The document discusses environmental issues in South America, including: 1. Rural issues like deforestation, grassification, and problems with agriculture lands. 2. Urban challenges in cities like Mexico City related to air pollution, water pollution, and subsidence. 3. Major physical features including the Andes mountains, uplands, shields, river basins and lowlands which impact climate, settlement patterns, and economic activities. 4. Climate patterns vary regionally from tropical humid to desert, and phenomena like El Niño impact weather. 5. Global warming threatens to increase temperatures and lower rainfall in some areas, cause glacier retreat, spread diseases, and intensify weather events.

1. South America
Environmental Geography

3. • Introduction & Rural environmental
issues
1
• 2 Urban environmental challenges
• 3 Western mountains & Eastern shields
• 4 River basins & Lowlands
• 5 Climate patterns
• 6 Latin America & Global warming

4. Challenge to S.A. goverments
The need for
economic
development
The need for
environmental
conservation

5. Rural environmental issues
Declining forests & Degraded farmlands
Deforestation
& Biological
loss
Agriculture
Wood
export
Search for
gold
Permanent
settlement

6. Grassification
▪ Definition: The conversion of tropical forest into pasture
▪ A practice that contribute to forest loss
▪ In Southern Mexico, Central America, Brazillian Amzon,
development policies encouraged deforestation to make
room for cattle
▪ However, ranching in remote areas is seldom
economically self-sustaining

7. Problems on Agricultural lands
Pressure to modernize agriculture causes many environmental problems
▪ Adopting new hybrid species of corn, beans, etc -> native species disappearance ->
genetic diversity erosion
▪ Chemical fertilizers & pesticides -> contaminating soil & water; causing severe
health issues
▪ Failure/lack of soil conservation measures -> soil erosion & fertility decline ->
production decreased
▪ Urban expansion claims much of the best farmlands

8. Urban environmental
challenges

9. ▪ Latin America’s most pressing environmental issues are found in its urban areas
▪ Mexico City is a good example of the kinds of environmental challenges facing
modern Latin American cities
A picture of Mexico City taken by BBC

10. I. The Valley of Mexico’s Environmental Problems

11. The Valley of Mexico
▪ Cradle of Aztec civilization
▪ Site of Mexico city with a pop. of 18 mil
people
▪ Has the ideal environmental settings to build a city, though it’s currently severely
degraded

12. Mexico City’s most pressing problems
▪ Air quality
▪ Water pollution
▪ Subsidence (soil sinkage)

13. 1. Air Quality
▪ A major issue since the 1960s
▪ Caused by city growth, number of
cars & physical settings
▪ Pollution high enough to cause a gray
cloud hanging above the city

14. The city’s settings play a major role in
creating pollution and enlarging it
▪ The city sits in a bowl 2250 meters
above sea level
▪ A layer of warm air traps a layer of
cold air near the surface
(thermal/temperature inversion)
▪ The cold air layer is filled with
pollutants
▪ Cause a great deal of troubles for
the inhabitants

15. Steps taken to improve the situation
Starting from 1980s: reduce emissions from
factories and cars
▪ Unleaded gas available for the 4mil cars in the
metropolitan areas
▪ Cars for Mexican markets must have catalytic
converters
▪ Worst polluting factories closed
▪ Program restricting driving was expanded
▪ Expanded low-emission Metrobus system, build
suburban train system
=> No longer ranks in the top polluted cities in the
world, cut pollutants by half

16. 2. Water Pollution
▪ One of the most relentless environmental
problems
▪ Most water – which used to fill the valley in
lakes – were drained for agriculture
▪ Less surface water => more wells were dug to
use the basin’s fresh water aquifer
▪ Evidenced that the aquifer is being overdrawn
and at risk of contamination
▪ To reduce reliance on underground water, the
city pumps water from 160km away

17. 3. Subsidence (soil sinkage)
▪ Mexico is sinking, as the metropolis
pumps water from its aquifer
▪ Impacted the whole city
throughout:
- Building foundations destroyed
-Water and sewer lines rupture
- Damaged landmarks
▪ Water no longer being pumped
from the city => slowed the sinking
to 2.5cm a year compared to 50cm
at its worst

18. Impact of sinkage
The Cathedral leaning to the left after centuries
of subsidence
Cracks in building foundations

19. II. Ongoing Urban Challenges and Responses
▪ For most Latin Americans, most pressing
environmental problems = air pollution,
inadequate water and garbage removal
▪ They live better than their counterparts in Asia
and Africa but still need expensive remedies
for env. problems
A squatter settlement in Mexico City

20. Industrialization = major cause for pollution, but government tends to go easy on
enforcing env. laws
=> in the worst cases, it poses a serious threat to people and the environment
Cubatão, São Paulo, Brazil, once called the
valley of death due to pollution

21. ▪ Not far from Cubatão is Curitiba, the capital of Paraná
state – a model city also called the “Green City” for its
planning decisions
▪ Significantly less polluted than other similar sized cities
▪ City planners built drainage, canals for floodings, set
aside other areas as parks early during the 1960s
▪ Public transportation = top priority
▪ Low tech but effective recycling program
=> Designing with nature makes sense both ecologically
and economically
Curitiba City, Brazil

22. Western Mountains and Eastern Shields
▪ The Andes
▪ Relatively young, 5,000 miles long; 30 peaks over 20K feet
▪ Active volcanism and earthquake
▪ Contain valuable metals and minerals

23. Western Mountains and Eastern Shields
▪ The Andes is divided
into northern, central
and southern
component.
▪ The northern Andes: 3
mountains ranges

24. Western Mountains and Eastern Shields
Altiplano: treeless, elevated plain
in Peru and Bolivia, the floor
ranges from 11,800 feet to 13,000
feet
Two high-altitude lakes: Lake
Titicaca and Poopó

25. Western Mountains and Eastern Shields
▪ The southern Andes: the highest peaks, Aconcagua, 23,000 feet,
mountains are lower

26. Western Mountains and Eastern Shields
The Uplands of Mexico and Central America
▪ The Mexican Plateau and the Volcanic Axis of Central
America: The most important Latin America uplands
▪ Most major cities and population found her

27. Mexico City

28. Guadalajara Puebla

29. Western Mountains and Eastern Shields
▪ Rich volcanic soils, domestic and export crops
▪ Agriculture land that yield beef, cotton and coffee

30. Western Mountains and Eastern Shields
▪ The Shields: 3 major shields
▪ The Guiana shield
▪ The Brazilian shield: the largest shield, more important,
rich of fertile red soils, elevated basins ( city of São
Paulo-largest urban conglomeration in SA), commercial
agriculture

31. Western Mountains and Eastern Shields
▪ The low-lying Patagonian shield: treeless, covered by scrubby steppe vegetation,
offshore oil production

32. River Basin and Lowlands

33. Within these basins are
vast interior lowlands:
▪ The Llanos
▪ The Amazon
lowlands
▪ The Pantanal
▪ The Chaco
▪ The Pampas

34. Settlement
Natural
resources
Intense
economic
activities

35. Amazon Basin
▪ Geography:
- The largest river system in
the world by volume and
area, the second longest by
length (2.4 million square
miles)
- There is no real dry season

36. The Amazon
contributes 20% of
all freshwater
discharged into
the ocean.

37. Amazon Basin
▪ Amazon Basin draws from 8 countries
An ideal network to integrate the northern half of South America

38. Population
▪ Most of the older
settlements are found on
the floodplain, where
natural levees reach heights
of 20 feet (6 meters)
▪ Roughly 15m people (about
8% of the country’s total
population) live in Brazilian
Amazon

40. PLATA BASIN
▪ The region’s second largest watershed
▪ Make up from 3 major rivers:
+ The Paraná
+ The Paraguay
+ The Uruguay.

41. ▪ Economically productive:
especially soybean production

42. The Chaco
(arid area)
The
Pantanal
(inundated
lowlands)
Support
livestock

43. Contains major dams: Itaipú - region’s largest
hydroelectric plant
-Enhance Panará River’s capacity for barge and boat
traffic.

44. Orinoco Basin
▪ The third largest river basin
▪ Located in northern South America

45. Population
North of the basin: 90% of
Venezuela’s population
The Industrial
developments between
Ciudad Guayana and
Ciudad Bolívar:
many cities located.

46. Llanos (grasslands)
▪ Support large cattle ranches
▪ Become a dynamic area of petroleum
production for Colombia and
Venezuela.

47. Climate patterns
In tropical Latin America average
monthly temperatures show little
variation. Precipitation pattern do
vary, however, and create distinct
wet and dry seasons.

48. ▪ The tropical
lowlands classified
as tropical humid
climates that
support forest or
savanna, depending
on the amount of
rainfall.

49. ▪ Extreme aridity  region’s desert climates

50. ▪ Midlatitude climates, with hot summers and cold
winters, prevail in Argentina, Uruguay, and parts of
Paraguay and Chile.
The Andean range over the province of Santa Cruz – Argentina.

51. Altitudinal Zonation
▪ Altitudinal zonation has
practical applications.
▪ The environmental lapse
rate.

52. The concept of
altitudinal zonation
is most relevant for
the Andes, the
highlands of Central
America, and the
Mexican Plateau.

53. El Nino
▪ Occurs when a warm Pacific current arrives along the
cold coastal waters of Ecuador and Peru in December,
around Christmastime
▪ Happens every few years
▪ Produces torrential rains, signaling the arrival of an El
Nino year
▪ El Nino’s impacts.

55. Global Warming
Global warming - one of the dominant issues in Latin America

56. 8% of the world’s population

57. ▪ 6-8% of global greenhouse
emissions
▪ Rate of greenhouse
emissions growth : lower
than in all other regions,
except for Sub-saharan
Africa

58. Reasons for low greenhouse emissions growth rate
▪ Lower average energy consumption
▪ Higher reliance on renewable energy
▪ Greater dependence upon public transportation

60. Highland areas :
Higher temperature and Lower rainfall

61. Retreat of Andean glaciers

62. Retreat of Andean glaciers

63. Dengue fever

64. Dengue is now widespread in more than 100 tropical
and sub-tropical around the world

65. • Impact the frequency and strength of El
Nino cycles
=> Increased flooding in Western South
America
=> Declining fishery off the coast of Peru
and Chile
• Increasing hurricane intensity

66. Several unprecedented weather-related
events in the recent past
• Intense rainfall in Venezuela (1999, 2005)
• Amazon drought (2005) in Brazil
• Hailstorms in Bolivia (2002) and Greater
Buenos Aires area (2006)
• The devastating hurricane Katrina in 2004

67. Thanks for listening