Ten disasters in Shanghai;

typhoon

The city is hit by tropical cyclones in the Pacific Ocean every year. 1949-2002, there were 186 tropical cyclones passing within 550 kilometers of Shanghai, which affected Shanghai and brought disasters such as strong winds, heavy rains and storm surges.

Two rainstorms

The annual average rainfall is 1 123mm, of which 70% is concentrated in April-September. Because of the low terrain, rivers are easy to flood and fields are easy to be flooded. Urban drainage capacity is unevenly distributed and needs to be further strengthened.

Three storm surges

Storm surge disasters caused by typhoons often occur in coastal areas along the Yangtze River in Shanghai, causing serious damage to seawalls, dams, inland flood control walls and other projects.

Four tornadoes

There are 2-3 times a year on average, mainly in suburbs (counties), which is sudden, destructive and harmful.

Five red tides

There are many large-scale red tide disasters (the area exceeds 1000 square kilometers) in the waters near the Yangtze River estuary every year. It has caused serious damage to marine living resources, and the toxicity of red tide organisms threatens human health and life safety.

Six dense fog

Surrounded by rivers and seas, Shanghai is full of moisture. Due to the influence of urban heat island effect and atmospheric environment, foggy weather tends to increase, mainly in spring and winter, which has a great impact on urban water bodies, roads and air traffic.

Seven high temperatures

The days of high temperature above 35℃ in Shanghai are generally about 9 days, and can reach 20 to 30 days when it is abnormal, which has a certain impact on urban water supply, power supply, agricultural production and citizens' life.

Eight lightning strikes

Shanghai is a lightning-prone area in China, with an average annual thunderstorm day of 53.9 days. Casualties caused by lightning strike occur every year, and the severity of economic losses is also on the rise.

Geology

The main threats are land subsidence and groundwater pollution. After taking comprehensive control measures such as artificial recharge, the settlement is controlled; However, the groundwater pollution area is still more than 2 100 square kilometers, and shallow aquifer pollution is more common.

Ten earthquakes

The geological structure of Shanghai where moderate and strong earthquakes are likely to occur has recorded earthquakes of magnitude 5 or so in history. The possible ripple effect of earthquakes in the South Yellow Sea and surrounding provinces and cities on Shanghai can not be ignored. Now it is listed as a key earthquake monitoring and defense area by the state.

Why are there so few natural disasters in Shanghai?

1. Considering from seismology, Shanghai is not in the collision zone of China plate, so the possibility of earthquake is very small.

Considering the climate, the average annual temperature in Shanghai is not high in China, and the average annual rainfall and snowfall are very few.

3. Considering the geographical environment and location, there are fewer mountains, more plains and less debris flow in the area under its jurisdiction; There are few rivers and the probability of flooding is small. Only one Huangpu River can still be tossed around. The mouth of the Yangtze River is relatively wide, and the basic energy will be quickly integrated into the sea, which will not cause floods.

Of course, it's hard to say when special circumstances happen. Hehe, I believe that understanding science is our most correct understanding of disasters.

However, the main man-made disasters in Shanghai include road traffic accidents, fires, chemical accidents and "lifeline engineering" accidents. It is understood that there are more than one million motor vehicles in Shanghai, and the total length of roads exceeds 6,500 kilometers. Road traffic accidents are the types of accidents with the highest incidence, the largest number of casualties and the largest economic losses in Shanghai, and they are on the rise. Fire is also common and harmful. In the process of production, storage, transportation and use in Shanghai, more than 7,570 kinds of harmful chemicals are involved, and the annual consumption exceeds 654.38 billion tons, which easily leads to chemical accidents. Local aging of existing underground pipelines for gas and tap water and power supply communication lines in Shanghai, combined with illegal construction and man-made destruction, gas leakage and explosion, bursting of large-diameter water pipes and interruption of power supply communication lines occur from time to time.