Sabtu, 11 Juni 2011

TRANSPORT AND THE ENVIRONMENT

       Over recent years there has been a great deal of concern with the effects of transport on the environment. The  environment may be defined as those conditions under which living organisms exist.
       In man`s environment he needs a number of basic requirements to exist such as air, light, water, warmth, etc and at various times  these factors may be affected to some degree by man`s exploitation of the environment in the provision of industry.
       Man has a responsibility to his environment which must temper other considerations towards development of economic and social ideals. This responsibility needs recognition in ensuring that any changes made to the environment do not cause deleterious effects to mankind as a whole.
       In earlier chapters reference has been made to the need for transport in the economic, social and political development of countries. The aims to achieve these ends may well be associated with a reduction of natural conditions to such an extent that extreme discomfort or lack of well-being occurs. The factors involved here may be broadly classified as follows:-
(a) Water pollution.
(b) Air pollution.
(c) Noise pollution.       
(d) Land use.     
(e) Solid waste.
       These factors may apply singularly or in combination when considering the various types and forms of transport available.
(a) Water Pollution       
       Water is the basic and universal medium in which life reactions occur. It exhibits several qualities that make it espescially favourable to the support of life. The use of water as a purifier is well known, however as the oxygen levels are reduced in water by contaminants its natural value is very much diminished.       
       Although water pollution is generally associated with the discharge of chemicals or other refuse from manufacturing concerns, water transport may well add to this problem by the indisciminate or accidental discharge of fuel and oils or other waste into waterways.
       Port authorities in recent years have placed a greater emphasis in the controlling of such discharges and legislation has been introduced prohibiting discharge of waste in navigable waters. When discharge does occur, investigations are carried out by the authorities, and legal action may be taken against the offenders.
(b) Air Pollution
       The air which living things need for survival, most essentially needs to be free from as many impurities as possible. In the production of energy, waste emissions are discharged into the atmosphere. This is commonly known as air pollution.
       Transport is responsible for emitting about 19 per cent of the carbon dioxide, 64 per cent of carbon monoxide, 39 per cent of oxides of nitrogen and 52 per cent of  hydrocarbons added to the environment. The addition of carbon dioxide reduces the reradiation of  heat away from the earth. It has been estimated that by the year 2000 that extensive flooding may occur due to the melting of the ice cap, if steps are not taken to reduce the carbon dioxide emissions. The solution to this problem appears to be in a change away from fossil-fuel power plants.
       The effect of oxides of nitrogen and sulphur have been found to effect health and that the ability of persons to perform normal physical activities is impaired when breathing oxides from the air. In addition the emission of oxides creates smog which affects visibility in the atmosphere. Although these emissions cannot be completely eliminated in using present fuels, considerable control of the quantity emitted can be exercised. New techniques in motive power design and legislation restricting the amount of pollutants emitted from vehicles are important steps in this regard.
(c) Noise Pollution
       The incidence of noise can affect man`s behaviour or permanently damage his hearing. Because of this, noise control has become a technology of considerable significance. Transport in various forms has long been an offender in producing undesirable noise in the environment. In particular rail, road and air vehicles have been major offenders.
       A considerable amount of research has been performed in this field in the production of motive power that is quieter in operation or by means of installing sound absorbing material on panels to reduce the emission levels. Legislation has also been introduced to contain noise within certain restricted areas or limit the operation of motive power during certain periods of the day.
(d) Land Use
       Land has a wide variety of alternate uses, including industrial, residential and transport uses. There may be a number of natural characteristics of that land which need to be foregone if the land is to be used for any one of these purposes. Although man should not be denied altering his environment according to his needs and develop it, this needs to be done in a balanced manner with minimum effect to flora and fauna.
       In the development of transport, the placement of the way, e.g. roads and railway lines, and terminals e.g. goods yards and airports, may sometimes encroach onto land more suitable for other purposes. The construction of  freeways in urban  areas has been criticized by many people because invariably this has required the resumption of residential and park land. The location of airports adjacent to residential areas causes inconvenience to people living in the area.
       The selection of  routes for road  and  rail construction needs special considerations in relation to environmental changes. These are:-
  1. Where possible they should be constructed on less valuable land and if in urban areas, older properties are usually less valuable than newer ones and may be approaching the need for redevelopment.
  2. Parks and reserves are usually attractive sites and should be avoided as a general rule.
  3. Natural or historical features such as aboriginal carvings and historic buildings should be avoided.
  4. Some areas may be improved by use of  land unsuitable for other types of use.
  5. Routes can be made more attractive by the strategic placement of  trees, shrubs and natural stone and rock settings included as part of  the development.
  6. Care needs to be exercised in the construction to prevent light glare from vehicles disturbing residents at night.
  7. Curves are preferable to straight routes over crests. The curves avoid the broken horizon effect.
       For terminal locations there are a number of considerations that need to be taken into account such as:-
  1. The site should be relatively clear of residential areas to avoid disturbance to residents, particularly at night.
  2. Provision should be made for attractive surroundings including landscaping as part of the project.
  3. The site should be of such size to enable all operations to be performed in the terminal area, so that the need for parking  vehicles in adjacent streets is not necessary and that noise is contained within the terminal area.
  4. Adequate access to the terminal, needs to be available to avoid traffic  congestion.
       Governments are becoming increasingly aware of  the need  to plan land use and  to preserve certain existing features. Special committees have been formed in many cases to study patterns of development and to decide on the appropriateness of  land  being used for  particular purposes.
(e) Solid Waste
        The incidence of  littering and the problems of disposal of solid waste materials is a problem for most societies. Because transport is involved in the carriage of  goods in a packed state, there is a large quantity of disposable packing materials used which needs to be disposed of at varying intervals, while motorists are quite often blamed for  the high incidence of  littering that occurs on roads.
       The disposal of  waste materials  has been alleviated in more recent times by the creation of waste disposal specialist  organizations with facilities to compact waste materials to a size many times smaller than the original space consumed by the waste materials.
      Legislation has been introduced, providing for heavy penalties for littering to ease this problem. 

By:- 
Leslie A. Schumer O.B.E, Hon. F.C.I.T., F.A.S.A., Elements Of  Transport, Butterworths, 1974
Third Edition (Revised) By :-
R.E. Delaney, F.C.I.T.  and  G.W. Woellner, F.C.I.T.

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