The Civil Analyst

  Haphazard development in urban areas has led to undesirable changes in the landscape. The areas which were once open land or covered with vegetation have been converted into concrete forests, asphalt covered roads, sidewalks and other infrastructure. The urbanization leads to the formation of Urban Heat Islands (UHIs) - the phenomenon referring to warmer temperature in the city relative to outlying rural areas. According to the Environment Protection Agency , bigger cities in US have air temperature up to 5ºC more than the nearby natural land cover. UHIs effects are most intense during the clear sky and calm winds as heavy cloud cover prevents solar radiation to reach earth surface, reducing day time warming in cities and strong winds accelerate atmospheric mixing, decreasing urban rural temperature gradient. How does it form? There are various factors that contribute to the formation of UHIs but the significant causes of UHIs formation are urban developments by changing in...

  Three oxygen atoms when bound together forms ozone (O 3 ). It is very unstable and highly reactive relative to oxygen and often used as a bleach, a deodorizing agent, and a sterilization agent for air and drinking water. Ozone can be ‘good’ or bad for health and the environment depending on the place of its occurrence. Stratospheric ozone( at an altitude of 25-30 Km) is good because where it is found naturally and acts as a protective radiation shield for living organisms on earth. It strongly absorbs ultraviolet light in the region 220-330 nm and thereby protects life on earth from severe radiation damage. Ozone found in tropospheric region is termed as bad ozone or ground level ozone. When nitrogen oxides (NO x ), volatile organic compound (VOCs) (emitted by cars, power plants, refineries, chemical plants etc.) and sunlight reacts together to form various secondary pollutants, which are also known as photochemical oxidants. One of the most abundant photochemical oxidants is oz...