Here is your essay on Climate and Urban Planning

In the field of urban planning, the important role of urban climatology cannot be overemphasized. The construction and design of new buildings demand that the full consideration should be given to the relationship between climate and architecture.

Besides, the field of urban climatology is mainly concerned with planning to reduce urban thermal excesses and air pollution.

The application of climatology to urban planning begins with the selection of an urban centre. Along with this the urban planner must take into account the timing and effects of urbanization on the various weather elements.

However, there are several restraints imposed on the successful application of the principles of urban climatology in designing and planning a city.

However, attempts should be made to analyse the stages by which the principles of urban climatology may be conveniently introduced to the decision-making processes. The aforesaid principles must combine the socio-economic and other factors to obtain the optimum climatic environment.

In order to cope with the problem of air pollution and the thermal stresses, certain remedial measures have been suggested. The most effective means of reducing the urban temperature excess is, indeed, the properly spaced green areas in the city.

It has been suggested that well- thought out plans of the vegetation areas in cities would go a long way in improving the ventilation and circulatory systems thereof. Thus such vegetation areas or parks will prove helpful to keep under control the noise levels and also the air pollutants.

Such vegetation areas may also be used as recreation areas. A careful selection of the building materials of different compositions and of different colours will have their effects on albedo and heat absorption.

Thus they are able to create temperature differences within the city which in turn encourage mixing and ventilation. Similarly water bodies in the vicinity of a city may help to minimise the effect of maximum temperature. Besides, these water bodies may have aesthetic and recreation appeal.

Since there is a huge concentration of people and their economic activities in relatively smaller areas, it provides opportunity to look into the matter of cultural modifications of climate. One of the most important factors is the greater densities of atmospheric pollutants over cities.

However, there are other factors such as surface materials, surface shapes, and heat and moisture sources which make the urban areas different from the rural areas, because they affect radiation, visibility, temperature, wind, humidity, cloudiness and precipitation etc.

Concentration of pollutants in the atmosphere above a city produces urban aerosols. These aerosols have their own effects on several climatic elements in the city. For example, in winter and at high latitudes the aerosols reduce the intensity of insolation in the cities.

The aerosols are in greater concentrations when there is stability in the lower layers of the atmosphere and there is calm. The urban aerosols are selective because they reduce the proportion of ultraviolet radiation more than the long wave radiation. They also adversely affect the bright sunshine hours and reduce horizontal visibility.

Because of the concentration of aerosols over the cities, the diurnal ranges of temperature are less over there than in the countryside. In addition, the nighttime inversions over the urban settlements are weaker. To the leeward side of the cities the rural inversions tend to intensify.

The impact of air pollution can be minimised by avoiding sitting pollution sources in more congested areas or in areas prone to frequent low inversions. Large chimneys which are high penetrate the inversion layer. These high chimneys should be built, as far as possible, downwind from residential and business districts.

The roughness of the city surface tends to intensify the frictional drag which produces turbulence. The mean wind speed within the city is lower than in the nearly rural areas.

The city should lie in a liner orientation across the direction of prevailing winds. The development planning of a rapidly growing city makes the application of climatology and meteorology more relevant.