Land Surface Temperature and Its Association with Built-Up and Green Cover

“

Urban areas are growing at a rapid rate due to the increasing demand for residential, commercial and industrial purposes. Population growth and industrialization have further acted as a catalyst in the urban in-migration process. In 1950, 30% of the world’s population was living in the urban areas which increased to 54% in 2014 and it is expected to increase to 66% by 2050. This trend is more rapid in less urbanized world. In 1991, the urban population of India was 217 million which increased to 377 million in 2011.As per the United Nations report, the urban population of India will increase by nearly 500 million between 2010 and 2050 (United Nations 2012). The rapid increase in urban population, urbanization and expansion of urban land leads to the increase in the built-up area and decrease in the green cover in the cities that provides several ecological services. Urbanization results in the conversion of green belts of cities into the built-up area and the agriculture land which is mainly in the periphery of the cities into the built-up area. It is also seen that the change in land use/cover leads to loss of agricultural lands, loss of forest lands, increase of barren areas, an increase of impermeable surface cover because of the built-up area, etc. With these physical changes mainly decrease in green cover and increase in the built-up area, the land surface temperature (LST) is most likely to increase. In all cities, the green area is a basic need because it contributes to a healthy city environment as well as healthy living and satisfies public aesthetics and most importantly keeps land surface temperature significantly low. Among all physical components, green space is an important component of the physical environment and it has multi-dimensional functions; it helps in enhancing air quality, conservation of biodiversity and reduction of the urban heat island (UHI) effect and it is also an indicator of ecological sustainability. Reduction of the green cover and increase in the built-up area (impervious surface) contribute to the increase of phenomena of urban heat island (UHI) in the cities which leads to the deterioration of the quality of environment in the urban area. Therefore, based on the above consideration with added dimension of climate change, the present study aims to analyze the association between built-up, green cover and land surface temperature in Delhi. It is expected that results of the analysis will help town planners in adopting planning measures to make cities livable and prevent diseases which result from exposure to heat.

”