Noise Pollution Modelling In Dhaka City: A Gis Approach

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NOISE POLLUTION MODELLING IN DHAKA CITY: A GIS APPROACH

Chapter One: An Introduction

Environment is where we live and development is what we do. These words sounds so simple, but the voyage of these two related aspects hasn’t been so simple and nor it will be if men fail to realize the value & importance of environment and the ways of sustainability as well. At present, the world-issues related to environment is growing importance day byday Man’s perception and awareness about environment has gradually been heightened in recent years as he is facing many problems with the environmental changes.

The speed and nature of environmental change (particularly man-induced change) in recent years have brought about a series of environmental problems of global magnitude-including population expansion, energy resources and utilization, the provision of food supplies, exploitation of raw materials, and environmental pollution .So drastic and quick have been the changes that Dasmann has perceived that “the human race is like an ape with a hand-grenade. Nobody can say when he will pull the pin.” (Quoted by park, C.C. 1978).

All natural eco-systems were balanced and unaffected by man until the dawn of the civilization. But the speed and nature of man-induced environmental changes have brought an increasing disharmony between him and the nature at present. Living beings are dependent upon nature for their requirements. Hence the purity and balance of environment is essential. Some of the problems such as- depletion of resources, soil erosion, pollution, deforestation and extinction of wild animals due to increased human population have reached global level.

Man has played a very important part in shaping his environment. He has been responsible for degrading the quality of his environment ever since he appeared on this earth.

1.1 Statement of the problem

In the present age of industrialization and urbanization, noise has become not just an adjust, but permanent part of man’s life. Noise pollution is one of the most harmful pollution. It is an unwanted, unpleasant or disagreeable sound that causes discomfort. Noise is any undesired sound and by extension, noise is any unwanted disturbance within a useful frequency band, for example undesired electrical waves in a transmission or device. Noise is an erratic, intermittent or statistically random oscillation. Since these definitions of noise are not mutually exclusive it is usually necessary to depend upon context for the distinction (Alberti, P .W. 1987).

Noise thus has physical, physiological, and psychological connotations, all of which differ from one another. Physically it is complex sound having little or no periodicity. However, it can be measured and its characteristics analyzed. Physiologically, acoustically and electronically, noise is defined as a signal that bears no information and whose intensity varies randomly in time. Psychologically noise is any sound, irrespective of its waveform, which is unpleasant or unwanted (Alberti, P.W. 1987).

Noise, like any sound is defined in terms of its duration, frequency spectrum (measured in Hz) and intensity measured in sound pressure level (S.P.L) and expressed in decibels (dB). It may be continuous, intermittent, impulsive or explosive. It may be steady- state or fluent.

Harmful sound becomes more pervasive and more intense in urban settings where transport and industrial sources have particularly high nuisance values. Dr. Alan Bell (WHO) has recently pointed out that noise is much more severe than an occupational hazard. It is a public nuisance and danger to mental and physical health. But in the modern age noise is no more an occasional adjusts; it has become permanent part of human life. This harmful sound known as noise becomes more pervasive and more intense in urban settings where transport and industrial sources have particularly high nuisance value. So in present days city dwellers are compelled to face many kinds of harmful effects induced by noise.

In every city of the world, the early morning tranquility is shattered bythe shrill pressure horns of vehicles like trucks, buses, scooters, motor cycles, and the drivers always pressing the horn out of habit than necessity. As the city gradually awakens all kinds of noise pollutants take to the air, traffic pick up. Factories in residential areas start operations. Radios and transistors blare out the AIR milieu. Motor workshops in the midst of localities start dent beating and hammering.

As the day rises, the noise level in the different parts, of the city increases in and around work places and homes. The peak noise levels are reached in the twilight hours as traffic reaches a peak. Political processions add more with it. In offices also there is noise pollution due to clicking of typewriters, bells, ringing telephones, clattering office machines and conversations. They produce tantrums, headaches, fatigue and even nausea. On road we have noise pollution due to growling automobiles, squealing tires, screeching brakes, screaming sirens, blaring telephones and radios, blasting horns, whining jets and pounding jackhammers. Add to these metabolic sounds, loud mouths, and noisy gaits make our environment noisier.

In industrial zones noises associated with manufacturing. Noises are created with many kinds of construction works. Aircraft, due to their increase in size and enormous increase in numbers, have become one of the most troublesome sources of noise pollution. The scream of jet engines is not conductive to tranquility and repose. In some locations, conversations stop every few seconds, television viewing and listening becomes impossible, and sleep and relaxation are interrupted. This condition is multiplied many times throughout the country and the world.

Acute exposure to intense noise may temporarily impair heaving; while repeated occupational exposures to high levels can cause permanent deafness. Increased noise levels are also associated with cardio-vascular, endocrine, respiratory, neurological and psychological changes. Some of which are indicators of increased stress.

Noise pollution is assuming increasing dimensions with increase in the number of vehicles and urbanization in many parts of the world as well as in Bangladesh. In Bangladesh, Dhaka is the most vulnerable place for noise pollution. Because, in Dhaka there is a large number of vehicles, industries, markets, offices, and population with their many kinds of noise making activities.

1.2 Aims & Objectives

Dhaka is becoming a vulnerable place of noise pollution since last two decades. Noise is apparently increasing its dimension with the increases of the number of vehicles, industries and urbanization. Now this has become a permanent part of man’s life. Violent noise can cause many kinds of damages to the human health. As a vulnerable area in terms of noise pollution of Dhaka City, Ganabhaban & adjacent area has been taken as the study area to understand the status and magnitude of noise pollution in an important area. More over parts of this area is full of trees & plants which can have a correlation with mitigating the effects of noise.

The overall study objective was to produce a noise model in Dhaka City using GIS approach, particularly having the study area as Ganabhaban & adjacent region. This would serve as a strategic planning and noise reduction tool.

With a view to achieving this overall objective it is concluded that eventually a noise pollution modelling should:

1. Examine and identify the present level of noise pollution of the different points and important places of the study area providing information of noise pollution level status.

2. Determine the quantity of vulnerable institutions in the different influence zones of noise pollution of the study area.

3. Determine the role of vegetation cover as mitigating agent of noise pollution.

4. Generate isoline maps of noise level of the study area in such a way which would be able to determine the influence zones of pollution and to determine the role of vegetation cover as mitigating agent of noise pollution.

Along with these major objectives, there is an auxiliary objective also, that is to realize the people’s perception about noise pollution.

1.3 Survey of the literature

During the last two or three decades literatures have been accumulated on noise pollution in the context of some developed and conscious countries of the world. In Bangladesh the problem of noise pollution became a considerable issue only very recently. So here in this country there is a lack of literature related to noise pollution. However, noise is gaining importance as a cause of environmental pollution in major cities of the world Dhaka is no exception.

Related to the source of noise pollution, a study was conducted by Zaidi (1989). He found that 55% of noise came from motor vehicles, 20% from construction work and workshop garage and 14% from metal industries. He also found that among motor vehicles, auto-rickshaw ranked first (52%) as a contributor to noise production. In order to save on fuel cost, auto-rickshaw drivers use higher proportion of lubricant to petrol, thus producing the menace of carbon-loaded fumes. Zaidi also found that noise produced by auto-rickshaw ranged between 100-140 dB. Noises that are harmful for health and well being have also encroached on the community. However this kind of problem created by auto-rickshaw has been controlled to some extent by introducing CNG driven auto-rickshaw.

Tripathy (1999) provides a fairly comprehensive treatment of the subject-noise pollution. He mainly focused on the prevailing atmosphere in Indian mines. Yet his descriptions are highly valuable for general readers as well as researchers as those deals with fundamentals of noise, mechanism of hearing, effects of noise on human body and mind, noise measurement and noise survey. He also focused on primary needs of the researchers whose subject area is “Noise Pollution”. To discuss the problem “noise”, he started with some fundamental subjects such as characteristics of sound, pitch, frequency, wavelength, amplitude, loudness, sound pressure, intensity, sound units, definition of noise and noise pollution etc. Tripathy (1999) mentioned many kinds of sources of noise pollution with special reference of source of noise in mines. In this context he gave some important tables of the sources of noise pollution with their sound level value. He classified noise depending on sources of generation, sources in mines, different noise sources, and hearing impairment. He also focused on human hearing mechanism and effect of noise on human health .To describe effects of noise on human health he highlighted the auditory effects like NIHL and some non-auditory effects also. He also mentioned some important noise measuring instruments and their measurement technique, principal and maintenance. Tripathy (1999) discussed the noise survey methods in mines with intense care. Most importantly he mentioned some relevant noise control techniques. He also mentioned noise standards of a few countries.

Sethi, et al, (1991) highlighted noise pollution while discussing environmental pollution. They also focused a few fundamental issues related to noise pollution at their first portion of the paper. They mentioned the nature of sound and noises i.e. pitch, frequency, amplitude, and loudness as fundamental subjects.

They also described some effects of noise pollution on human health and most importantly they provided a table which carries the examples of noise pollution and human response. They also described the kinds and speed of sound as well as sources and abatement of noise.

Srivastava, Y.N. (1995) discussed noise pollution along with other pollution of cities as they are noisy places. Noise pollution imbibes itself a serious threat to the quality of mans environment. In this regard, he has mentioned physical discomforts and damages caused by noise. He has cited some physical responses at different levels of noise.

To describe the health hazards of noise pollution he has noted that noise not only interferes with communications but also affects our peace of mind, health and behavior. Srivastava (1995) has also mentioned the main sources of noise pollution. The most important part of his paper is noise pollution control. He has showed some relevant measure to minimize noise.

Alam, M.S. (1989) has also noted some important measures to control noise, such as emphasizing on producing of low sound creating engine for all kinds of transport. In this regard he has given the example of the technology of U.S. army and navy, as they successfully produced and used low sound creating engines. He also mentioned the usefulness of proper engine covers to control noise and ear plug to protect noise. Alam (I989)) has given a good description about the fundamental subjects of noise and harmful effects of noise pollution. He has also cited what should be the role of government to control noise.

Kudos, V. P. (1990) has given a nice statement of the problem ”Noise pollution”. He described some fundamental issues related to noise pollution and has given a noise figure which shows the various sources of noise pollution and their effect. He has also given two other important tables by which we can get information about threshold of hearing for young healthy ears as a function of frequency response characteristics. He provided some important tables very relevant to this problem .

The tables are bearing information about acceptable noise limits for working areas, estimated community response to noise, Swiss proposal about noise levels, number of fatal accident due to noise in India and noise levels in different cities of the world. He has given some suggestions to control noise pollution. Kudos (1990) cited important information about the effects of noise pollution over human health.

Alberti, P.W. (1987) mainly emphasized on health hazards of noise pollution. First of all, he has given some important definitions of noise in different points of view and also mentioned historical consideration of noise pollution.

He showed the sound stimulation. Alberti, (1987) has given a very large and elaborate description of the effects of noise pollution on human health. He has given a vast statement of all kinds of auditory and non-auditory effects of noise pollution. To describe auditory effects of noise pollution, he cited NIHL, NITTS, NIPTS, Tinnitus, acoustic injury, hair cell injury etc. To give a statement about non-auditory effects he included; illnesses, arousal in adults, sleep difficulties, mental problems induced by noise and many oilier problems. In his paper he mentioned some important things like; infra sound, ultra sound, vibration etc. He has cited some methods of personal protection from noise pollution.

Mer, Y.N. and Bissau, S. (1987) emphasized the effects of noise pollution on human health in their statement. They mentioned auditory and non-auditory effects of noise pollution. They have given some suggestions about remedial measures of noise pollution. Kumar, R (1987) has mentioned the effect of noise pollution on human health in comparison with rural quiet life. He cited that noise pollution poses quit a different problem for urban settings.

Shaha, SK (2000) has given a nice and brief statement of noise pollution problem. He included some important and relevant definition of noise pollution in his essay. He noted some synthesized effects of noise pollution. Paul, N.K. (I999) described the relation between urban health and noise pollution.

He quoted that in a recent study it has been observed that as a result of noise pollution the amount of milk production from cows has been decreased. And it is also observed that noise pollution has ill effects over physical growth of some animal. Islam, B (2000) has given a statement of the severity of noise pollution in urban areas and has given some suggestions too. His essay can be rather considered as a brief general description of noise pollution. Akhter, K.S (1998) mentioned the impact of noise pollution over hearing ability. She quoted a finding of a study which was organized in Britain, that killing instinct can be stimulated by noise pollution and in Britain 5 percent of the homicide per year are occurred due to this reason. Gupta, P (1964) has noted the effects of low frequency sound on human health.

A research work related to the noise pollution of Dhaka City has been accomplished by Chakraborty, M.R. (1999). In his report he has given the sound level data of a few cities. Hasan emphasized in his study on hearing impairment of auto-rickshaw drivers due to noise pollution.

DOE (1997) organized a study to find the status of noise pollution of Dhaka City. They have collected sound level data from 20 important points. In table, they have presented the data quite nicely. They have also provided the highest and the lowest average data in that table. They have also conducted a questionnaire survey and provided the relevant data. They mentioned some remedial measures as well.

Shahnaj, K. (1999) has given her statement about noise pollution as a health hazard. In her discussion she mentioned how noise pollution of Dhaka City affects the city dwellers and in this regard she emphasized on child health. She has quoted some sound level data provided by DOE (1997).

Haider, M.I. (1997) studied the environment of Tangail city. As a part his work he has mentioned the condition of noise pollution of Tangail city. Disaster report of Bangladesh (1998) has given a general description about noise pollution.

Agarwall, S.K. (1991) worked on automobile noise pollution. He mentioned how automobiles act as a source of noise pollution. Andrews, W.A. (1972) has given some ideas for thought and research about noise pollution.

Haq, Mohammad Ahsanul (2000) conducted a study on noise pollution of Dhaka City. He investigated the vulnerability of noise pollution in Ramna Thana as the study area. He generated a noise level contour map which could successfully show the vulnerability in the study area. It was one of the pioneer initiatives of making a noise map using GIS approach. He also examined the ill effects of noise pollution on a number of victims.

Iqbal, Kazi Farhed (2007) investigated the different aspects of noise pollution in Dhaka City. In his study, he emphasized on Dhaka University area mainly. He has successfully presented much information in this context.

Mahadi, Md. (2005) produced a paper on noise pollution in Dhaka City. In his paper he mainly interpreted the study conducted by World Health Organization (in 2002, at 45 points) on noise pollution of Dhaka City. He has also focused on some basic issues in this regard.

According to a study provided by Bangabandhu Seikh Mujib Medical University, hearing ability of Dhaka city dwellers has been reduced in the last 10 years. About 5% to 7% of the patients admitted to University hospital is suffering from noise induced hearing loss (Tanvir Ahmed, et al, 2004). Another study (2007) especially on “Noise induced hearing Loss (NIHL)” in Sahbagh area has been conducted by the Department of Environmental Science of Jahangirnagar University, reported that about 10.3% of the people in this area are suffering from noise induced hearing loss (Rajesh Roy, 2007). And there are evidences of behavioral or psycho-physiological changes among street hawkers in the area. Rahman, Md. Arifur, et al (2008) discussed about noise mapping. They presented the aspects of noise mapping nicely. They conducted the study in Shahbag area.

Some of the above mentioned literatures related to noise pollution of Dhaka city provide useful information in this regard. But those works do not provide enough information about the vulnerability of the different influence zones of noise pollution of Dhaka. Those works didn’t aim at producing a model of noise pollution in Dhaka City at all and at the same time didn’t investigated whether vegetation cover have any mitigating effect on noise pollution any way. This indicates the relevance to research interventions in this context and related issues.

1.4 Relevancy of the work

Noble prizewinner German microbiologist Robert Koch said, “A day will come when man will have to fight merciless noise as the worst enemy of health” .He added more “Noise like smog agent of death” (cited in the report of DOE,’97).

Noise is very harmful for environment at the same time for human health. According to Dr.S.K. Shaha the most dangerous effects of noise pollution on human can be mentioned as follows:

1. It affects human health, comfort and efficiency. It causes hypertension, makes the skin pale, and leads to excessive secretion of adrenaline hormone into blood stream that is responsible for high blood pressure.

2. It causes muscles to contact leading to nervous breakdown, tension and even insanity.

3. It increases rate of heartbeat, digestive spasms and dilation of pupil of eye.

4. It affects health efficiency and behavior. It may cause damage to heart, brain, kidneys, liver and psychological and pathological disorder such as; hypertension, insomnia and emotional stress.

5. Prolonged exposure to high-pitched noise causes hearing loss.

Dr. Alan Bell (WHO) has recently pointed out that noise is much more severe than an occupational hazard. It is a public nuisance and a danger to physical health (Shaha, S.K. 2000). So a serious view of the increasing noise pollution must be taken to assess the correct situation and to take appropriate measures to protect people from hazard of noise.

But in Bangladesh very little attention is paid to control noise and a poor number of research works has been done related to this field. So there is a huge research gap in this particular subject. Dhaka is the most vulnerable place for noise pollution in Bangladesh, because of having a large number of industries, vehicles and inhabitants with their many kinds of tools that can produce noise. For this reason Dhaka should be focused first in case of the discussion of noise pollution.

Most of the literatures related to noise pollution in Bangladesh, tried to focus the present state of noise pollution in Dhaka City and some other cities. And some other literatures in this context tried to determine the effects of noise pollution over human health. However, those are not enough to realize the whole situation of a bigger city like Dhaka. More and more investigations and intensive studies at micro level are required to draw a generalized picture at macro level.

A modelling can be able to add valuable part in this context. Moreover, a modelling of noise pollution using GIS approach would be realistic enough to explore the exact situation and this kind of approach is easily understandable and would be a handy tool for policy makers. A series of modelling at micro levels would be effectively capable of producing a desired generalized picture of the noise pollution of the entire Dhaka City.

Ganabhaban and adjacent region has been chosen as the study area of this research because, it is one of the most important parts of Dhaka City. Important residences, organizations, offices, hospitals, educational institutions, park, etc. are situated here in this area. Moreover, important roads regarding national connectivity are also passes through this area.

Specially, honorable Prime Minister’s residence (Ganabhan) made this area more important. Because of these effective reasons many kinds of activities are being practiced here in this area and many people come here to participate in many types of activities like; administrative tasks, business, jobs, medical support, education, conference, trade expo, travelling etc.

Therefore, a large number of vehicles are seen on the roads for transportation purpose. This situation leads the area to be one of the most vulnerable areas of the city in terms of noise pollution. So, in the view point of the importance and vulnerability of the area it deserves an intensive study. The study results would produce a clearer picture of noise pollution status of this area and would be helpful for the policy makers to deal with the situation as well.

1.5 Methodology

This particular study mainly depended on primary sources of data. Primary data were collected through different processes. The processes were as mentioned below- Sound level data collection.

The sound level data were collected from different points and vulnerable institutions, which were selected according to the importance and vulnerability. Data were collected from different points as well as 25 meter apart from those points (most of the time) to determine variation of the influence of noise and to achieve representative mean value. The data collection process conducted in three-week days along with a holy day in every week over a month. Data collection process continued from 9 a.m. to 8 p.m. in three shifts in each day. To determine the average sound value of the noise pollution, readings were taken repeatedly after certain interval.

The data in every location were taken at three specific times of the day and they are:

? 9am to 11am

? 12pm to 4pm

? 5pm to 8pm

The data were taken in two different days situations:

? Working days data

? Holidays data

Weighting: A-weighted sound levels were measured during the study. The “A weighting” characteristic is simulated as “Human Ear Listening” response.

A location map and a sound level meter were always carried during the data collection. A digital sound level meter was used to record the sound level. The sound level data for different location for different specified time of a day were collected.

The roadside sound level data were taken by standing on the roadside. Any kind of noise barriers, bad weather, were avoided for measuring the actual sound level produced by the vehicles and other sources. Several numbers of readings of sound levels were taken by the sound level meter. All the data were recorded in computer for mapping and analysis.

Noise Measuring Instrument

A portable and digital sound level meter (model-Lutron-SL-4010) has been used to collect the data. The sound level meter is built in the internal “External calibration VR” on the front panel.

Measuring Procedure

1. Sliding the function switch to “1” makes the meter to power on position.

2. Determination of proper measuring range is done by selecting the “Range switch”.

It is done by following the indication of upper & lower range indicator in the left corner of the LCD monitor, which shows the dB range selection is upper or lower setting and indicates the user to slide the “Range switch” to other range for measuring.

3. Holding the instrument in hand and point the microphone at noise source in a horizontal position makes the meter capable of displaying the actual sound level of the source in the LCD monitor on dB unit.

4. During the measurement, the switch on “Hold” position will freeze the displayed value and the switch on “1” position will display the continuous measurement.

5. Strong wind (over 10cm/sec) striking the microphone can cause misreading for measurement in windy locations; a windscreen should be used in front of microphone.

Duration of measurement

The data collection process conducted in three-week days along with a holy day in every week over a month. Data collection process continued from 9 a.m. to 8 p.m. in three shifts in each day. To determine the average sound value of the noise pollution, readings were taken repeatedly after certain interval.

Data Standardization

Several sound level data were taken at each location points and after that, they were averaged to get the final value for sound level. The data was averaged because the sound level of a place varies due to different types of sources such as traffic signal, honking, crowd etc.

Data analysis and presentation

For data analysis and presentation various GIS (Arc view 3.2a and Arc GIS 9.2) software were used. Isoline and surface were generated on the basis of noise level data, which has been collected from the different points and important places of Ganabhaban & adjacent area. Isoline contours were produced at the interval of 3dB. Different colors were used in certain maps to indicate different noise levels. The isoline clearly depicts the spatial variation of noise. The co-ordinate system projection was BTM. For tabular data analysis and presentation MS-Excel software were used.

Questionnaire Data collection

A questionnaire survey was conducted to understand the peoples concern about noise pollution and their physical and mental reaction to noise pollution. The questions were structured in a very straightforward way to get both descriptive and measurable information. Purposive random sampling is followed in performing the questionnaire survey.

1.6 Organization of the study

The various topics in the study correspond approximately with their chronological treatment. Chapter-1, the introductory chapter has been framed to provide statement of the problem, aims and objectives, including a short literature review on noise pollution. This chapter also deals with study methods projecting objectives to be worked with, methodological aspects of data collection, handling and analysis. In addition, various adopted procedures in generation of data are also mentioned.

Environment, environmental pollution and noise pollution related fundamental issues are discussed in chapter-2. This gives a generalized idea of noise pollution its sources and classification. Sound measuring instrument, mechanism of hearing and most importantly effects of noise pollution on human health is also mentioned in this chapter.

Location, socio-economic condition, establishments, institutions, transportation system and residential areas of the study area is discussed in chapter-3. A brief discussion on different species of vegetation covers of the study area has also been mentioned here.

Chapter-4 presents analysis of data, examining the nature and effects of noise pollution in the study area. All kinds of primary data are analyzed and presented here. This chapter gives the information about the state of noise pollution in the study area both in working day and holiday. Ten isoline maps based on noise levels (of different aspects) are produced in this chapter to generate an overall model of noise pollution. Two other maps showing the different levels of noise (of different days) in bar diagrams are also presented to clarify the condition of fluctuations. The role of vegetation as mitigating agent of noise pollution has been discussed and analyzed in this chapter. State of noise pollution in hospitals and schools is also included. In addition, people’s opinion about different aspects of noise pollution is presented here.

Chapter-5 provides a sum-up of the study including research findings, problems and future research.

Chapter-3

Ganabhaban and adjacent region is the study area of this research, it is one of the most important parts of Dhaka City. Important residences, organizations, offices, hospitals, educational institutions, park, etc. are situated here in this area. Adjacent major roads are playing important part in national connectivity. Specially, honorable Prime Minister’s residence (Ganabhan) made this area more important. As a result, many kinds of activities are being practiced here in this area and many people come here to participate in many types of activities like; administrative tasks, business, jobs, medical support, education, conference, trade expo, travelling etc. Consequently, a large number of vehicles are seen on the roads for transportation purpose. This situation leads the area to be one of the most vulnerable areas of the city in terms of noise pollution. So, in the view point of the importance and vulnerability of the area it deserves an intensive study and the results would produce a clearer picture of noise pollution situation of this area and would be handy for the policy makers to deal with the situation as well.

3.1 Location

Ganabhaban & adjacent area situated in the ward number 40 of Dhaka City Corporation. The study area is mainly part of Agargaon & Sher-e-Banglanagar area that is mid-northern part of Dhaka City. The location can be clearly viewed from the study area map(Map-1: The Study Area).

3.2 Socio-economic Condition

Most of the people are engaged with tertiary economic activities. Government service holder, private service holder, doctors, teachers, military personnel, many types of businessman, nurses & medical personnel, hawkers and rickshaw-pullers do their activities here.

3.3 The Establishments and Institutions

The establishments and institutions are mentioned below-

Ganabhaban (Honorable PM’s residence)

Ganabhaban is the official residence of the Honorable Prime Minister of Bangladesh. It was constructed as a part of National Assembly Complex. The decision to construct National Assembly Complex at Dhaka was originally taken in 1959 (Banglapedia).

Louis I Kahn, one of the greatest architects of the time, was initially selected for designing the National Assembly complex. He was not commissioned out-right but was asked to present preliminary ideas for the complex and in March 1962 he was formally commissioned for the job. A sprawling area of 208 acres of land to the north of present Manik Mia Avenue was acquired in 1961 for the project of the second capital and the master plan was ready in 1962. The construction started in 1964 with an initial estimated cost of about $15 million (Banglapedia).

The construction of the complex along with all services and facilities was completed in 1982 at a revised cost of $32 million. The complex includes the National Assembly Building, hostels for members of parliament, ministers and secretaries, hospitality halls and community buildings all linked by roads and walkways and surrounded by attractive gardens and lakes.

The changes in the original master plan mainly involved location of Supreme Court, a Grand Mosque and the President’s Palace. Efforts were made to make the palace as inconspicuous as possible and these were moved away from the axis of the assembly building. The president’s palace (to-day’s Ganabhaban, the official residence of the Prime Minister), was one of the first structures to be built. The design of the Assembly building was completed in 1964. Construction work started immediately. The main structure was under construction at the time of the liberation war in 1971, when all work stopped. In 1974 the government of Bangladesh took the creditable decision of completing the building without any change.

Bangabandhu International Conference Centre (BICC)

Bangladesh’s only international convention center, theBangabandhu International Conference Center (BICC) has always surpassed everyone’s expectations by bringing the highest number of interactions while conducting notable events, conferences, seminars, corporate shows, product launches and meetings. The Conference Center provides specialized services and is known for its outstanding infrastructure and its team of experts who are always committed towards ensuring the smooth running of every event. Well equipped with the latest high-tech facilities and conveniences, the BICC also provides a splendid hall for exposition purposes of national and international significance. There is provision of parking facilities for both visitors and organizers as well as other exhibitor related services and conveniences.

Figure-2: BICC

The Election Commission

The Election Commission is an independent constitutional body in the exercise of its functions and subject only to the Constitution and any other law. The Commission may authorize its Chairman or any of its members or any of its officers to exercise and perform all or any of its powers and functions under the law. Article 126 of the Constitution and Articles 4 and 5 of the Representation of the People Order, 1972 provide that it shall be the duty of all executive authorities to assist the Election Commission in the discharge of its functions. The Commission has the power to require any person or authority to perform such functions or render such assistance for the purpose of electron as it may direct.

Ministry of Defence (MoD)

Ministry of Defence (MoD) situated in Ganabhaban Complex, just to north-east of Ganabhaban.

Hospitals

Shahid Shohrawardi Hospital, one of the largest governmental hospitals and medical colleges of Dhaka is situated on Mirpur road.

National Institute of Cardiovascular Diseases & Hospital (NICVDH), Sher-e-Bangla Nagar, Dhaka, is also a large governmental hospital.

Educational Institutions

Sher-e-Bangla Agricultural University

Sher-e-Bangla Agricultural University is the most ancient agricultural university in Bangladesh, situated in Sher-e-Bangla Nagar. It was established as BAI on December 11, 1938 by Sher-e-Bangla A.K. Fazlul Huq, the Chief Minister of undivided Bengal. At that time the name of this institution was “The Bengal Agricultural Institute”. Later it becomes “East Pakistan Agricultural Institute” and on the emergence of Bangladesh as independent country in 1971, the name of this institute was spontaneously changed to Bangladesh agricultural Institute (BAI).

Since its inception the BAI had functioning as “faculty of Agriculture” under Dhaka University, the BAI-affiliated College till it’s up gradation to Sher-e-Bangla Agricultural University in 2001. On 22 June 2009, a bill was placed in the parliament to assign the President as chancellor replacing the Prime Minister.

Ganabhaban Govt. School

Ganabhaban Govt. School is a secondary school which is situated to the north of Ganabhaban Complex.

3.4 Roads and Transport System

Adjacent major roads of the study area are Mirpur road, Rokea sharani and Bijay sharani (partially).Crescent lake is also an important road of this area. Major roads are connected by narrower roads like front side road of International Trade Field. Adjacent major roads play important part in national connectivity. Consequently, a large number of vehicles are seen on the roads for transportation purpose. This situation leads the area to be one of the most vulnerable areas of the city in terms of noise pollution.

Figure-3: Roads and Transport System

3.5 Residences and Quarters

The most important residence is Ganabhaban, which has been mentioned earlier. There is a considerable number of Government quarters are situated here, among them there are superior type of quarters for respectable persons, E-type quarters for high officials and other type of quarters can be mentioned.

3.6 Park

Chandrima Uddyan is one of the nicest parks of Dhaka City, which situated in the study area. The park is full of green trees; most of them are exotic type. Trees of different types have the ability to mitigate the ill effects of pollution. Relevantly it can be said that trees act as a barrier in the path of sound/noise waves and consequently reduces the ill effects. In this view point this part of the study area considered with much importance. Trees of this park are discussed separately in this report.

The whole Chandrima Uddyan is made magnificent by animating the adjacent Crescent Lake with light and fountains and development of adjacent panoramic views. It takes a different look when the mirrored and transparent floor of the hanging bridge on the lake radiates gentle radiance during nighttime.

The last end the garden has a two-storey structure constructed on the 24,000 cft area. A room for prayers is housed on the first floor while library, archive, museum and seminar hall are on the ground floor. The grave of former President Ziaur Rahman is situated at the centre of the park.

Figure-4 : Chandrima Uddyan

3.7 Vegetation Cover of the Study Area

There are different types of trees and plants in the study area. Exotic types of trees are dominant in number but there are also local varieties. Different types of trees of the study area are discussed below-

Polyalthia longifolia (Devdaru / var-pendula)

It is a lofty evergreen tree, native to India, commonly planted due to its effectiveness in alleviating noise pollution. It exhibits symmetrical pyramidal growth with willowy weeping pendulous branches and long narrow lanceolate leaves with undulate margins. The tree is known to grow over 30 ft in height.

One might mistake it as a tree with effectively without branches, but in fact an Ashoka allowed to grow naturally (without trimming the branches out for decorative reasons) grows into a normal large tree with plenty of shade. The two look identical in every way, trunk and leaves and bark and flowers, and it is perfectly obvious the straight ramrod versions are specially created much as the trimmed trees along lake Geneva are in another shape.

Figure-5:Polyalthia longifolia (Devdaru / var-pendula)

Samanea saman (Rain tree)

Rain tree (Samanea saman) is easily recognized by its characteristic umbrella-shaped canopy. When grown in the open, the tree usually reaches 15–25 m (50–80 ft) in height with a canopy diameter wider than the tree is tall. Rain tree is most important in the Pacific as a shade tree on small farms, along roads, in parks and pastures.

The wood has limited use for carved bowls in local markets; it could be developed more widely as a commercial timber, comparing favorably to black walnut. A multitude of minor uses is documented for rain tree, most of them of purely local significance, but all could be explored for wider applicability. Rain tree naturalizes freely almost everywhere it has been introduced and is considered an invasive pest in Vanuatu and Fiji.

Mesua Nagassarium (Nageswar)

It is a tall tree reaching up to 100 feet tall, often buttressed at the base with a trunk up to 2 meters in diameter. It is common in wet zone at Sri Lanka up to 1500 meters. It has simple, narrow, oblong, dark green leaves 7–15 cm long, with a whitish underside; the emerging young leaves are red to yellowish pink and drooping. The flowers are 4–7.5 cm diameter, with four white petals and a center of numerous yellow stamens.

Albizia Chinensis (Chakua Koroi/ Albizia)

Albizia chinensis is an unarmed, deciduous or evergreen tree with a flat, spreading crown, up to 30(-43) m tall and trunk up to 70(-140) cm in diameter. Bark is dark gray, rather smooth, densely hooped, thin; and live bark is 5 mm thick & pinkish-red. Branchlets are slightly angular in the distal parts. Leaves are bipinnate; stipules and auriculate.

Peltophorum pterocarpum (Radhachura / Yellow Flamboyant)

It is a deciduous tree growing to 15–25 m (rarely up to 50 m) tall, with a trunk diameter of up to 1 m. The leaves are bipinnate, 30-60 cm long, with 16-20 pinnae, each pinna with 20-40 oval leaflets 8-25 mm long and 4-10 mm broad. The flowers are yellow, 2.5-4 cm diameter, produced in large compound racemes up to 20 cm long. Peltophorum pterocarpum is widely grown in tropical regions as an ornamental tree, particularly in India, Bangladesh, Nigeria, Pakistan, and Florida and Hawaii in the United States. The wood has a wide variety of uses, and the foliage is used as a fodder crop.

Figure-6:Peltophorum pterocarpum (Radhachura / Yellow Flamboyant)

Delonix regia (Krishna chura/ Red Flamboyant)

It is a deciduous tree growing to 15–25 m (rarely up to 50 m) tall, with a trunk diameter of up to 1 m. The leaves are bipinnate, 30-60 cm long, with 16-20 pinnae, each pinna with 20-40 oval leaflets 8-25 mm long and 4-10 mm broad. The flowers are red, 2.5-4 cm diameter, produced in large compound racemes up to 20 cm long.Itis widely grown in tropical regions as an ornamental tree, particularly in India, Bangladesh, Nigeria and Pakistan.

Figure-7:Delonix regia ( Krishna chura/ Red Flamboyant)

Tectona grandis (Sagon/ Teak)

A large to very large deciduous tree having height up to 35 meters; bark having brown or grey color and shallow longitudinal furrows; Leaves simple, opposite, broadly elliptical or obovate, acute or acuminate, coriaceous, possessing minute glandular dots; Flowers white, many, small, having pleasant smell, in large erect terminal branched tomentose cymose bladder like calyx; seeds usually 1-3, ovate, marble white. Sagon is a well known for its high grade timber. Wood is used for ship building, railways, piles in harbour, bridge-building, construction work, furniture and cabinet work.

Carallia brachiata (Matan/Carallia)

Tree usually grows along freshwater streams with obovate, opposite leaves to 16 x 8.5 cm, has scattered dark glands present on the lower leaf surface. Stipules 10 –15 (-25) cm long. It has flowers with 7 green to cream petals. Fruit of this tree is a berry 7-10 mm wide, orange to black, 1-seeded.

Callistemon linearis (Bottle brush)

This evergreen shrub or small tree gets its species name citrinus from the lemony smelling oil glands present in the olive green, lance-shaped leaves. Springs to summer flowers are terminal, axillary, and crimson colored. Plant in neutral to acid, moderately fertile soil in full sun. This plant is tough and makes and excellent hedge. C. linearis has narrower leaves.

Acacia auriculiformis (Acacia)

This plant is raised as an ornamental plant, as a shade tree and it is also raised on plantations for fuel-wood throughout south-east Asia, Oceana and in Sudan. Its wood is good for making paper, furniture and tools. It contains tannin useful in animal hide tanning. In India, its wood and charcoal are widely used for fuel. Gum from the tree is sold commercially, but it is said not to be as useful as gum arabic. The tree is used to make an analgesic by indigenous Australians. Extracts of Acacia auriculiformis heartwood inhibit fungi that attack wood.

Figure-8:Acacia auriculiformis (Acacia)

Gliricidia sepium (Gliricidia)

Gliricidia sepium is a medium-sized tree and can grow to from 10 to 12 meters high. The bark is smooth and its color can range from a whitish gray to deep red-brown. It has composite leaves that can be 30 cm long. Each leaf is composed of leaflets that are about 2 to 7 cm long and 1 to 3 cm wide. The flowers are located on the end of branches that has no leaves.

These flowers have a bright pink to lilac color that is tinged with white. A pale yellow spot is usually at the flower’s base. The tree’s fruit is a pod which is about 10 to 15 cm in length. It is green when unripe and becomes yellow-brown when it reaches maturity.

Figure-9:Gliricidia sepium (Gliricidia)

Casuarina littoria (Jhau)

It is an ornamental exotic plant and has been brought here from Australia. It is tall tree with narrow leaves.

Artocarpus heterophyllus (jackfruit)

The jackfruit is a species of tree in the mulberry family (Moraceae), which is native to parts of Southern and Southeast Asia. It is the national fruit of Bangladesh. It is well suited to tropical lowlands. Its fruit is the largest tree borne fruit in the world, reaching 80 pounds (36 kg) in weight and up to 36 inches (90 cm) long and 20 inches (50 cm) in diameter.

Mangifera indica (Mango)

Mangifera indica is a species of Mango in the Anacardiaceae family. It is found in the wild in Southern Asia and cultivated varieties have been introduced to other warm regions of the world. The species appears to have been domesticated about 4,000 years ago. The species was first moved around 400-500 BC from northeastern India to east Asia; next, in the 15th century to the Philippines; and then, in the 16th century to Africa and Brazil by the Portuguese. The species was described for science by Linnaeus in 1753.

Cocos nucifera (Coconut)

The coconut (Cocos nucifera) is an important member of the family Arecaceae (palm family). It is the only accepted species in the genus Cocos, and is a large palm, growing up to 30 m tall, with pinnate leaves 4–6 m long, and pinnae 60–90 cm long; old leaves break away cleanly, leaving the trunk smooth. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word. The coconut palm is grown throughout the tropics for decoration, as well as for its many culinary and non-culinary uses; virtually every part of the coconut palm can be utilized by humans in some manner.

Aegle marmelos (Bel tree)

The bel tree of the family Rutaceae, found wild or cultivated throughout India. The trees bear strong spines; alternate, compound leaves, each with three leaflets; and panicles of sweet-scented white flowers. The tree is valued for its fruit, which is oblong to pyriform in shape and 50–250 mm (2–10 inches) in diameter. The fruit has a gray or yellow rind and a sweet, thick, orange-colored pulp. The unripe fruit, sliced and sun dried, is traditionally used as a remedy for <href=”#toc=toc9031677″ title=”dysentery;”>dysentery.

#.The tree species are determined with the cooperation of Mr. A N M Rubaiat, Asst.

Professor, Dept. of Botany, Islamic University, Mr. Mohammad Hossain Ali, Officer, Ministry

of Defence and Mr. Shahjahan Ali, Scientific Officer, SPARSO.

Chapter 4

Introduction

This section presents the overall state of noise pollution and its influences & effects over the study area. An effort has also been made here to analyze and present the role of vegetation covers as mitigating agent of noise pollution. The data of this chapter were collected from primary sources. Sound level data were collected by sound level meter to determine the state of noise pollution of the study area.

Secondly, a questionnaire survey was conducted to understand the people’s perception about noise pollution. All kinds of data are analyzed and presented in this chapter.

4.1 The State of Noise Pollution in the Study Area

Ganabhaban and adjacent region is the study area of this research, it is one of the most important parts of Dhaka City. Important residences, organizations, offices, hospitals, educational institutions, park, etc. are situated here in this area. Adjacent major roads are playing important part in national connectivity. Specially, honorable Prime Minister’s residence (Ganabhan) made this area more important. As a result, many kinds of activities are being practiced here in this area and many people come here to participate in many types of activities like; administrative tasks, business, jobs, medical support, education, conference, trade expo, travelling etc. Consequently, a large number of vehicles are seen on the roads for transportation purpose. This situation leads the area to be one of the most vulnerable areas of the city in terms of noise pollution. State of noise pollution of the study area is discussed below from different views.

Table-3: Highest & Lowest Average Value of Noise Level in Working Day

PlacesPoints Working Day(9am-8pm)
Highest Average Value(dB-A) Lowest Average Value(dB-A)
1 Front of PM’s residence 84.5 71.6
2 Mirpur Road 83.6 72.3
3 Hospital –NICVDH (Front side) 79 72.6
4 Shohrawardi Medical Coll. &Hospital(Front Side) 82 71.6
5 MoD Mosque 71 56.6
6 Front of MoD 74.6 62.6
7 Govt. Quarters (Ganabhaban Area) 70.6 54
8 Ganabhaban Govt. School (Front side) 76 63
9 Sher-e-Bangla Agri. University (Front side) 68 57
10 Agargaon Police Box 78.3 63.6