientists in the past. Native Americans called the
  41. 41. Photograph by Steve Duncan
  42. 42. Park River, Hartford, Connecticut • In the 1940s, the U.S. Army Corps of Engineers diverted the Park River beneath Hartford, Connecticut, in what was one of the largest and most expensive projects the Corps had tackled up to that point. The Park had connected the city's west side to the larger Connecticut River, though it had long been abused as a dumping ground for sewage and industrial waste. • Long called Hog River because of its stench, the Park was buried 30 to 50 feet below the surface, where it still runs under the state capitol and main public library. • Today, a few intrepid urban explorers paddle canoes down the buried river. John Kulick of Huck Finn Adventures, who has guided float trips through the subterranean section, told the New York Times he has seen eels, carp, and stripers in the dark water. Kulick joked, perhaps at least half seriously, that a burst of water gurgled into the river because "someone flushed a toilet."
  43. 43. Photograph by Steve Duncan
  44. 44. Neglinnaya River, Moscow • The Neglinnaya River (also called the Neglinka River) used to flow across Moscow from north to south, until it was buried underground in 4.7 miles (7.5 kilometers) of tunnels. Today it drains into the Moskva River via two openings. • The Kremlin was built on a hill west of the Neglinnaya River, with a moat filled from its channel. Over time residents grew weary of the river's flooding, so in 1792, the city diverted its course into a new canal, and filled in the original bed. After a devastating fire in 1812, the river became heavily polluted, so engineers covered it over with a vault. • In subsequent decades, additional tunnels were built or expanded
  45. 45. Photograph by Steve Duncan
  46. 46. Wein River, Vienna • The Wein River was driven below Vienna long ago, where it was integrated into the city's sewer system. Fans of classic movies may recognize this tunnel from the 1949 Orson Welles film The Third Man, set in postwar Vienna. Photograph by Steve Duncan
  47. 47. Bradford Beck River, Bradford, England • Beautiful arched foundations can be seen along the underground Bradford Beck River in Bradford, England. Urban explorer and photographer Steve Duncan believes this section underlies Bradford City Hall, a Victorian-era structure built in the 1880s. (Duncan has traveled the world in search of subterranean rivers.) • According to Duncan, the Bradford Beck flows about four miles through a wide variety of tunnel architecture and building foundations. Photograph by Steve Duncan
  48. 48. River Sheaf, Sheffield, England • This large area is the end of the tunnel that contains the River Sheaf as it travels through the city of Sheffield. The river emerges from time to time as it passes beneath the city, before it merges with the River Don near Blonk Street Bridge. • The River Sheaf historically suffered severe pollution from industrial activities in the area, especially metalworks, although recent efforts have been made to improve water quality. Photograph by Steve Duncan
  49. 49. River Westbourne, Lo ndon • A number of watercourses through London were buried over the centuries, including the River Westbourne, which flowed from Hampstead through Hyde Park to Sloane Square and into the River Thames at Chelsea. Photograph by Steve Duncan
  50. 50. River Westbourne, London • The River Westbourne had been an important source of drinking water for the growing city, and conduits were built for that purpose in 1437 and 1439. However, by the 19th century, the water had become too filthy to use for anything except a sewer. Photograph by Steve Duncan
  51. 51. River Westbourne, Lo ndon • In the early part of the 19th century, the River Westbourne was channeled into underground pipes to make more room for the growing areas of Chelsea, Paddington, and Belgravia. That work was completed in the 1850s, and the river has remained "lost" ever since. Photograph by Steve Duncan
  52. 52. River Westbourne, Lo ndon • Part of the original iron pipe can still be seen running above the Sloane Square tube station, where it survived intense bombing by Germany in World War II. Photograph by Steve Duncan
  53. 53. River Fleet, London • The largest of London's lost rivers, the River Fleet flows four miles (6.4 kilometers) underground through downtown before it enters into the Thames. Here, it splits into two 12-foot-high (3.7-meter-high) brick tunnels not far from St. Paul's Cathedral. • The Fleet was forced underground and combined with the sewer system in the 19th century. In Roman times, it had been a major and important river. By the 13th century, the Fleet had already become polluted, since it was long used as a sewer. Much of its water was also gradually diverted for industry. • After the Great Fire of London in 1666, the river was reshaped into a canal. Over time this was increasingly covered over by development, until the process completed around 1870. • Today the River Fleet can still be heard gurgling below a grating at Ray Street. The river's name lives on as the inspiration for Fleet Street.
  54. 54. Photograph by Steve Duncan
  55. 55. River Walbrook, London • The Roman settlement of Londinium, the precursor to today's city, was bisected by a river called the Walbrook, perhaps named because it flowed under the fortified walls. The stream started in what is now Finsbury and flowed into the River Thames near today's Cannon Street Railway Bridge. • The river was long used as a sewer, as well as for drinking water, and its quality began to decline as early as the Roman period. By 1598, historian John Stow wrote that the Walbrook was being paved over with bricks to make way for housing. • By the 1830s, what remained of the Walbrook's flow was coursing through city sewer lines, where it remains today. According to Steve Duncan, groundwater in the area works its way through the brick of the tunnel, spraying from every direction.
  56. 56. Photograph by Steve Duncan
  57. 57. Colorado River • The Colorado River is one of the most used and contested waterways on Earth. It provides water for 30 million people, and has many dams and diversions along its 1,450 miles (2,333 kilometers). • Because it is so heavily tapped for agriculture, industry, and municipal uses along its course, the Colorado River rarely reaches its delta and the Gulf of California. About one-tenth of the river's former flow now makes it to Mexico, but most of that is used for farming and cities south of the border. Photograph by Peter McBride For National Geographic
  58. 58. • Balancing Limited Supply With Increasing Demand • The Colorado River Basin is a critical component of North American water supply, providing H2O to 30 million people and thousands of acres of farmland. When Colorado River withdrawals were first allocated among the river basin’s seven states, in 1922, the river held 17.5 million acre-feet (5.7 trillion gallons) of water. However, new science has shown that 1922 was part of an especially wet period. The river now averages about 14.7 million acre-feet per year and is allocated among seven states and Mexico. Water managers are trying to address growing challenges associated with over-allocation, rapidly increasing urban populations, development of unused water rights, and expected climate change. The water levels of the river’s two largest reservoirs—Lake Mead and Lake Powell, stored by Hoover and Glen Canyon Dams—have dropped significantly in recent years, threatening supplies for major cities. In addition, the trapping of silt behind dams also limits the quality and extent of river habitats.
  59. 59. Colorado River • A growing coalition of advocates is working to restore some of the water in the Colorado, with hopes of regenerating the now-arid delta (previous image) and important ecosystems along the way. • More people have come to appreciate the vital role the river plays on both sides of the border. There is growing interest in removing some of the dams along its path, including the controversial Glen Canyon Dam near the Grand Canyon. Photograph by Peter McBride For National Geographic
  60. 60. Amu Darya River • • • • • Aral Sea, once the world's fourth largest inland water body with a surface of 26,000 square miles (67,300 square kilometers). The sea was once ringed with prosperous towns and supported a lucrative muskrat pelt industry and thriving fishery, providing 40,000 jobs and supplying the Soviet Union with a sixth of its fish catch. The Aral Sea was originally fed by two of Central Asia's greatest rivers, the Amu Darya in the south and the Syr Darya in the north. The former is the longest river in the region, snaking through 1,500 miles (2,414 kilometers) of steppe. But in the 1960s, the Soviets decided to make the steppes bloom. So they built an enormous irrigation network, including 20,000 miles of canals, 45 dams, and more than 80 reservoirs, all to irrigate sprawling fields of cotton and wheat in Kazakhstan and Uzbekistan. The system was leaky and inefficient, however, and after several decades, the Amu Darya had lost so much of its flow that it no longer reached the Aral Sea. Today, it ends about 70 miles (110 kilometers) away. Pictured is the Amu Darya a little ways upstream from where it dries out. Deprived of a major source of its water, the inland sea shrank rapidly. In just a few decades, the Aral Sea was reduced to a handful of small lakes, with a combined volume one-tenth the original and much higher salinity due to all the evaporation. Millions of fish died, coastlines receded miles from towns, and those few people who remained were plagued with toxic dust storms, the residue of industrial agriculture and weapons testing in the area. Photograph by Matthieu Paley, Corb For National Geographic
  61. 61. Syr Darya River • Although the Syr Darya fared somewhat better than its sister river, the Amu Darya, it was also heavily tapped and polluted. The Syr Darya starts in the Tian Shan Mountains of Kyrgyzstan and Uzbekistan and flows 1,374 miles (2,212 kilometers) toward what's left of the Aral Sea. (Pictured is a reach near Tashkent) • In the 18th century, a system of canals was built on the river. These structures were greatly expanded by Soviet engineers during the 20th century, largely to grow vast quantities of cotton. Virtually the entire flow was diverted, leaving only a trickle into the inland sea. • The deputy director of Kazakhstan's agency for applied ecology, Malik Burlibaev, recently warned that "the Syr Darya is so polluted that water from it should not be used for drinking or for irrigation.“ • In the past few years, the World Bank has funded a dam and restoration project with the goal of improving the health of the Syr Darya and increasing the flow into what's left of the North Aral Sea. Photograph by Carolyn Drake • For Panos Pictures
  62. 62. Rio Grande River • One of the largest rivers in North America, the 1,885-mile (3,033-kilometer) Rio Grande runs from southwestern Colorado to the Gulf of Mexico. It defines much of the border between Texas and Mexico. But the once grande river is looking more poco these days, thanks to heavy use on both sides of the border. • Less than a fifth of the Rio Grande's historical flow now reaches the Gulf. For a few years in the early 2000s, the river failed to reach the coast entirely. All that separated the United States from Mexico was a beach of dirty sand and an orange nylon fence. • Here, the river defines the international border across the Adams Ranch near Big Bend National Park. Photograph by Ian Shive For Aurora Photos/Alamy
  63. 63. Rio Grande River • Algae colors the confluence of the Rio Grande and Arroyo San Carlos. • The population in the Lower Rio Grande Valley is exploding in both the United States and Mexico, driven by NAFTA-era factories and agricultural productivity. But by the time it reaches Matamoros, the river's level is so low that it often falls below the Mexican city's intake pipes. Farmers in Texas say they lose $400 million annually due to lack of irrigation water. • The region's wetlands, once critical stopover points for migrating birds, are getting choked off. All these problems are made worse by the decadeslong drought gripping the region. Photograph by Jack W. Dykinga For National Geographic
  64. 64. Yellow River • The Yellow River is the second longest in China, after the Yangtze, and the sixth longest in the world, with a course of 3,395 miles (5,464 kilometers). The Yellow River was the cradle of the earliest known Chinese civilization, and it has a long and complex history in the region. Numerous floods over the centuries resulted in catastrophic loss of life, including a flood in 1931 that killed one to four million people. • Since 1972, the Yellow River has frequently run dry before reaching the sea, thanks to extensive diversion, largely for agriculture. In 1997, the lower Yellow River did not flow for a whopping 230 days. Such a dramatic decrease in water has choked off the ecologically rich delta, which is also eroding due to loss of silt. • In recent years, the Chinese government has taken steps to restore some of the water's flow, denying some farmers use along the way. Photograph by Christian Kober For Robert Harding World Images
  65. 65. Teesta River • The Teesta River flows 196 miles (315 kilometers) through the Indian state of Sikkim and into the Brahmaputra River in Bangladesh. It starts in the Himalaya, where it is fed by snowmelt, and then carves its way through temperate and tropical valleys. • The Teesta is often called the lifeline of Sikkim, but in recent years it has been so tapped for irrigation and other uses that it has largely dried up. Fishermen are no longer able to make a living along its banks, and thousands of farmers have lost their water supply. • Even so, India is going ahead with plans to build a new series of dams along the Teesta, in a bid to generate electricity. Geologists warn that the weight of sediments that pile up as a result could trigger earthquakes in the seismically active area. • "Reasonable sharing of Teesta water is the only way to improve the ecological situation in the area," Indian environmental activist Golam Mostafa of CAMP told The Daily Star. "But it is still to be achieved despite a few meetings between Bangladesh and Indian governments," he said. Photograph by John Stanmeyer, VII/Corbis For National Geographic
  66. 66. Murray River • Some experts have warned that the troubles in Australia's Murray River Basin may be a harbinger of what other water-stressed regions can expect in a warming world, with rising human population. The Murray is Australia's longest and arguably most important river, stretching for 1,476 miles (2,375 kilometers) from the Australian Alps, across the inland plains to the Indian Ocean near Adelaide. • As a result of irrigation, the Murray Valley is Australia's most productive agricultural zone, and is widely known as the nation's food bowl. However, withdrawals have resulted in rising salinity, which threatens that agricultural productivity. The river is also the source of 40 percent of Adelaide's drinking water and most of the water for many smaller towns along its length. • Disruptions and diversions have reduced the flow so much that the mouth of the river closed due to silt formation at the beginning of the 21st century. Only dredging is able to keep the final channel open, both to the sea and the lagoon of nearby Coorong National Park. • Pictured is Lake Hume, a reservoir that was only at 19.6 percent capacity when this photo was made. By the end of the summer of 2009 it dropped to 2.1 percent capacity.
  67. 67. Murray River • The mouth of the Murray River, where a dredge keeps the pathway open. • The Murray faces other serious environmental threats, including polluted runoff, especially from farms in four Australian states, and introduction of invasive species, especially the European carp. • Similar problems affect the Darling River, which flows into the Murray at Wentworth. The Darling is known as a main waterway of the outback, but some years it is so tapped and affected by drought that it hardly flows at all. Photograph by Amy Toensing For National Geographic
  68. 68. Solution?!
  69. 69. Solution?! • Environmental racism is the pattern by which environmental hazards are greatest in proximity to poor people, particularly poor minorities. In part, it is a deliberate strategy by factory owners and powerful officials. • Looking Ahead: Toward a Sustainable World. – – – – – – We need to develop an ecologically sustainable culture, a way of life that meets the needs of the present generation without threatening the environmental legacy of future generations. Combat poverty by promoting economic development and job creation. Involve local community in local government. Reduce air pollution by upgrading energy use and alternative transport systems. Create private-public partnerships to provide services such as waste disposal and housing. This calls for three basic strategies: » » » » We must bring world population growth under control. We must conserve finite resources. We must reduce waste. Will People Overwhelm the Earth?
  70. 70. Summary • • • The promise of jobs and prosperity, among other factors, pulls people to cities. Half of the global population already lives in cities, and by 2050 two-thirds of the world's people are expected to live in urban areas. But in cities two of the most pressing problems facing the world today also come together: poverty and environmental degradation. Poor air and water quality, insufficient water availability, waste-disposal problems, and high energy consumption are exacerbated by the increasing population density and demands of urban environments. Strong city planning will be essential in managing these and other difficulties as the world's urban areas swell. Threats – Intensive urban growth can lead to greater poverty, with local governments unable to provide services for all people. – Concentrated energy use leads to greater air pollution with significant impact on human health. – Automobile exhaust produces elevated lead levels in urban air. – Large volumes of uncollected waste create multiple health hazards. – Urban development can magnify the risk of environmental hazards such as flash flooding. – Pollution and physical barriers to root growth promote loss of urban tree cover. – Animal populations are inhibited by toxic substances, vehicles, and the loss of habitat and food sources. – Plant trees and incorporate the care of city green spaces as a key element in urban planning.
  71. 71. Summary • Environmental racism is the pattern by which environmental hazards are greatest in proximity to poor people, particularly poor minorities. In part, it is a deliberate strategy by factory owners and powerful officials. • Looking Ahead: Toward a Sustainable World. – – – – – – We need to develop an ecologically sustainable culture, a way of life that meets the needs of the present generation without threatening the environmental legacy of future generations. Combat poverty by promoting economic development and job creation. Involve local community in local government. Reduce air pollution by upgrading energy use and alternative transport systems. Create private-public partnerships to provide services such as waste disposal and housing. This calls for three basic strategies: » » » » We must bring world population growth under control. We must conserve finite resources. We must reduce waste. Will People Overwhelm the Earth?
  72. 72. Summary
  73. 73. Return to Basics…