Summary of Snow Disasters
What is snow disaster?
Snow disaster is a natural phenomenon caused by a large amount of snow
for a long time. It is a kind of animal husbandry meteorological disasters
that often occur in pastoral areas of China ,mainly refers to the livestock
farming areas which depend on natural grassland grazing, because of the excessive
snowfall and snow cover in winter half year, the snow layer lasts for a long
time, which affects the normal grazing activities of animal husbandry. Snow
disaster is also called white disaster.
Snow disaster mainly occurs in stable snow areas and unstable snow mountain
areas, occasionally in instantaneous snow areas.Snow disaster in pastoral
areas of China mainly occur in grasslands of Inner Mongolia, northwest China
and parts of the Qinghai-Tibet Plateau.
Types and indicators of snow disaster
(1) Types of snow cover
Snow disaster is caused by snow, according to the stability of snow cover,
snow cover in China can be divided into five types:
Permanent snow accumulation above the snow line is greater than that of melting
in the same year, and the snow does not melt all the year round.
The spatial distribution of stable snow cover (continuous snow cover) and the
time of snow cover (more than 60 days) are relatively continuous seasonal snow cover.
Although unstable snow cover (discontinuous snow cover) falls every year, and the
temperature is low, the snow cover is discontinuous in space, mostly in patchy
distribution, the days of snow cover are 10 to 60 days in time, and intermittent.
Instantaneous snow cover mainly occurs in South and Southwest China, where the
average temperature is relatively high,however, in the year when the monsoon is
particularly strong, large-scale snowfall occurs due to cold wave or strong cold
air invasion, but it melts quickly, resulting in short-term (usually no more than
10 days) snow cover on the surface.
There is no snow except for some mountains at high altitudes, no snow has fallen
for many years.
(2) Index of snow disaster
Snow disaster mainly occurs in stable snow areas and unstable snow mountain areas,
occasionally in instantaneous snow areas.People usually use the depth of snow cover
on grasslands as the first sign of snow disaster.Because of the difference of
grassland and the growth height of grass, the snow cover depth of snow disaster is different.
According to the analysis of observation and investigation data in Inner Mongolia and
Xinjiang, the relationship between snowfall and the formation of snow disasters over
the years is compared, and the indicators of snow disaster are as follows:the snowfall
amount of light snow disaster in winter and spring is equal to more than 120% of the
snowfall amount in the same period of the year;the snowfall in winter and spring is
equal to more than 140% of the snowfall in the same period of the year;heavy snowfall
in winter and spring is equivalent to more than 160% of the annual snowfall in the same period.
Snow disaster indicators can also be expressed by other physical quantities, such as
snow depth, density, temperature, etc., however, the greatest advantage of these indicators
is that they are easy to use and the data are easy to obtain.
(3) Classification of snow disaster
According to the formation conditions, distribution range and manifestation of snow
disaster in China, snow disaster can be divided into three types:
Avalanches, snowdrift disasters (snowdrift) and snow disaster in pastoral areas.
According to the climatic law of snow disaster, it can be divided into two types:
sudden type and persistent type.
(1) Sudden snowstorm occurs during or after a snowstorm, and keeps a relatively
thick snow cover for several days, which poses a threat to livestock. This type
is common in late autumn and spring with changeable climate.
(2) The snow cover thickness of the sustained snow disaster to endanger livestock
gradually increases with the snowfall weather, the density increases gradually,
and the stable snow cover lasts a long time. This type can last from the end of
autumn to the next spring.
Of course, snow cover can play a positive defensive role in the overwintering
heat preservation of forage grass, snow melting in dry season can increase soil
moisture and promote the green growth of forage grass.
Snow is also the main source of water shortage or water-free winter and spring
grassland, which can solve the drinking water problem of human and livestock.But
too much and deep snow and too long duration make it difficult for livestock to
graze, even unable to graze, thus forming a snow disaster.
Harm of snow disaster
The hazards of snow disaster are mainly as follows: causing casualties; destroying
houses; destroying biodiversity, causing casualties of animals and plants, such
as piglets and other livestock are also prone to death from frostbite;destroying
or affecting lifeline projects such as transportation, communication and transmission
lines, there have been large-scale blackouts caused by heavy snow in North China.
A large amount of snow can collapse the greenhouse, causing frost damage to vegetables,
snow can also shield room temperature and greenhouse light, which has a greater impact
on vegetable production; snow often accompanied by strong wind cooling, temperature
drops sharply after snow, if preventive measures are not taken in time, often resulting
in low temperature freezing damage.
Snow disasters mainly occur in Inner Mongolia grassland, northwest China and parts
of the Qinghai-Tibet Plateau.At the turn of winter and spring from 1992 to 1993,
heavy snow fell successively in parts of Inner Mongolia, Qinghai, Tibet and Gansu
provinces and autonomous regions, affecting more than 300 million mu of grasslands,
1.1 million people and 1 million livestock.
Frozen rain and snow in southern China since January 10, 2008 is a very rare snow
disaster. 22 provinces (regions and cities) such as Zhejiang, Jiangsu, Anhui, Jiangxi,
Henan, Hubei, Hunan, Guangdong, Guangxi, Chongqing, Sichuan, Guizhou, Yunnan, Shaanxi,
Gansu, Qinghai, Ningxia and Xinjiang have been affected by low temperature, snow and
129 people died in the snow disaster, 4 people were missing, 1.66 million people were
relocated in emergency; 217 million mu of crops were damaged and 3076 mu of no harvest;
nearly 340 million mu of forests were damaged; 485,000 houses collapsed and 168,600
houses damaged, with direct economic losses reaching 151.65 billion yuan.
It is worth mentioning that the 2008 snow disaster is still fresh in the memory of
all Chinese people. Many people may never forget the snow in their lifetime;Shaoguan
Section of Beijing-Zhuhai Expressway was closed and the ice and snow disaster was
serious;Guiyang reproduced the miracle of ice falls;Passengers were blocked for ten
days and ten nights in Lechang, Hunan and Shaoguan respectively by the snowstorm
by bus......Near the Spring Festival, snowstorms suddenly fell in most parts of the
middle and lower reaches of the Yangtze River, and large snowflakes covered the
land in the south.The transmission tower was crushed by ice accumulated on the
brackets, power supply in many cities was interrupted and the city was dark.Water pipes
in disaster-stricken cities were frozen due to low temperatures, people were seriously
short of water for daily use,only could rely on fire trucks to transport drinking water
for residents.Expressways, railways and airports were covered with thick ice, and all
kinds of vehicles could not operate normally, at the peak of spring transportation, a
large number of passengers who were ready to go home for the Spring Festival were stranded
at stations and airports.
The dangerous climate of the ice and snow had nearly collapsed tens of millions of
private car owners and those who were preparing to drive and return home by car;
high-speed road accidents, traffic jams, vehicle damage......
The arrival of this snow disaster was mainly due to the abnormal large-scale
snowfall and severe cold climate in some areas under the background of global
warming.This heavy snow, which has not been seen for 50 years, has caused great
disasters in the southern part of China with great losses to the social economy
and people's lives and property.
Response measures of snow disaster
Warning signals of blizzard
Warning signals of blizzard are divided into four levels, which are blue, yellow,
orange and red, respectively. Shown in table 6-6.
Prevention measures of blizzard
Patrol roads and repair them in time.When blizzard weather occurs, departments such as
transportation, railway, power and communications should strengthen patrols and close
icy roads when necessary, once snow breaks down roads, railways or lines are found,
timely repairs are ensured.
Keep warm and skid-proof when go out.Facing blizzard weather, pedestrians should
pay attention to cold and skid resistance, choose shoes with good skid resistance
when going on the road, and not wear shoes with high heels or hard plastic soles;
when vehicles go out, necessary anti-skid measures should be taken to install
anti-skid chains for the vehicle.
Blizzard raging with reinforcement and protection.Before or during the blizzard,
the temporary structures concerned should be reinforced and protected in time to
avoid being crushed by snow or even causing casualties.
(1) Measures to deal with blizzard disasters
Heavy snow disasters occur almost every year in our country, which often lead to
the isolation of people and animals from the outside world, and suffer disasters
due to cold and hunger, so we should take preventive and emergency measures.
①Preparatory measures for preventing blizzard disasters.Before winter comes,
we should prepare enough food, feed, fuel and clothing;reinforced housing;familiar
with living environment and setting good landmarks;prepare call signals, snow
supplies and medicines;keep warm, avoid frostbite, don't touch cold objects;wear
snow-blind glasses when going out.
Prepare a snow shovel, flashlight and battery-operated radio at home or in the car;
store emergency water and perishable food;close the outside tap to avoid bursting
and flooding;put the special medicine and medical method manual in your room where
you can easily get it;buy a kerosene lamp or heater that can be safely used indoors;
store some salt, hay and sand;make the house population unobstructed.
Fill your car with gas in case you need to drive to a warmer place and check the
car's antifreeze again.
② Physical energy accumulation during blizzard.When a blizzard occurs, you should
stay indoors and try to keep yourself warm.Don't shovel snow, trolley, or try to
walk long distances in the snow, excessive sweating can make you cold or hypothermia
in extreme cold conditions.For the elderly or susceptible, sudden exertion can damage
the heart.Eat more high-energy foods, such as oats, dried fruits, bread and peanut
butter, and plenty of hot drinks to maintain body temperature and fluid intake.
(2) How to deal with the sudden blizzard?
①Stay indoors as much as possible and don't go out.
②If you are outdoors, stay away from billboards,temporary structures and old
trees to avoid damage.When passing under bridges, eaves and other places, careful
observation or bypass should be made to avoid injuries caused by melting ice.
③Non-motor vehicles should give tires a small amount of deflation to increase
the friction between tires and road surface.
④Obey the traffic police's command and traffic guidance arrangements.
⑤Attention should be paid to listening to weather forecast and traffic
information so as to avoid delays due to the suspension or closure of airports,
expressways and ferry terminals.
⑥Drive slowly and keep a distance from the front car.Vehicles should slow down
before turning to avoid braking. Conditions to install anti-skid chains, wear sunglasses.
⑦After the occurrence of traffic accidents, clear signs should be set at the rear
of the scene to prevent the occurrence of serial crashes.
⑧ If there is a power failure accident, the power department should report it
to the power department in time for prompt treatment.
(3) How to deal with snow disaster?
①Attention should be paid to cold and warmth preservation, old, weak, sick and
young people should not go out.
②Don't wear hard or smooth soles when you walk.,cyclists can properly ventilate tires.
③Close doors and windows and fasten outdoor structures.
④ Should evacuate quickly in case of a snowstorm if in a dilapidated house.
⑤Households using stoves for heating should be on guard against gas poisoning.
(4) Prevent livestock from frostbite.
①Keep fat by feeding intensive materials to livestock.
②Clean up the feces in the fence in time, change and sun the mattress
frequently, and keep the house clean and warm.
③Prevent cold wind from entering human and livestock houses.