Causes of floods and hazards, effective preventive measures

The hazards of flood disasters

Refer to the phenomenon of flooding and waterlogging in low-lying areas due to heavy rain, torrential rain or continuous rainfall. Rain and waterlogging mainly harm the growth of crops, causing crop yield reduction or failure, and disrupting the normal development of agricultural production and other industries.

Rainlogging is mainly caused by heavy rain and heavy rain, so it is often closely related to flood disasters. The conceptual difference between the two is that flood disasters refer to disasters caused by heavy rains, torrents or overflowing rivers and lakes; rainwater logging refers to disasters caused by waterlogging and submersion. Rain and waterlogging mainly harm the growth of crops, causing crop yield reduction or failure; floods not only harm crops, but also damage houses, buildings, water conservancy facilities, transportation facilities, electric power facilities, etc., and cause varying degrees of casualties. Since floods and rainstorms often occur simultaneously or continuously in the same area, it is often difficult to accurately define the difference when conducting disaster surveys, statistics, and analysis. In this case, they are collectively referred to as flood disasters.

Distribution of flood disasters

On a global scale, flood disasters mainly occur in areas with multiple typhoons and rainstorms. These areas mainly include: northern Bangladesh and coastal areas; southeastern coastal areas of China; Japan and Southeast Asian countries; the Caribbean and the coastal areas of the eastern United States. In addition, floods are also prone to occur in the inland river basins of some countries.

The dangers of floods

Among various natural disasters, floods are the most common and the most harmful. Floods occur frequently, affect a wide range of areas, are fierce and extremely destructive. The floods not only submerged houses and people, causing a large number of casualties, but also swept away all items in the settlements, including food, and flooded farmland, destroying crops, leading to a significant reduction in food production and causing famine. Floods can also damage factories, communications and transportation facilities, causing damage to the Ministry of National Economy.

Since the beginning of this century, there have been nearly 40 catastrophic flood disasters in various countries around the world, each resulting in the death of tens of thousands of people and the displacement of millions of people. In recent decades, the frequency of floods and disaster losses have increased year by year.

China has been a country prone to serious flood disasters since ancient times. According to incomplete statistics, in the 2155 years from 206 BC to 1949, there were 1,092 major floods in Japan, and floods that killed more than 10,000 people occurred every 5-6 years. This situation has not been fundamentally eliminated in modern times. changes.

Flood disasters not only directly cause casualties and property losses, but also cause a series of other disasters such as landslides, mudslides, and epidemics. Rain and waterlogging in my country

1951-1990. There are an average of 5.9 serious floods in my country every year, with an average affected area of ??6.67 million hectares, of which 4.7 million hectares are affected by disasters. Three to four thousand people died and more than 2 million houses collapsed. In 1991, floods of varying degrees occurred in 25 provinces, cities, and districts across the country. The affected area of ??crops was 24 million hectares, 5,133 people died, 4.98 million houses collapsed, and direct economic losses reached 79.9 billion yuan.

The main rain and flood areas are distributed in the east of the Greater Hinggan Mountains-Taihang Mountains-Wuling Mountains. This area is divided into four prone areas by Nanling Mountains, Dabie Mountains-Qinling Mountains and Yinshan Mountains. There is little rain in western my country, and only Sichuan is a rain-prone area.

According to historical rainfall statistics, the areas with the most severe rainfall are mainly the southeastern coastal areas, the Hunan-Jiangxi region, and the Huaihe River Basin. The areas with less severe rainfall include the middle and lower reaches of the Yangtze River, Nanling, Wuyi Mountains, and the Haihe River. and the lower reaches of the Yellow River, Sichuan Basin, Liaohe River, and Songhua River areas. The regions with the least rainfall in the country are the northwest, Inner Mongolia and the Qinghai-Tibet Plateau, followed by the Loess Plateau, the Yunnan-Guizhou Plateau and the northeastern region. In summary, the general characteristics of the distribution of rain and waterlogging are: more in the east and less in the west; more along the coast and less in the interior; more plains and lakes, less plateaus and mountains; more east and south slopes of mountains, less west and north slopes.

Flood disaster control and preventive measures Friday, May 16, 2008 09:44 Flood disaster control and preventive measures

Flood disaster is a common natural disaster. Flood disasters can lead to ecological environment, economic construction, property losses, and even the spread of infectious diseases, seriously threatening people's production, life and life safety. Due to the impact of heavy rainfall, some towns and villages suffered floods. In order to do a good job in disease prevention and control in the affected towns and villages, we have to achieve the goal of no major epidemics after the disaster. The following disease prevention and control measures are proposed for the reference of the affected towns and villages.

1. Strengthen drinking water sanitation management

1. Selection and protection of water sources; Drinking water intake points should be selected in the upstream of floods or in less polluted waters in waterlogging areas, and designated Outside a certain area, it is strictly prohibited to discharge feces, sewage and garbage in this area. In areas where conditions permit, docks should be set up at water intake points to facilitate water intake at a certain distance from the shore.

2. Selection of water sources after water recedes; in areas without running water, use well water as drinking water source as much as possible. Water wells should have well platforms, well rails, and manhole covers. Toilets, pig pens, and other facilities that may pollute groundwater are prohibited within 30 meters around the well. There should be a dedicated bucket for water collection. In areas where conditions permit, existing tap water supply pipelines can be extended. 3. Purify and disinfect drinking water; boiling is a very effective sterilization method. Filtering methods can be used when conditions permit.

However, during floods, the most important method of disinfecting drinking water is with disinfectants. 4. Strengthen the disinfection of water supply facilities; water sources or water supply facilities that have been flooded must be cleaned and disinfected before being reused, and the bacteriological indicators must be checked before they can be used again. Flooded wells must be desilted, flushed and disinfected. First, drain the well, remove the silt, rinse the walls and bottom of the well with clean water, and then drain out all the sewage. After the well naturally seeps to the normal water level, add bleaching powder and soak for 12 to 24 hours, then pump out the well water until the water naturally seeps back to normal. After the water level is reached, disinfect according to the normal disinfection method (add 4 grams of bleaching powder to one ton of water, or add 8 grams of bleaching powder per ton if the pollution is serious), and then it can be put into normal use.

2. Strengthen food hygiene management

1. Flood-stricken areas need to focus on preventing the following food poisoning

(1) Mycotoxin food poisoning caused by moldy food: Often caused by eating moldy rice.

(2) Bacterial food poisoning: often caused by animal foods, dead livestock and poultry meat, improperly refrigerated foods (such as meat, eggs) and cooked foods that have been stored for a long time (such as rice, vegetables).

(3) Chemical food poisoning: generally caused by accidental ingestion of toxic substances. Due to environmental changes in disaster areas and limited conditions in temporary residences, pesticides, nitrites and other industrial chemicals can easily be accidentally ingested.

(4) Toxic animal and plant food poisoning: Accidentally eating pig thyroid glands, adrenal glands and toxic fish can cause toxic animal food poisoning; eating soy milk, lentils or sprouted potatoes that have not been fully heated , Poisonous mushrooms can cause poisonous plant food poisoning.

2. On-site treatment of food poisoning

(1) Patient treatment and reporting: First aid treatment for patients mainly includes induction of vomiting, gastric lavage, enema, symptomatic treatment and special detoxification drugs Treatment: The contents of the food poisoning report include the place, time, number of people, typical symptoms and signs, treatment, poisoning food and measures taken. At the same time, attention should be paid to collecting patient specimens for examination.

(2) Stop eating poisoned food: Seal the poisoned food or suspected poisoned food at the site until investigation confirms that it is not poisonous food before eating it; notify to recover or stop eating poisoned food or suspected poisoned food from other places . (3) Disinfection of food and environment: harmlessly dispose or destroy poisoned food, and take corresponding disinfection treatment of poisoning sites. For bacterial food poisoning, solid food can be boiled and sterilized for 15 to 30 minutes; liquid food can be sterilized with bleaching powder. The patient's excrement and vomitus can be disinfected with 20% lime milk or bleaching powder (1 part excrement plus 2 parts disinfectant mixed and left for 2 hours), and the surrounding environment can be sprayed and disinfected with peracetic acid. In case of chemical or toxic animal or plant food poisoning, the poisonous substances causing the poisoning should be buried deeply.

3. Strengthen food hygiene supervision and management in disaster areas; especially flooded food production and operation units should clean and disinfect food equipment, containers, and the environment, and can only open after passing the inspection by the local health administrative department. , and strengthen supervision of its food and raw materials to prevent food contamination and the use of moldy and spoiled raw materials. 4. Carry out publicity and education on the prevention of food poisoning; mainly promote inedible foods, including: food soaked in water; dead livestock, poultry, and aquatic products; flooded and rotten vegetables and fruits; unknown sources Foods packaged in non-special food containers and without clear food labels; rice, wheat, corn, peanuts, etc. that are severely moldy (mold rate is more than 30%); other spoiled foods and mushrooms that cannot be identified as poisonous, etc. . 3. Strengthen environmental sanitation

1. Hygienic requirements for the residences of disaster victims; first, choose safe and higher-lying locations, and build temporary shelters such as tents, shacks, and simple houses, so that they can be resettled first and then improved. . Secondly, pay attention to the sanitation of the living environment, do not urinate or dump garbage and sewage in the open, and do not raise livestock and poultry in sheds. 2. Toilet sanitation and feces disposal measures (1) Choose a suitable location at the gathering point of disaster victims, make a reasonable layout, adapt to local conditions, and use local materials to build emergency temporary toilets. It is required that the septic tanks do not leak (or use ceramic jars, plastic buckets, etc. as a cesspool). (2) Try to make use of existing feces storage facilities to store feces. If there are no feces storage facilities, the feces can be mixed with soil and stored in mud seals, or covered with plastic film, and drainage ditches dug around to prevent rainwater from soaking and washing away. In case of emergency, dig a circular soil pit at a suitable slightly higher location, use waterproof plastic film as the lining of the soil, extend the film 20cm towards the edge of the pit, press it with soil, pour the feces into the pit for storage, cover and seal, and ferment deal with. You can also use larger-capacity plastic buckets, wooden buckets and other containers to collect feces, cover them after filling, and send them to a designated location for temporary storage until they are transported out for processing after the flood. If possible, use motorized fecal trucks to transport it away in time. (3) The feces of patients with infectious diseases under centralized treatment must be collected in special containers and then disinfected. Treatment of feces of scattered patients: The ratio of feces to bleaching powder is 5:1. After thorough mixing, they are buried together; an equal amount of lime powder is added to the feces, stirred and then buried together. Disposal of patient feces into streams is prohibited to prevent the spread of disease. 3. Garbage collection and disposal methods (1) According to the actual situation of the disaster victims’ gathering points, garbage collection stations should be reasonably arranged. Brick garbage pools, metal garbage cans (boxes) or plastic garbage bags can be used to collect domestic garbage. There should be dedicated personnel responsible for cleaning, Transportation, ensure daily cleanliness. (2) Transport the garbage out in time, choose a higher place for composting, and cover it with plastic film.

Dig drainage ditches around the area, and use chemicals to disinfect and kill insects to control fly breeding. (3) Some infectious waste can be treated by incineration. 4. Disposal of human and animal corpses: The corpses of normal deceased persons should be transported out as soon as possible for cremation. Those who die from Category A and B infectious diseases should be thoroughly disinfected and transported out for cremation as quickly as possible. Livestock, poultry and other animal carcasses removed during environmental cleanup should be treated with bleaching powder or quicklime and then buried deeply. 5. Environmental clean-up work after the floods recede; after the floods have receded, a mass patriotic health campaign will be carried out. On the basis of extensive health education, villages and households in flooded areas must conduct thorough indoor and outdoor environmental clean-ups to ensure that floods Wherever we retreat, environmental cleanup will be carried out, and disinfection, killing and eradication work will follow. (1) Organize and clean up the outdoor environment: repair roads, remove stagnant water, fill potholes, remove garbage and debris, eradicate weeds, clear ditches, remove sludge from wells, repair toilets and other sanitary infrastructure, and bury poultry Livestock carcasses are removed and the environment is disinfected to eliminate risk factors for disease occurrence and restore the environmental sanitation in the disaster area to pre-disaster levels in a short period of time. (2) For residents in flooded areas, after the water recedes, a special person will first conduct a safety inspection on the quality of the original house to confirm its firmness, then open doors and windows, ventilate, clean furniture and indoor items, renovate family toilets, and repair Comprehensive cleaning of poultry sheds and courtyards to remove garbage and dirt. Disinfect the walls and floors of the room if necessary. Daily necessities brought back indoors and from temporary settlements can be boiled and sterilized or exposed to sunlight. Wait until the room is ventilated, dry, and the air is fresh before you can move in. 6. Disinfection: Floods cause mixed contamination by a variety of microorganisms, among which intestinal pathogenic microorganisms are the dominant species. Therefore, special attention must be paid to the disinfection of food, drinking water, and living environments. In terms of the selection of disinfection methods and disinfectants, it is required to be simple and easy to implement, cheap and in sufficient supply. First of all, there should be dedicated personnel responsible for protecting water sources and disinfecting drinking water; at the same time, environmental sanitation and disinfection should be done well. Sanitation and disinfection of flooded houses and public spaces must be carried out by category. A dedicated person must be responsible for the centralized supply, preparation and public distribution of disinfectants, publicize disinfection knowledge, organize the public to implement disinfection measures and provide specific guidance on their correct use. 4. Control of infectious diseases 1. Strengthen preventive intervention measures in disaster areas; strengthen environmental sanitation management, remove garbage and filth, bury animal carcasses, manage feces and livestock, and improve the living environment. Actively protect water sources, carry out well drilling or drinking water disinfection, so that disaster victims can have clean drinking water. 2. Control the source of infection and block the route of transmission; in certain infectious disease epidemic areas, we should focus on controlling the source of infection, carry out rodent eradication activities in natural epidemic foci, remove mosquito and fly breeding grounds in densely populated areas of disaster victims, and effectively control and eradication of vector pests. Strengthen food hygiene management to prevent "diseases from entering the mouth" and control the occurrence of food-borne diseases. 3. Strengthen epidemic monitoring and establish an epidemic reporting network; During this extraordinary period of floods, special attention must be paid to epidemic reporting and epidemic monitoring, and the sensitivity of the epidemic monitoring system should be maintained. This is a prerequisite for disaster relief and disease prevention. When an infectious disease epidemic occurs, the epidemic must be actively dealt with according to the principles of "early detection, early reporting, early isolation, and early treatment." Establish epidemic monitoring points in key disaster areas or areas prone to infectious diseases and closely monitor epidemic dynamics. Once a major infectious disease epidemic or an unexplained disease outbreak occurs in the disaster area, it must follow the "Public Health Emergencies Emergency Regulations", "Public Health Emergencies and Infectious Disease Epidemic Monitoring Information Reporting Management Measures" and other laws and regulations. According to the requirements of regulations, timely feedback information, timely notification and alarm. In the event of a disease, especially an outbreak of an unknown disease, the responsible reporter should report the epidemic to the local disease control agency using the fastest communication method (direct online reporting within 2 hours, and report to the health administrative department at the same level by phone or fax at the same time), in order to take preventive decisions. At the same time, we will strengthen epidemic monitoring of the floating population to prevent cross-transmission of the epidemic. 4. Improve the level of population immunity and give full play to the effectiveness of planned immunity; floods disrupted normal work procedures, and the victims moved dispersedly, making it difficult to control the level of population immunity. It is necessary to carry out emergency vaccination and preventive medication for certain diseases, and carry out targeted strengthening of immunization and preventive medication to control the outbreak of infectious diseases in disaster areas. 5. Strengthen the health protection of special groups and maintain the health of disaster victims; special groups such as children, the elderly, the weak, the sick, the disabled, and pregnant women have poor physical resistance. Due to excessive fatigue and stress during the disaster, the harsh environment, malnutrition, and poor living conditions Stability, exposure to the sun, rain, and insect bites make it impossible to rest day and night. It is extremely easy to get sick due to the interplay of internal and external causes of the body. Therefore, preventive health care should be strengthened for this special population to control the epidemic of diseases. 6. Vigorously carry out patriotic health campaigns; improving the sanitary conditions in temporary residences is an important step in reducing the occurrence of diseases. It is also necessary to carry out publicity and education on health knowledge to develop good hygiene habits among disaster victims, and to encourage people not to drink raw water and wash their hands before eating and after using the toilet. 5. Vector control 1. Main measures to prevent mosquitoes (1) Environmental management; (2) Mosquito prevention and repellent: in disaster areas where conditions permit, install screen doors and windows in residences, or use mosquito nets soaked in drugs; sleep Light mosquito coils (or electric mosquito coils) before use; you can also use commercially available mosquito repellent to apply to exposed parts of the body. (3) Indoor (inside the tent) and outdoor spraying of drugs: such as dichlorvos, sodium chloride, trichlorfen, etc. 2. Anti-fly measures (1) Clean up the environment and reduce breeding places. (2) Spray pesticides indoors (in tents) and outdoors, or use sticky fly paper, fly traps or fly swatters to catch flies manually.

3. Rat eradication measures: Temporary settlements during floods are special environments. When carrying out rat eradication, you should pay attention to: (1) Use multiple instruments to eradicate rats, such as mouse cages and mouse traps, etc., but you cannot use electronic cats, let alone pull electric wires to catch rats. . At this time, the rat hole is shallow and water is easily available. Water or mud can also be used to fill the hole. (2) Use poison baits with caution: When the density of rats is very high, or the population is seriously threatened by rat-borne diseases, poison bait rodent control should be carried out on the basis of strict organization and sufficient publicity. (3) Ensure the safety of humans and animals: Poison bait cannot be prepared with cooked food, and the poison bait must have a warning color. The baiting work is undertaken by trained rodent exterminators, and the baiting points should be clearly marked. After baiting, dead rats should be searched for in a timely manner, livestock should be managed well, food should be preserved, and children should be taken care of. After the baiting is completed, the remaining bait should be collected and burned or buried deeply in an appropriate location. Health departments must be prepared for poisoning first aid. To avoid bites from insects that leave the rat's body after it dies, it is best to spray insecticides in the living area at the same time as killing the rats. 6. Health education: Health education in flood-stricken areas is an important guarantee for promoting the implementation of disaster relief and disease prevention measures. Health education must be adapted to the extraordinary period, extraordinary environment and extraordinary objects affected by disasters. The content of education must not only adapt to the psychology, culture, and quality of the education targets, but also be carefully organized according to changes in factors such as disaster conditions, weather, diseases, and health services, and changes in the level of health education needs of disaster victims.