urbanism and architecture

1. ARCH 5351
ECOLOGICAL ARCHITECTURE & URBANISM
Lecture-4 Dep’t of Architecture & Urban Planning Ar.Gagan Jain

2. CONTENTS –
 Global Environmental issues
 Rain water Harvesting
 Water and Energy Conservation
 Ecological and social dimensions of Urban Forests
 Watershed Management
 Environmental Impact Assessment
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3. Global Environmental Issues
 Green House Effect and Global Warming
 Bio Diversity
 Desertification
 Ozone Layer Depletion
 Acid Rain
 Nuclear Disasters
 Oil pollution
 Hazardous Waste
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4. Major Global Environmental Issues
 Increased human activity, urbanization, industrialization have led to rapid
deterioration of the environment.
 The developmental discrepancies in different regions of the world pose a
serious threat to our common global environment. Consequently, we are
confronted with complex environmental issues deserving attention. The
important global environmental issues are:
 • green house effect and global warming
 • biodiversity loss
 • desertification
 • depletion of ozone layer
 • acid rain
 • oil spills
 • dumping of hazardous wastes
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5. Green House Effect and Global Warming
 What is the green house effect?
 Global warming and green-house effect
(Global warming affects both living and non-living components of our
planet.)
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6. Effect on climate
 Increased CO2 concentration in the atmosphere may increase
photosynthetic productivity of plants. This in turn produces more organic
matter. It may seem a positive effect. But, then
 Weeds may proliferate rapidly, and that too at the expense of useful
plants.
 Insects and other pests that feed on plants may also increase in number.
 Survival of other organisms gets affected.
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7. Strategies to cope with greenhouse effect
 We must take immediate steps to minimize global warming by reducing
emission of green house gases especially carbon dioxides. Following
steps would be useful in reducing emission/release of green house gases
into the atmosphere:
 Increased fuel efficiency of power plants and vehicles;
 Development/implementation of solar energy/non-fossil fuel alternatives;
 Halting deforestation;
 Supporting and undertaking tree-planting (afforestation);
 Reduce air-pollution.
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8. Bio Diversity
 Plants and animals of a region constitute biodiversity. Biodiversity is a natural
wealth essential for human survival.
Classification
 Biodiversity could be classified as -
 (a) Species biodiversity: It includes total number of different taxonomical or
biological species. There are several endemic species in Ethiopia.
 (b) Genetic biodiversity: It includes land traces; horticultural varieties; cultivers,
ecotypes (related types differing due to difference in the ecological condition);
all within a biological species.
 (c) Ecosystem biodiversity: It includes various biological zones, like lake, desert,
coast, estuaries, wetlands, mangroves, coral reefs etc.
Both flora and fauna, all over the world are under an assault from a variety of
indiscriminate human activities. These activities are often related to rapid growth
of human population, deforestation, urbanization and industrialization.
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9. Reasons for biodiversity loss
 Rapid decline of biodiversity is a result of various causes.
 Loss of Habitat
 Pollution
 Overuse
 Introduction to Foreign Species
 Environmental Degradation
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10. DESRTIFICATION
 Desertification is diminution or destruction of the biological potential of the land
which ultimately leads to the formation of desert.
 The land that has lost its productivity (ability to grow plants) is called a desert. A
desert landscape supports a very limited growth of sparse vegetation and
stunted growth of plants.
 Substantial part of earth’s 132.4 million sq km of terrestrial area is facing
desertification due to overexploitation and mismanage of land resources for
human activities.
 Some of the principal causes, which promote desertification, are:
 • over cultivation,
 • overgrazing,
 • deforestation, and
 • salt accumulation due to irrigation.
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11. OZONE LAYER DEPLETION
 Causes of ozone layer depletion
 Natural causes:
 Human activity related causes:
 Effect of O3-layer depletion
 Measures to prevent ozone (O3) layer depletion
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12. ACID RAIN
 Acid rain refers to any precipitation (rain, fog, mist, snow) that is more acidic
than normal.
 Acid rain is caused by atmospheric pollution from acidic gases such as sulphur
dioxide and oxides of nitrogen emitted from burning of fossil fuels.
 Acid rain is formed when the air that contains acidic gases emitted mostly from
power plants industries and automobiles, combines with the rain drops.
 The acid rain affect ecosystems in diverse ways
 Therefore, emission of sulphur dioxide oxide and of oxides nitrogen into the
atmosphere can lead to the formation of acid rain.
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13. Harmful effects of acid rain
 Acid precipitation affects both aquatic and terrestrial organisms. It also
damages buildings and monuments.
 (i) Effects on aquatic life
 (ii) Effect on terrestrial life
 (iii) Effects on forests
 (iv) Effect on buildings and monuments
Strategies to cope with acid rain
 Any procedure that shall reduce, minimize, or halt emission of sulphur
and nitrogen oxides into the atmosphere shall control acid rain.
 Use of low sulphur fuel or natural gas or washed coal (chemical washing
of pulverized coal) in thermal plants can reduce incidences of acid rain.
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14. NUCLEAR DISASTERS
 Nuclear energy offers an alternative to many of environmental and
social problems. But, it also introduces serious problems of its own.
 Though environment friendly, it is not yet economically affordable.
 Nuclear plants pose potential danger of accidents that may release
hazardous radioactive materials into the environment.
 The problems are two fold:
 (i) nuclear disasters and fall out and
 (ii) safe disposal of nuclear waste generated by nuclear plants.
Some of the major nuclear disasters are given in table
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15. OIL POLLUTION
 Oil pollution refers to layers of oil on water bodies. Oil spills are most
glaring of all oceanic pollution.
 Every marine transport vessel poses a potential danger of oil spill.
 A. Causes of oil spill
 B. Impact of oil spill on marine life
 C. Impact of oil spills on terrestrial life
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16. HAZARDOUS WASTE
 Any substance that is present in the environment or released into the
environment causing substantial damage to public health and welfare of the
environment is called hazardous substance.
 Any substance that could have serious irreversible health effects from a single
exposure is called very hazardous substance.
 Any hazardous substance could exhibit any one or more of the following
characteristics:
 • toxicity
 • ignibility
 • corrosivity
 • reactivity (explosive)
 Thus, any waste that contains hazardous or very hazardous substance is called
hazardous waste.
 Hazardous wastes can originate from various sources such as: house-hold, local
areas, urban, industry, agriculture, construction activity, hospitals and
laboratories, power plants and other sources.
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17. Summary
• All of us are inheritors of common global environment.
• All of us are responsible for its growing deterioration. If the deterioration exceeds
a limit, it shall be a dangerous place to live in.
• Pollution, ozone-hole, greenhouse effect, desertification, loss of biodiversity, oil
spills, nuclear disasters, hazardous waste management, are some of the global
environmental problems that need immediate collective attention.
• Increased human activity, urbanisation, industrialisation are led to rapid
deterioration of the environment. This has severely affected the life supporting
system.
• A green house is a glass chamber in which plants are grown to provide them
warmth by trapping solar radiations and heat. Infrared rays pass through glass and
the heat generated there from, cannot escape out of the glass chamber.
• Increased fuel efficiency in vehicles; development/implementation of solar
energy/nonfossil fuel alternatives; halting further deforestation; support and
undertake tree planting (afforestation); reduce air-pollution are the strategies for
coping with green house effect.
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18. Summary
• Flora and fauna of a region constitute biodiversity. It is considered as natural
wealth of the nature.
• Biodiversity can be classified into three types i.e. species biodiversity, genetic
biodiversity and ecosystem biodiversity.
• Loss of habitat, pollution, and overuse, introduction of foreign species and
contribution of other environmental degradation factors are the reasons of
biodiversity loss.
• Desertification is diminution or destruction of the biological potential of the land
which ultimately leads to desert. Over cultivation, overgrazing, deforestation and
salting sue to irrigation are principal causes for desertification.
• Acid precipitation affects both aquatic and terrestrial life. It also damages
buildings and monuments.
• We all need to cooperate at individual, domestic, local. National and
international level to maintain our environment clean and sustainable.
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19. RAIN WATER HARVESTING

20. Water Conservation & Harvesting
Total water management for sustainable development?.

21. Water Conservation
 Important step for solutions to issues of water and environmental
conservation is to change people's attitudes and habits
 Conserve water because it is right thing to do!.
 What you can do to conserve water?
 Use only as much water as you require. Close the taps well after
use. While brushing or other use, do not leave the tap running,
open it only when you require it. See that there are no leaking
taps.
 Use a washing machine that does not consume too much
water.
 Do not leave the taps running while washing dishes and clothes.

22.  Install small shower heads to reduce the flow of the water.
 Water in which the vegetables & fruits have been washed -
use to water the flowers & plants.
 At the end of the day if you have water left in your water
bottle do not throw it away, pour it over some plants.
 Re-use water as much as possible
 Change in attitude & habits for water conservation
 Every drop counts!!!
Water Conservation

23. Rain Water Harvesting?
• Rain Water Harvesting RWH- process of
collecting, conveying & storing water from
rainfall in an area – for beneficial use.
• Storage – in tanks, reservoirs, underground
storage- groundwater
• Hydrological Cycle

24. • RWH - yield copious amounts of water. For an average
rainfall of 1,000mm, approximately four million liters of
rainwater can be collected in a year in an acre of land (4,047
m2), post-evaporation.
•As RWH - neither energy-intensive nor labour-intensive
•It can be a cost-effective alternative to other water-
accumulating methods.
• With the water table falling rapidly, & concrete surfaces
and landfill dumps taking the place of water bodies, RWH is
the most reliable solution for augmenting groundwater level
to attain self-sufficiency
Rain Water Harvesting?

25. • Roof Rain Water Harvesting
• Land based Rain Water Harvesting
• Watershed based Rain Water harvesting
•For Urban & Industrial Environment –
•Roof & Land based RWH
•Public, Private, Office & Industrial buildings
•Pavements, Lawns, Gardens & other open
spaces
RWH – Methodologies

26. Rain Water Harvesting– Advantages
1.Provides self-sufficiency to water supply
2.Reduces the cost for pumping of ground water
3.Provides high quality water, soft and low in minerals
4.Improves the quality of ground water through dilution when recharged
5.Reduces soil erosion & flooding in urban areas
6.The rooftop rain water harvesting is less expensive & easy to
construct, operate and maintain
7. In desert, RWH only relief
8. In saline or coastal areas & Islands, rain water provides good
quality water

27. Rain Water Harvesting– Techniques
There are two main techniques of rain water harvestings.
 Storage of rainwater on surface for future use.
 Artificial Recharge to ground water.
Artificial recharge to ground water is a process by which the ground water
reservoir is augmented at a rate exceeding that obtaining under natural
conditions or replenishment.
Any man-made scheme or facility that adds water to an aquifer may be
considered to be an artificial recharge system.

28. COMPONENTS OF A RAINWATER
HARVESTING SYSTEM
A rainwater harvesting system comprises components of various stages -
transporting rainwater through pipes or drains, filtration, and storage in tanks
for reuse or recharge. The common components of a rainwater harvesting –
• Pits
• Trenches
• Dug wells
• Hand Pumps
• Recharge wells
• Recharge Shafts
• Lateral shafts with bore wells
• Spreading techniques

29. Environmental Impact
Assesment (EIA)

30. EIA
 Every country strives to progress ahead one aspect of progress is economic
development through manufacturing and trading.
 Every country builds industries which provide employment, serve the consumers
needs and help to generate revenue.
 Development projects in the past were undertaken without any consideration
to their environmental consequences.
 As a result rivers and lakes got polluted, air pollution reached at threatening
level and pilling of industrial wastes resulted in land degradation.
 Industrialization and economic growth provided material comforts and luxuries
of life but at the same time deteriorated the quality of life.
 In view of the colossal damage to environment by developmental activities
people are now concerned about the environmental impact of
developmental projects.
 EIA enables the decision makers to analyse the effect of developmental
activities on the environment, if any well before the developmental project is
implement.
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31. IMPORTANCE OF EIA IN RESPECT OF
ENVIORNMENTAL PROTECTION
 Unfortunately industrial development has had adverse impact on the environment.
 Most of the developmental activities such as building of dams, roads, airports, industries,
railway tracks, cities etc. use enormous amounts of natural resources as raw material
and they may generate waste, which is disposed off into the environment.
 Waste disposal causes damage to air, soil and water, and brings about depletion of
natural resources.
 The protection of the global environment is in the interest of all of us living on this planet.
 Various measures have been taken at national and international levels to correct a
number of environmental problems as you have already learnt in the previous lesson.
 In light of the above it is important to anticipate the likely environmental problems and
threats that may arise out of the proposed developmental activities and human
actions.
 Such an anticipation is termed “Environmental Impact Assessment” (EIA).
 EIA is tool that improves decision making and ensures that the project under
consideration is an acceptable option.
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32. THANKYOU