CIVIL & STRUCTURE DEPARTMENT

FACULTY OF ENGINEERING & BUILT ENVIRONMENT

THE NATIONAL UNIVERSITY OF MALAYSIA

REPORT OF PROJECT SUSTAINABLE URBAN PLANNING

SEMESTER II, SESSION 2012/2013

KKKH4284 SUSTAINABLE URBAN PLANNING

Assignment Title:

TASK 6

GLOBAL WARMING

Lecturer:

PROF. IR. DR. RIZA ARIQ ABDULLAH BIN O.K RAHMAT

Group Member:

NURSYAHIDA BINTI BAHARIN A128791

1.0 INTRODUCTION

Global climate change has already had observable effects on the environment. Glaciers have

shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and

trees are flowering sooner. Globally, sea levels rose four to ten inches in the last century.

Researchers expect sea levels to continue rising.

Climate change can increase or decrease rainfall, influence agricultural crop yields, affect

human health, cause changes to forests and other ecosystems, or even impact our energy supply.

Climate-related impacts are occurring across regions of the country and across many sectors of

our economy. Many state and local governments are already preparing for the impacts of climate

change through "adaptation," which is planning for the changes that are expected to occur.

A continuous flow of energy from the sun heats the Earth. Naturally occurring gases in

the atmosphere, known as greenhouse gases. The gases is includes carbon dioxide (CO2) then

trap this heat like a blanket, keeping the Earth at an average of 15 degrees Celsius to warm

enough to sustain life. The overuse of fossil fuels is increasing CO2 in the atmosphere, trapping

more and more heat and warming the Earth.

2.0 PROBLEM THAT OCCUR IN THE CITY

The city administrator has noticed that the mean sea level has been rising for the past 50 years.

The raising is small but over a long period of time it may cause problems in the city centre as the

level of that part of the city is quite low.

Our weather is always changing and now scientists are discovering that our climate does

not stay the same either. Climate, the average weather over a period of many years, differs in

regions of the world that receive different amounts of sunlight and have different geographic

factors, such as proximity to oceans and altitude.

The causes of climate change can be divided into two categories that are due to natural causes

and those that are created by man. 

a. Natural cause

There are a number of natural factors responsible for climate change. Some of the more

prominent ones are continental drift, volcanoes, ocean currents, the earth's tilt, and

comets and meteorites.

One of the detail causes are volcanoes. When a volcano erupts it throws out large

volumes of sulphur dioxide (SO2), water vapor, dust, and ash into the atmosphere.

Although the volcanic activity may last only a few days, yet the large volumes of gases

and ash can influence climatic patterns for years. Millions of tonnes of sulphur dioxide

gas can reach the upper levels of the atmosphere (called the stratosphere) from a major

eruption. The gases and dust particles partially block the incoming rays of the sun,

leading to cooling. Sulphur dioxide combines with water to form tiny droplets of

sulphuric acid. These droplets are so small that many of them can stay aloft for several

years. They are efficient reflectors of sunlight, and screen the ground from some of the

energy that it would ordinarily receive from the sun. Winds in the upper levels of the

atmosphere, called the stratosphere, carry the aerosols rapidly around the globe in either

an easterly or westerly direction. Movement of aerosols north and south is always much

slower. This should give you some idea of the ways by which cooling can be brought

about for a few years after a major volcanic eruption

b. Human cause

The overwhelming body of scientific evidence demonstrates unequivocally that the earth

is warming. Climate change is happening, it is caused in large part by human activity, its

impacts are beginning to be experienced and these damaging effects will only increase in

the decades ahead. Green house gas emissions come from cars, power plants, and other

human activities rather than natural variations in climate that are the primary cause of

contemporary global warming. Due largely to the combustion of fossil fuels, atmospheric

concentrations of carbon dioxide (CO2), the principal human-produced greenhouse gas,

are at a level unequaled for at least 800,000 years. The greenhouse gases (GHGs) from

human activities are trapping more of the sun’s heat in the earth’s atmosphere, resulting

in warming.

Carbon dioxide and other GHGs always have been present in the atmosphere,

keeping the earth hospitable to life by trapping heat and warming our atmosphere. Yet,

since the industrial revolution, emissions of these gases from human activity have

increased steadily, trapping more heat and amplifying the greenhouse effect. Since pre-

industrial times, atmospheric CO2 concentrations have increased by 40 percent, and

concentrations of other GHGs have grown significantly as well. As a result, global

average temperatures have risen both on land and in the oceans, with observable impacts

already occurring that presage increasingly severe changes in the future. Polar ice is melt-

ing at record rates.

The pressure for new housing and current policies that prioritise the regeneration

of brown field land, much of which is already at risk of flooding, may well mean more

new development within the floodplain.

Increasing urbanisation and higher densities of development have reduced the

amount of natural soak-away available and strained existing drainage infrastructure.

People and properties that are not within currently recognized and defined floodplains are

increasingly at risk of flooding, usually from surface water.

The sources of flooding:

1. Tidal Flooding

Both sea and river defences may be overtopped or breached by a combination of low

pressure weather systems and peak high tides. Storms with high wind speeds cause tall

and powerful waves and low pressure fronts cause sea levels to rise above normal levels.

High tide levels vary through the lunar and solar cycle and when superimposed upon

other tidal variations exceptionally high tides result.

2. Fluvial Flooding

Flooding occurs in the floodplains of rivers when the capacity of water courses

ismexceeded as a result of rainfall or snow and ice melts within catchment areas further

upstream. Blockages of water courses and flood channels or tide locking may also lead to

ponding and rising water levels. River defences may then be overtopped due to increased

water levels, or breached by large objects.

3. Ground Water

Low lying areas sitting over aquifers may periodically flood as ground water levels rise.

This type of flooding is often seasonal and therefore can be forecasted with good

accuracy. It is often slow in its onset.

4. Pluvial Flooding

Surface water flooding is caused by rainwater run-off from urban and rural land with low

absorbency. Increased intensity of development in urban areas has given rise to land with

a larger proportion of non-permeable surfaces, a problem often exacerbated by

overloaded and out-dated drainage infrastructure. These circumstances, combined with

intense rainfall, can give rise to localised flooding.

This sort of flooding often occurs outside of recognised floodplains and because it

is caused by quite localised weather conditions it is very difficult to forecast. Its onset can

also be very rapid, and the level of flooding very severe.

5. Flooding from Sewers

Flooding from sewers can occur where there are combined storm and foul sewers and

their capacity is exceeded due to large amounts of surface water run-off in a short time.

Poor cleaning and maintenance can lead to blockages that can also cause local flooding.

This type of flooding is hard to predict, has significant sanitary consequences for those

affected, and can occur very rapidly.

6. Flooding from Man-made Infrastructure

Canals, reservoirs and other man-made structures can fail causing flooding to areas

downstream. Industrial activities, water mains and pumping stations can also give rise to

flooding due to failure.

3.0 IMPACT OF THE CLIMATE CHANGE EFFECT THE SEA LEVEL

While there are obviously many challenges to projecting future sea level rise, even a

seemingly small increase in sea level can have a dramatic impact on many coastal environments.

Climate change will affect the coastal environments through sea-level rise and its associated

impacts, including more frequent storms and flooding, higher rates of beach erosion,

submergence of coastal wetlands, and saltwater intrusion. These stressors will put some coastal

developments at increasing risk of damage.

Coastal climate change effects include:

a. Coastal community flooding

Melting glaciers, ice fields and polar ice caps, plus warming ocean waters all contribute

to rising sea levels. Climate change is predicted to bring stronger storms with heavier

precipitation and higher wave conditions. This will increase the frequency and extent of

flooding.

b. Coastal erosion and landslides

Climate change is predicted to increase storm intensities and wave height in the Pacific

Ocean. More frequent, intense storms combined with higher overall sea levels will result

in higher coastal erosion rates and more storm damage. Coastal communities will face

increased property damage to infrastructure (such as roads and water treatment systems).

c. Seawater well intrusion

A higher sea level means saltwater may penetrate wells in low-lying communities. This

will reduce the availability of freshwater for coastal communities. Islands pose unique

challenges for ground water management. Island County’s ground water aquifers are

recharged only by rainfall. Some aquifers (such as those at or below sea level near

shorelines) are connected to saltwater. Portions of these aquifers may contain saltwater.

Seawater intrusion, the movement of marine saltwater into freshwater aquifers, could

become a serious problem.

d. Lost wetlands and estuaries.

Wetlands often occur in low-lying areas and rising sea levels may convert these valuable

habitats to deep water. Wetlands and estuaries:

Protect against flooding by absorbing excess water

Filter out pollutants

Stabilize shorelines, and

Provide important habitat for wildlife such as salmon and waterfowl (in freshwater

wetlands) or shrimp, crabs, salmon, terns and herons (in salt water estuaries).

e. Beach erosion

Beaches are continually changing as sand is shifted by waves, tides, and currents. Sea-

level rise and land subsidence contribute to beach erosion and the narrowing or

movement of barrier islands. With climate change, rates of beach erosion would double

or triple by the 2020s, increasing three to six times by the 2050s, and four to ten times by

the 2080s, relative to the first decade of the twenty-first century. Climate models project

an increase in storms, which would further contribute to beach erosion.

To compensate for losses from erosion, additional sand would have to be placed

on the beaches. Sand replacement, also called beach nourishment, may remain a viable

option through mid-century, but could become significantly more costly, particularly for

the high-end warming scenarios, by the end of the century.

The effects of flooding:

The effects of flooding from the sources outlined above are felt by various ‘receptors’. These

include, people, buildings, infrastructure, agriculture, open recreational space and the natural

world.

In extreme cases flooding may cause a loss of life. However, the social and emotional

costs from flooding can also be significant and are often widespread and indiscriminate in

flooded areas. These costs include: displacement from homes, the loss of personal valuables and

the ongoing fear and insecurity caused by the experience.

Potable water supplies may be lost or contaminated in a flood and this can have

immediate health effects upon people and animals.

The built environment may be damaged or destroyed as a result of flooding with high

repair costs and long periods required for reinstatement. The public realm is often badly affected

through damage and the deposit of potentially large quantities of debris. Land contamination

may also be transported and spread during flooding.

Vital infrastructure may also be damaged or disrupted. Electricity and gas supplies can be

interrupted to individual properties but also to wider communities if sub stations and

transformers themselves are flooded. Road links, railways, canals etc. may be blocked causing

disruption to the wider transport network, and accessibility severely disrupted for local

inhabitants, especially amongst those considered most vulnerable.

4.0 MITIGATION OF THE PROBLEM

Flood generation

Woodland offers a number of potential opportunities.

Research indicates that those provided by the higher water use by trees and improved

infiltration are largely restricted to the hillslope or small catchment scale.

There appears to be considerable scope for using woodland to reduce flood risk across a

range of scales, although success depends on better integration with other land uses as

part of a whole catchment approach to sustainable flood management.

1. Increased evaporation and reduced run-off.

Reduced net rainfall under woodland due to interception loss.

Reduced transpiration loss from forest but depends on soil available water.

Interception loss declines with rainfall intensity.

2. Increased soil infiltration

Soil infiltration rate high under well managed woodland due to good soil structure

and rooting, reducing direct water runoff.

3. Flow resistance

Tress, undergrowth and woody debris increase the hydraulic “roughness” of the

floodplain, slowing down the passage of flood flows.

Trees and woody debris direct or concentration flows, forming multiple channels and

backwater pools, enhancing flood storage.

Net effect is to delay and reduce the size of flood peak.

5.0 PLAN ACTION TO REDUCE FLOODING

Classified floods according to three categories that is flash flooding, riverine flooding and sea

level rise or storm surge. One mechanism by which increases in the costs of disasters is likely to

occur relates to the ‘sea change’ phenomenon.

Action for future generation:

1. State disaster planning legislation and policy need to be harmonious with state coastal

legislation and policy concerning flood disaster events and anticipated sea level rise levels to

avoid confusion for individuals, developers, councils and the legal system.

2. A mechanism should be initiated in local government development assessment processes,

either at the planning scheme or council decision making end, so that the total land infill

impacts are factored into the consideration of the approval of new developments, particularly

estates, in flood prone areas.

3. Use a cost-benefit analysis or other economic model to account for the greater costs incurred

to the council and subsequently rate paying residents from any disaster impacts on proposed

developments.

4. Ensure that new developments incorporate adequate measures so that they are built off the

ground but allow for water passage on ground levels.

5. Include a gradient overlay in the local government planning scheme.

6. Undertake research detailing the comprehensive costs from road outages due to flooding

including validating historic figures and future estimates, so that future flood mitigation and

road maintenance business cases can be presented to decision makers in government at the

state and federal levels.

7. Ensure that terminology is more specifically defined under the SPP 1/03 and ensure a greater

focus on the intended outcomes of the recommended processes. Use scenarios in the

rewriting of the SPP 1/03 to make it understandable to practitioners.

8. To design more resilient communities, create provisions that require flood damaged houses

to be rebuilt above the 1/100 ARI flood line and building materials such as plastic cladding

rather than timber cladding are used in houses located in floodplains.

9. Commence a campaign that assists individuals and businesses to consider the impacts of

climate change into their own risk assessments of property location purchases to transition

cost-sharing across individual, business and government sectors.

The Threat to Place-making and Good Design

Standard responses to the risk of flooding include flood defenses, barriers to flood pathways and

raising accommodation above the potential water level onto columns or stilts. These measures

are often not well integrated with the overall architecture and landscape design, resulting in poor

quality and badly functioning neighborhoods and streetscapes.

Flood barriers limit opportunities for linkage as they are often both physically and

visually isolating which can result in poor quality public and private spaces. Also, developments

characterized by empty undercrofts or dominated by car parking at ground level tend to lack

identity and a sense of neighborhood.

6.0 ADAPTATION TO CLIMATE CHANGES

The process of adaptation planning identifies a set of actions to decrease a system's vulnerability,

or increase its resilience, to the impacts of climate change. The main tool of adaptation planning

is the vulnerability assessment: an evaluation of a system's risk compared to its adaptive capacity

or ability to cope with climate change. Vulnerability assessments reveal where and which actions

are needed to improve resilience to risk factors. They can be geographic or systemic in nature.

For example, a vulnerability assessment for a city could include mapping future sea-level rise

and areas at risk of urban heat-island effects alongside demographic information to reveal which

populations may be most exposed to flooding or extreme heat. A vulnerability assessment for a

wastewater system might model the system's performance under a range of predicted future

storm intensities and sea levels to see whether infrastructure needs to be protected or moved and

where urban flooding is most likely to occur. Vulnerability assessments can be used to set

priorities for early-, medium-, and long-term actions, and to develop "trigger points" for decision

making in the future.

Adaptation strategies should be implemented according to future conditions, regular assessment,

and recalibration. This process, called adaptive management, is necessary because there is great

uncertainty about how fast the climate is changing and when the predicted effects may occur.

Natural-resource managers have long used adaptive management to plan for uncertainty in the

environment. It is an iterative process in which managers and scientists work together to consider

management strategies, predict their outcomes, implement actions, monitor conditions, and

adjust future actions accordingly.

In the near term, some adaptation strategies have benefits that can be realized today, and may be

things we are already working on to achieve other policy goals. Two examples of these "no-

regrets" adaptation strategies include energy efficiency and water conservation, both activities

that are valuable today and may be even more valuable in the event of future climate change. In a

way, agencies and utilities working in these areas are doing climate adaptation planning already.

But the severity and trajectory of climate change will require a thorough examination of goals,

targets, and programs in these areas to ensure that they are effective in the future under changed

conditions.

Physical strategies for sea-level rise

There is a continuum of strategies we can use to manage changing sea levels, ranging from

armoring the shoreline — keeping the sea out — to abandoning low-lying development

altogether. Among them:

barrier(s) or tidal barrage(s) to manage tidal flows in and out of THE Bay (at the Golden Gate

or in smaller, strategic parts of the bay)

coastal armoring with linear protection, such as levees and seawalls, to fix the shoreline in its

current place

elevated development in which the height of land or existing development is raised and

protected with coastal armoring

floating development on the surface of the water, or that which may be floated occasionally

during a flood, making it largely invulnerable to changing tides

floodable development designed to withstand flooding or to retain stormwater

living shorelines with wetlands that absorb floods, slow erosion, and provide habitat

managed retreat that safely removes settlement from encroaching shorelines, allowing the

water to advance unimpeded, and bans new development in areas likely to be inundated

Governance of sea-level rise

Many public agencies have responsibility for managing the challenges of climate change. Water

supply and wastewater agencies will have to deal with changes in flow, facilities at risk, and

saltwater intrusion into intake systems. Airports and ports will have to deal with shoreline

infrastructure that is not at the right height. Transit and transportation agencies will have to deal

with roads, railways, and subways that are vulnerable to flooding. Parks, planning, and

redevelopment agencies will have to figure out how to deal with floodwater in residential

neighborhoods, especially in those neighborhoods that are least prepared to cope with new risks.

Managing infrastructure

Infrastructure — the physical fabric of functioning cities — is at risk from climate-change

hazards, especially sea-level rise. Roads, mass transit, airports, bridges, ports, energy generation

and distribution facilities, sewer systems, and water systems suffer already from underinvestment,

making certain assets even more at risk of weather and climate-related events. In the Bay Area,

shoreline infrastructure is among the most vulnerable, where it is in the path of sea-level rise and

storm surges. Yet the shoreline is also where some of our most significant public assets, including

our airports, major highways, railroads, and wastewater treatment facilities, are located.

Transportation. Climate change will affect transportation systems at all levels, including planning,

design, construction, operation, and maintenance. Potential economic impacts of climate change

on transportation include: lost worker productivity from delays; impeded and more expensive

movement of goods through ports, airports, and rail systems; and increased costs of repairs and

maintenance of transportation systems. Climate change could also impair the safety of travel.

Several factors contribute to the susceptibility of transportation infrastructure to climate change

impacts, including age, condition, proximity to other infrastructure elements, and current level of

service.

CONCLUSION

Climate change adaptation will need to be dealt with at all levels of government. Yet it is at the

local and regional levels where vulnerability can best be understood and addressed. Although

there is some uncertainty around when we will experience various climate changes, planners can

today anticipate their trajectories and begin thinking ahead about how to prevent catastrophic

impacts.