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Urban Development. Module 6 Lesson 4. Urbanization – an increase in the ratio or density of people living in urban areas rather than in rural areas As urban populations have grown, many small towns have grown together and formed large urban areas called metropolitan areas. Urbanization.
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Urban Development Module 6 Lesson 4
Urbanization – an increase in the ratio or density of people living in urban areas rather than in rural areas • As urban populations have grown, many small towns have grown together and formed large urban areas called metropolitan areas. Urbanization
Patterns of Urbanization and Growth • Proportion of global population living in urban areas is increasing • Number of large cities is mushrooming • Urbanization and urban population are increasing rapidly in developing countries • Poverty is becoming increasingly urbanized as more poor people migrate from rural to urban areas
Urban Sprawl- outward expansion of low-density development on the edges of cities and towns that encourages dependence on cars • Suburbs – housing and associated commercial buildings on the boundary of a larger town Urban Sprawl
When land is available and affordable, urban areas tend to sprawl outward because: • Federal government loan guarantees stimulated the development of suburbs. (post war) • Low-cost gasoline and government funding of highways encourages automobile use. • Tax-laws encourage home ownership. • Most zoning laws separate residential and commercial use of land. Urban Sprawl
Centers of: • Economic development • Innovation • Education • Technological advances • Jobs • Industry, commerce, transportation Urbanization Has Advantages Has Advantages
Urban populations live longer in many parts of the world • Have better access to medical care, education, social services • Lower infant mortality • More recycling programs (more economically feasible) • A more concentrated population means higher population % in a lower land % Concentrating people in cities can help preserve biodiversity in rural areas Urbanization Has Advantages
Most cities are not self-sustaining and have huge ecological footprints • Few trees, shrubs, etc. that would otherwise absorb air pollutants and provide oxygen • Most cities have water supply problems • Concentrate pollution and health problems • Noise pollution- impairs or interferes with hearing, causes stress, hampers concentration, etc. • Altered climate and experience light pollution • Loss of farmland and natural habitat as cities expand Urbanization Has Disadvantages
Heat island – an area in which the air temperature is generally higher than the temperature of surrounding rural areas • Heat is generated by the infrastructure that makes a city run. • Cities have less wind to move warm air out • Building materials absorb and hold heat • More cars and industry increase emissions • Roads absorb and retain heat longer than vegetation does. Urban Heat Island Effect
Scientists are beginning to see that heat islands can affect local weather patterns. Hot air rises over a city, cooling as it rises, and eventually produces rain clouds. • In Atlanta, Georgia, and many other cities, increased rainfall is a side effect of the heat island effect. Urburn Heat Island by Joanna Kosmider, public domain Urban Heat Island Effect
Most Polluted Cities in the World Delhi, India (annual mean PM2.5, ug/m3: 153) Patna, India (annual mean PM2.5, ug/m3: 149) Gwalior, India (annual mean PM2.5, ug/m3: 144) Raipur, India (annual mean PM2.5, ug/m3: 134) Karachi, Pakistan (annual mean PM2.5, ug/m3: 117) Peshawar, Pakistan (annual mean PM2.5, ug/m3: 111) Rawalpindi, Pakistan (annual mean PM2.5, ug/m3: 107) Khorramabad, Iran (annual mean PM2.5, ug/m3: 102) Ahmedabad, India (annual mean PM2.5, ug/m3: 100) Lucknow, India (annual mean PM2.5, ug/m3: 96) http://www.ibtimes.co.uk/world-environment-day-10-most-polluted-cities-world-1504260
Noise pollution is becoming a greater problem as people begin to move into formally unpopulated areas. Sound is measured in decibels (dB). The scale is logarithmic. 30 dB has ten times more energy than 20 dB. Exposure to sound above 85 dB can cause permanent hearing loss, while pain is experienced above 120 dbB (so turn your earbuds down!!) • Light pollution has become a major problem in large cities. • The excess light affects the natural cycles of animals, including humans, and even interferes with astronomical studies. • Light pollution from some cities is so great, stars can not be seen at night as the sky is never fully dark Light vs Noise Pollution Photo: NASA
Urban Decay • Infrastructure – the basic facilities of a country or region, such as roads, bridges, sewers, and railroads • Urban crisis – When more people live in a city than its infrastructure can support, the living conditions deteriorate • …a process where a once-functioning city or suburb falls into disrepair. • It is commonly followed by or characterized by: • High crime rates • Unemployment • Social disregard • Abandoned buildings • Unappealing landscapes. The Urban Crisis
Set of policies and activities related to potential uses of land that is put in place before an area is developed Conventional Land Use Planning: • Based on considerable future growth and encouraging all economic development • Revenues: property taxes make up 90% of local government revenue in the U.S. Ecological- ‘smart growth’ Planning: • anticipate present and future needs and problems • complex process, not often done for many reasons Land-Use Planning
Built and redesigned for people not cars • Use renewable energy resources • Prevent pollution and reduce waste • Recycle, reuse and compost municipal waste • Wastewater gardens • Protect and support biodiversity (mimics natural metabolism of nature) • Urban gardens; farmers markets • Efficient energy and matter use The Ecocity Concept (Green Cities):