Urban heat islands are the areas in which the temperature is so high at the night as compared to the day. The term urban heat or heat islands are used for both areas which are populated or nonpopulated but the surrounding area must be temperate the urban heat island mostly occurs during the winter season and the summer season.
Causes of urban heat islands
There are many causes of the urban heat islands, some causes of the urban heat islands are as under
The main cause of the urban heat island is the human activities in the urban areas is the human activities disturb nature day by day by constructing buildings construct the roads of cement so by these activities the urban area heat should be enhanced so in urban areas the roads constructed by the sufficient amount of the cement and the sidewalks.
The footpath should construct by using the asphalt so the cement absorbs the heat are the radiations so by this the temperature is the heat should increase in the urban areas as compared to the surrounding rural or the undeveloped areas of that city
The second main cause of the urban heat islands is the less vegetation or the less green coverage as we know the plants are the environmental buffers the plants occur the process of the extra transpiration
The transpiration so in evaporation, the water evaporates from the soil, plants tops and the transpiration is the process in which the water vapors should form the stomata of the plant into the surrounding area is the environment so in the urban areas due to development the plants and green vegetation are cut due to this the green vegetation are reduced.
Due to this the Co2 which is also known as the greenhouse gas so due to less vegetation the absorption of the Co2 is decreased and due to this the heat doesn’t absorb and the temperature of the area should be increased
The overpopulation is the big cause of the urban heat islands due to overpopulation the vegetation should be removed and construct the buildings for the living purposes and due to this in less area build a very huge and many buildings so due to this sun rays should be reflected and absorbed due to this the heat increased in the urban places as compared to the rural areas
Effects of urban heat islands
The urban heat islands affect the animals, weather and it also affects the human health severely the detail of the effects of the urban heat islands are as under
The effect of urban heat island on the weather
The urban heat islands not only increase the temperature of that area it should also influence are affect the weather condition of that area and due to this the precipitation level, cloud level, fog formation, humidity level, and wind patterns of that area is affected due to the hot temperature the wind move upward due to this the 20 to 40 miles city are affected and the precipitation is also greater at 28 percent up to the city center
Effect of urban heat island on animals
The urban heat island affects the animal’s life terribly. Due to the heat islands the animal’s habitats and the colonies are affected for example the colonize of ants, common house geckos, and grey-headed flying fox recently the grey-headed flying fox move to Melbourne Australia due to increasing temperature or the heat in the city limits.
Due to heat increase, the winter climate is the same as the animal’s habitat the heat islands also affect the food and water supply for the animals for example due to the heat the buildings are so hot when the rainfall occurs the water runoff from the hot buildings and then the hot water runs off in streams and lakes.
Due to this the temperature of the streams and the lakes are increased at the 20 to 30 degree Fahrenheit it cause the thermal pollution it affects the fishes in streams lakes due to heat in the urban city the plants should be affected and due to this the food supply for the animals are also affected some animals depend on the plants for diet purposes and the animals match their breeding season to the plants growing season so due to the heat is increased in temperature the plants growing season should be extended so due to this, the breeding of the animals are also affected
Heat islands effects on human health
The urban heat islands not only affect the weather and the wildlife of that area it should also affect the human health of that area the temperature increased very severely during the summer season mostly the senior citizens are affected due to the severe heat for example in the U.S the 1000 people average are died due to the extreme or temperature the inhabitants of heat islands also suffer due to the extreme heat.
Because in heat islands the temperature of the night are also extreme as compare to the rural areas the extreme heat also escort some cramps for example heat stroke, heat cramps, heat exhaustion during the heatstroke the respiratory disturbance, immobility, or decreased responsiveness heat exposure also causes due to the extreme heat and due to the heat exposure the death is also occur
Control of urban heat islands
The hazards of the heat islands are controlled by the different methods some methods discussed are as under
Use of light-colored concrete and white roofs
The light color reflects the sunlight as compared to the dark light so for the construction of roofs the light color concrete should be used so by this, the sunlight rays are reflected and the heat islands are reduced
Green roofs and vegetation cover
The green plants play a vital role to reduce the urban heat islands the green roofs are the cover vegetation cool the surrounding environment by the process of the transpiration or the evaporation so due to these processes the water vapors are occurred in the wind and the air cool down and the heat islands should be reduced the plants are also cool the air by absorbing the Co2 Green Roof
Planting trees in urban cities
Planting trees in the cities also decreased the urban heat islands because the plants are produced the fresh air by absorbing the Co2 it should also release the oxygen and produce the cooling effects the deciduous plants are more important because it causes cooling during the summer seasons and didn’t block the warm air during the winter
Implementation and sensitization of heat reduction policies and rules
The rules are followed by the state to clean air use the renewable sources and also less use the things which are responsible for the emission of the greenhouse gases and by this, the reduction in the global warming and the urban heat islands are reduced aware of the people for the hazards of the urban heat islands and also aware the people for the benefits of the Green belts and the eco-roofing
Dr. Muhammad Khalid Mukhtar (Ph.D.)
University of Sargodha, Sargodha