What are the factors that affect the temperature?

First, the influence of the characteristics of urban underlying surface (the interface between the bottom of the atmosphere and the surface)

A large number of artificial structures in the city, such as paving the ground and various building walls, have changed the thermal properties of the underlying surface. Urban surface water content is less, and more heat enters the air in the form of sensible heat, which leads to air warming. At the same time, the absorption rate of sunlight on the urban surface is higher than that on the natural surface, which can absorb more solar radiation, so that the air can get more heat and the temperature will rise. For example, in summer, the lawn temperature is 32℃, the canopy temperature is 30℃, the cement floor temperature can reach 57℃, and the asphalt pavement temperature can reach 63℃. These high-temperature objects form a huge heat source, baking the surrounding atmosphere and our living environment. How can they not be spicy?

Second, urban air pollution.

Motor vehicles, industrial production and a large number of people's activities in cities produce a lot of nitrogen oxides, carbon dioxide, dust and so on, which can absorb a lot of energy from the thermal radiation in the environment, produce a well-known greenhouse effect, and cause further warming of the atmosphere.

Third, the influence of artificial heat source.

Factories, motor vehicles, residents' lives, etc. Burning all kinds of fuels consumes a lot of energy. Countless stoves are burning, emitting heat!

Fourth, the natural underlying surface of the city is reduced.

Buildings, squares, roads, etc. It has increased a lot in the city, and the natural factors such as green space and water body have decreased accordingly, releasing more heat and absorbing less heat, and the ability to alleviate the heat island effect has weakened.

Because the increase of artificial structures and the decrease of natural underlying surface are the main reasons of urban heat island effect, increasing the proportion of natural underlying surface in cities through various channels is one of the effective ways to alleviate urban heat island effect.

Urban green space is the main natural factor of the city, and vigorously developing urban greening is the key measure to reduce the influence of heat island. Green space can absorb solar radiation, and most of the absorbed radiation energy is used for transpiration and heat consumption of plants and converted into chemical energy in photosynthesis, so the heat used to raise the environmental temperature is greatly reduced. Garden plants in the green space constantly absorb heat from the environment through transpiration, reducing the temperature of the surrounding air. Every hectare of green space can absorb 8 1.8 MJ of heat from the surrounding environment every day, which is equivalent to the cooling effect of 189 air conditioner. Garden plants can absorb carbon dioxide in the air through photosynthesis. One hectare of green space can absorb 1.8 tons of carbon dioxide on average every day, which weakens the greenhouse effect. In addition, garden plants can retain dust in the air, and each hectare of green space can retain 2.2 tons of dust every year, which reduces the dust content in the ambient atmosphere by about 50% and further inhibits the rise of atmospheric temperature.

The results show that the urban green coverage rate is inversely proportional to the intensity of heat island. The higher the green coverage rate, the lower the intensity of heat island. When the coverage rate is greater than 30%, the heat island effect is obviously weakened. When the coverage rate is more than 50%, the reduction effect of green space on heat island is extremely obvious. The concentrated green space with a scale of more than 3 hectares and a green coverage rate of more than 60% is basically equivalent to the temperature of the natural underlying surface in the suburbs, that is, the heat island phenomenon is eliminated, and a low-temperature zone centered on green space is formed in the city, which has become an excellent environment for people's outdoor recreation activities.

In addition to green space can effectively alleviate the urban heat island effect, water surface and wind are also effective factors to alleviate the urban heat island. The heat capacity of water is large, and the temperature rise is the smallest under the condition of absorbing the same heat, which shows that the temperature is lower than other underlying surfaces; Evaporation and heat absorption on water surface can also reduce the temperature of water body. Wind energy takes away the heat of the city and can also alleviate the urban heat island to some extent. Therefore, in the planning of urban buildings, it is necessary to combine the local wind direction, not to build all buildings in the east-west direction, but to build a model that is convenient for air circulation; At the same time, it is best to tear down the high school walls of some units and build walls to increase air circulation.

At the same time, reducing man-made heat release, changing civil coal into liquefied gas and natural gas as much as possible, and central heating are also important countermeasures.

Option b is obviously wrong.