Characteristics of Climate Change in Dongguan
With the rapid development of social economy and the rapid expansion of city scale in Dongguan, the surface properties of Dongguan have changed. A large number of cement, asphalt pavements and various building walls have effectively absorbed a large amount of solar radiation, and the surface water content has also decreased. With the increase of population, factories and vehicles in Dongguan, more and more fuels are burned, and there are more and more dust in the air, which is also very beneficial to absorb the energy of thermal radiation in the environment. Dongguan's urban heat island effect has been presented, mainly as follows:
1. The average temperature rises.
It can be seen from the curve of average temperature change over the years that before the 1980s, the annual average temperature in Dongguan changed slowly, but after the 1980s, the temperature showed an obvious upward trend, and it was warmer in 18 years, especially after the 1990s. Since the historical record began with 1957, 19 appeared after 1987 in the 20 years with the highest annual average temperature. The average temperature in 2002 was as high as 23.6℃, the highest in history.
2. Decrease of relative humidity
The average relative humidity decreased from 76.5% in 1959 ~ 1985 to 73.6% in 1986 ~ 2006, with a decrease of 2.9 percentage points, and the largest decline occurred after the mid-1980s. The maximum annual average relative humidity is 80%, appearing in 1959, and the minimum is 7 1%, appearing in 1995.
3. The sunshine time is reduced.
The annual average sunshine hours decreased from 1963 ~ 1 hour in 0969 to1hour in 2006, a decrease of 25 1 hour. The maximum annual sunshine hours is 2320.8 hours, appearing in 1963, and the minimum is 1558. 1 hour, appearing in 1997.
4. Decline in visibility
It can be seen from the average visibility curve over the years that the visibility was almost above 18km before 1980s, but after 1980s, the visibility dropped rapidly, and the average visibility in 2006 dropped to 9.3km, which was the lowest in the past years.
The Impact of Climate Change on Dongguan
1. Extreme abnormal weather increased.
Under the background of global warming, the extreme abnormal weather in Dongguan has increased. Dongguan has been warm in winter for 20 consecutive years, and the high temperature (above 35℃) weather has also increased significantly, and the phenomenon of "autumn tiger" is obvious. The increase of heavy precipitation and thunderstorms has caused more and more social and economic losses. The smog is getting worse and worse, and the visibility is reduced.
1. 1 Dongguan has experienced warm winters for 20 consecutive years.
From the curve of the average temperature change in winter (65438+February-February) over the years, it can be seen that before the mid-1980s, the temperature in winter changed gently, and after the mid-1980s, the temperature in winter showed an obvious upward trend, and the city has had a warm winter for 20 consecutive years.
In addition to warm winter, the high temperature (above 35℃) weather in our city has also increased significantly. It can be seen from the curve of high temperature days over the years that before the mid-1980s, the annual high temperature days were generally below 10. Since the mid-1980s, the number of high-temperature days has increased sharply, and the number of high-temperature days in 16 years is greater than 10 days, all of which occurred after 1986.
The phenomenon of "autumn tiger" in our city is becoming more and more obvious. Since 1980s, the average temperature has been increasing year by year from 10 to1(autumn), and the average temperature has exceeded 23℃ in nine years, all after 1990.
1.2. With the increase of heavy rainfall and thunderstorms, the social and economic losses are increasing.
The data analysis in recent years shows that the increase of heavy precipitation and thunderstorms in Dongguan has caused more and more social and economic losses. On May 25th, 2005, a local rainstorm occurred in Guancheng area, with the rainfall of 109.3mm from 03: 00 to 04: 00, which set a new record of 1 hour rainfall since the meteorological record in Dongguan, causing serious waterlogging in some places. From July 14 to July 17, 2006, there was a persistent rainstorm in our city. The maximum daily rainfall recorded by Shilong automatic weather station reached 399.6 mm, the second highest on record. The economic loss caused by the rainstorm exceeded 10 billion yuan, and the waterlogging in Hanxi River was serious. The increase of high temperature weather leads to the increase of thunderstorm intensity, and serious thunderstorm events occur frequently, which leads to lightning strikes on some buildings and electronic equipment, causing great economic losses, and people are killed by lightning every year.
On May 2, 2006, there was a rainstorm in our city. A truck in front of Liaobu Square was flooded in the tunnel, and only the roof was exposed.
1.3. The smog is getting worse and worse.
With the expansion of city scale, the rapid development of industry, the increase of population and cars, urban pollution is further aggravated, and the number of smog days in Dongguan is obviously increasing.
In the 33 years from 1957 to 1989, there were only 12 days of haze, but in the 1990s, the number of haze days reached 25 days. After entering 2003, the number of haze days increased sharply, and in 2003 and the following years it was 12 1 day. With the increasingly serious smog phenomenon, the visibility of our city is declining year by year. By 2006, the average visibility was only 9.3 kilometers, the lowest in history.
2. The factors affecting weather and climate are more complicated.
The factors affecting weather and climate are very complicated, which are caused by the interaction of various factors in the integrated system of atmosphere, hydrosphere, cryosphere, lithosphere and biosphere. Because human activities emit a lot of greenhouse gases, the factors affecting weather and climate are more complicated, and abnormal weather disasters occur frequently. Take the weather and climate in Dongguan in recent years as an example: continuous drought in autumn, winter and spring occurred in 2004-2005, which is rare in recent years; The rainfall in 2006 reached 24 12.4 mm, which was the wettest year on record. In the first ten days of September, 2006, there were four heavy rains in our city, including three heavy rains with a total rainfall of 506.6 mm, which was the largest in the same period in history. In June, 2006, the number of thunderstorm days reached as many as 4 days in 5438+065438+ 10, which was the highest in the same period in history. The prediction of these small probability events is a difficult point in current scientific theory and technology.
3. Impact of climate change on social economy
The impact of climate change is gradual, but irreversible. Although it is not as direct as the damage caused by a disastrous weather process, it has brought unbearable and lasting serious impact on the natural ecosystem and social economy. At present, the climate monitoring system in our city is under construction, and the research on the interaction between climate change and various industries needs to be strengthened. From the monitoring data at home and abroad and the evaluation and analysis of our existing data, it is preliminarily shown that climate warming leads to sea level rise, climate zone moving northward, species distribution change, increased pests and diseases, and continuous generation of new viruses. At the same time, climate warming has also caused frequent disasters, increased droughts and floods, intensified cold and warm weather and worse weather, which directly affects social security, human health and economic development, including transportation, environment, sanitation, energy and water resources.
3. Impact of1.on traffic
Traffic is affected by meteorological conditions such as rainstorm, thunderstorm, strong wind, haze, fog and high temperature. If the rainstorm makes the ground slip and accumulate water, it will cross the subgrade, resulting in low visibility and easy to cause traffic accidents. According to British statistics, there are 25% more traffic accidents in rainy and snowy weather than in sunny days. Of the 6.8 million traffic accidents in the United States every year, 20% occur in bad weather conditions such as rain, snow or ice. The high temperature in summer leads to the increase of road surface temperature, and it is also easy to cause the puncture of motor vehicle tires, which leads to the accident of car crash and death. Heavy fog affects the visual range, and it is also easy to cause traffic accidents. Take Dongguan as an example. From July 14 to July 17, 2006, there was continuous rainstorm in our city, and the eastern expressway was flooded, which led to traffic disruption. Especially with the length, density, vehicle growth rate and quantity of high-grade highways in our city jumping to the forefront of the province, traffic meteorological safety has become an increasingly important work.
3.2. Impact on environmental health
Climate warming has intensified the spread of infectious diseases by insects, and the incidence of malignant infectious diseases such as malaria, scarlet fever, jaundice and encephalitis has increased. Most importantly, climate change will inevitably lead to the extinction of some old species, and at the same time, it will inevitably produce new species. The change of species may break the existing pattern of viruses, bacteria, parasites and allergens, produce new varieties, bring another danger, and may activate a new virus. A research report of the World Health Organization confirms that at least 30 new infectious diseases have appeared in the past 20 years. In the process of human activities, new viruses will be discovered continuously in the future, posing a serious threat to human health. The outbreak of SARS virus in 2003 is the best example.
Haze weather increases, and harmful particles in the air also increase, which can directly or induce respiratory diseases and gastrointestinal diseases, and breed various viruses and bacteria. The decrease of sunshine increases rickets, which has a direct impact on people's health.
3.3. Impact on energy and water resources
Climate warming leads to the increase of extreme abnormal weather such as high temperature, drought, strong wind and rainstorm, which further increases the energy consumption required by social and economic development and residents' life, and the contradiction between power supply, oil supply and water supply is more prominent.
In recent years, with the rapid development of social economy, Dongguan's annual electricity consumption has been ranked first in Guangdong Province, and the power supply form is very tight. According to the survey, the peak of electricity consumption in our city generally appears in June, July and August, and the electricity consumption is the least in February. Generally, in late June, our city began to be controlled by subtropical high pressure, and the hot weather increased, and the electricity consumption gradually increased.
Climate warming has further increased energy consumption and fuel consumption of automobiles. The shortage of automobile oil in recent years is an example.
With the increase of high temperature weather, the water demand of cities has further increased. According to statistics, the per capita water resources in Dongguan City is only 322 cubic meters, which is not only lower than the international water shortage line of per capita 1.750 cubic meters, but also lower than the serious water shortage line of 500 cubic meters, which is also far from the per capita water resources of 2,594 cubic meters in Guangdong Province. With the rapid development of social economy and the acceleration of urbanization, the water supply situation in Dongguan is still grim.
Dongguan is rich in air water resources. If the annual precipitation is 1770 mm, the water resources obtained from the air will reach nearly 4.4 billion cubic meters every year, which is equivalent to a large reservoir. How to use some facilities to guide the collection, treatment and utilization of rainwater is also an initiative with ecological and economic benefits.
3.4. Impact on urban planning and construction
In the process of building an ecological green city in Dongguan, urban planning and meteorology are inseparable. First of all, the urban heat island effect causes the temperature to rise, while waterscape and greening can effectively reduce the temperature. Therefore, urban planning and construction should fully consider the green area, that is, analyze the impact of urban development and atmospheric environment. Secondly, the planning of urban functional areas and the analysis of environmental suitability, such as what is the dominant wind direction of the city, and the pollution industry is not suitable for planning on the windward side; If the wind speed in a certain area is relatively high, it will be conducive to the spread of pollution and more suitable for industrial development zones. Thirdly, can urban construction adapt to the impact of climate change and bad weather, such as the impact of more and more heavy rainfall on urban roads and flood drainage systems, and the impact of strong thunderstorms on electronic equipment and high-rise buildings.
3.5. Impact on the insurance industry
The influence of climate on insurance is mainly concentrated in the flood season from April to September, which is generally caused by lightning strikes, strong winds, typhoons, rainstorms and sudden landslides caused by rainstorms. With the frequent occurrence of severe weather such as rainstorm, strong thunderstorm and smog, especially in some weather-sensitive industries, the risks of the insurance industry have also increased. According to the statistics of Ping An Insurance Company and PICC P&C Insurance Company, in 2006, the compensation for property losses was mainly caused by rainstorm, especially the rainstorm of 7. 16. Only this rainstorm, Ping An Insurance paid10 million yuan. In 2006, 265,438+00 people went to the Meteorological Bureau to issue meteorological certificates for insurance claims.
3.6. Impact on agriculture and forestry
Climate warming will also have a direct or indirect impact on planting and aquaculture in Dongguan. For example, the reduction of sunshine can slow down the growth of crops; Heavy rain caused floods, which seriously affected crops and flooded fish ponds; High temperature advances flowering period and increases agricultural pests and diseases. Take litchi and banana for example, long-term low temperature, high temperature, rain, fog and acid rain are very unfavorable to their growth.