This map comes from the Major natural disaster Atlas of China in 2010 Surveying and Mapping Press and China Map Publishing House. The editing unit is the National Natural Resources and Geospatial Basic Information Database Project Office.

The direct dangers of floods in disasters: flooding of rivers, flash floods, urban water accumulation, internal flooding, waterlogging, destroying crops, buildings, and materials, causing casualties, diseases, crop failures or harvests, and traffic and communications are blocked. Secondary hazards: agricultural and forestry disasters (pest and disease), geological disasters (debris flow, landslides, soil erosion), hydrological disasters (floods, guilts).

Wind disaster: It is a serious meteorological disaster that is windy enough to endanger production activities, economic construction, and daily life. China is a country that is more affected and severely affected by wind disasters. In the winter and spring seasons, the northerly winds that go south with the outbreak of cold air reach 7 to 8 levels. Inner Mongolia, Northeast China, Hebei, northern Henan, northwestern Shaanxi, and northwestern Shanxi are all areas where winds often occur. In the summer, strong convective weather systems often produce gale storms. On the coast, strong winds often occur in the Yellow Sea, the Bohai Sea and the East China Sea. Wind disasters mainly include: strong winds, tornadoes and dry hot winds.

Snow disaster: Snow disaster is also called white disaster. It is a natural phenomenon caused by snow accumulation in a large area due to long-term heavy snowfall. It is a kind of animal weather disaster that often occurs in Chinese pastoral areas. There are three main types of snow disasters: First, snow accumulation. Due to excessive snowfall, vegetable greenhouses and houses are crushed, bamboo and fruit trees, power transmission and communication lines are cut off; roads are buried by snow, transportation, Both aviation and people’s travel have been greatly affected. In the pastoral area, the winter grassland has more than 20 cm of snow, and the flocks have difficulty eating; the snow is more than 30 cm, and it is difficult for horses and cattle to eat. Therefore, in pastoral areas, because of excessive snowfall and excessive snow, coupled with persistent low temperatures, the snow layer is maintained for a long time, causing the pastures to be buried in snow, livestock can not be eaten or fed, and they are hungry or infected, and even a large number of deaths.

Second, the wind blows snow. A lot of snow is rolled up by the strong wind and runs with the wind. It is impossible to determine whether there is snowfall at that time, the level of visibility is low, the pedestrians are lost, the traffic is interrupted, the pastures are flooded, and the herds are blown away or injured.

Typhoon refers to tropical cyclones formed on the vast sea surface above 26 °C in the tropical or subtropical zone. The World Meteorological Organization defines: Tropical cyclones with continuous wind speeds in the 12th to 13th grades (ie 32.7m to 41.4m per second) are typhoons or hurricanes. The western North Pacific (north of the equator, west of the international date line and east of 100 degrees east) is often referred to as the typhoon, while the North Atlantic and East Pacific regions are commonly referred to as hurricanes. Every summer and autumn season, there are many violent storms called typhoons on the northwestern Pacific Ocean adjacent to China. Some of them are scattered on the sea, while others are on the land, causing storms and rains. It is a kind of natural disaster.

Cold air is the main cause of low temperature freezing disasters. In the spring and autumn, the cold air in the north and the warm and humid air in the south frequently meet, often causing low temperature and rainy weather. The strong cold air, especially the outbreak of the cold wave, makes the temperature drop sharply, which will cause disasters such as “cold spring” and frost.There is a process of accumulation, strengthening, southward movement and outbreakof cold air, and there is a corresponding weather situation. Under the intense radiant cooling, large-scale cold air masses will form in the Arctic Ocean and Siberia, and adiabatic expansion and cooling will occur due to the rising motion of the air in the cold reactor, and the cold air reactor will continue to increase. When the cold air pile reaches a certain intensity, it will erupt southward under a favorable circulation situation, and a cold wave will occur.