A flood is a natural disaster caused by too much rain or water in a location, and could be caused by many different sets of conditions. Floods can be caused by prolonged rainfall from a storm, including thunderstorms, rapid melting of large amounts of snow, or rivers which swell from excess precipitation upstream and cause widespread damage to areas downstream, or less frequently the bursting of man-made dams. A river which floods particularly often is the Huang He in China, and a particularly damaging flood was the Great Flood of 1993.
Drowning is caused by suffocation when a liquid causes interruption of the body's absorption of oxygen from the air leading to asphyxia. The primary cause of death is hypoxia and acidosis leading to cardiac arrest.
Drowning is one of the major causes of death for children under 14 years old. Children have drowned in wading pools and even bath tubs. There is also a correlation of the rate of drowning in populations around the world and their access to water, the climate and the national swimming culture. For example, typically the United Kingdom suffers 450 drownings per annum or 1 per 150,000. Of population whereas the United States suffers 6,500 drownings or around 1 per 50,000 of population.
So the risk or drowning seems related to the situation and awareness of the danger allied to the capacity correctly ascertain one's capacity to extrude oneself from the danger of drowning.
The reduction of drowning through education has become a significant element of school curricula and is integrated into most water sports training. The elements incorporated into this training vary according to the particular context.
Most current training emphasizes the need to:
- Learn to swim
- Learn and practice water rescue.
- Know personal strengths and limitations in the water.
- Stay within one's depth unless a strong swimmer.
- Keep a watch out for others.
- Swim with company, finding a buddy, children to swim with a responsible adult.
- Ensure that children have competent supervision in or near water.
- Swim in areas supervised by lifeguards in preference to areas without.
- Be cautious and very conservative when swimming at night.
- Ensure that boats are reliable, properly loaded and that functional emergency equipment is onboard.
- Wear a properly fitting lifejacket while enjoying water sports such as sailing, surfing or canoeing.
- Pay attention to the weather, tides and water conditions, especially currents. Currents always look weaker from the outside!
- Have a fence around swimming pools.
- Consider cold-acclimatisation training for swimming in very cold water, by joining a winter swimming club.
Most current training emphasizes the need to avoid:
- Swimming while drunk or on drugs.
- Using hyperventilate to extend a breath-hold dive, see deep and shallow water blackout
- Relying on swimming aids as they may fail.
- Playing games that will put your life, or others', at risk.
- Pretending to be a drowning victim, unless ALL bystanders are informed that this is an exercise.
- Diving into water where the bottom cannot clearly be seen or depth determined.
- Walking on ice unless it is known absolutely that the ice is thick enough over the entire route.
- Handling electrical devices in or near the water.
- Exceeding personal limits.
- Swimming in cold water unless first, fully cold-acclimatised and experienced winter swimmer.
Drowning risk situationsEdit
Most drownings occur in water, freshwater (rivers and lakes, pools, etc) or in seawater, drownings in other fluids are rare and are often industrial accidents.
Common conditions that may lead to drowning include but are not limited to:
- Water conditions exceed the swimmer's ability; - turbulent or fast water, water out of depth, falling through ice, rip currents, undertows, currents, waves and eddies.
- Entrapment; - physically unable to get out of the situation because of a lack of an escape route, snagging or by being hampered by clothing or equipment.
- Impaired judgment and physical incapacitation arising from the use of drugs, principally alcohol.
- Incapacitation arising from the conditions; - cold (hypothermia), shock, injury or exhaustion.
- Incapacitation arising from acute illness while swimming; - heart attack, seizure or stroke.
- Forcible submersion by another person; - murder or misguided children's play.
- Blackout underwater after rapid breathing to extend a breath-hold dive; - shallow water blackout.
- Blackout on ascent from a deep breath-hold dive due to latent hypoxia; - deep water blackout.
People have drowned in as little as 30mm of water lying face down, in one case in a wheel rut. Children have drowned in baths, buckets and toilets; inebriates or those under the influence of drugs have died in puddles. For a more detailed list of causes see swimming.
Rescue and treatmentEdit
Many pools and designated bathing areas either have lifeguards, a pool safety camera system for local or remote monitoring, or computer aided drowning detection. However, bystanders play an important role in drowning detection and either intervention or the notification of authorities by phone or alarm. No person should attempt a rescue that is beyond his or her ability or level of training.
If a drowning occurs or a swimmer becomes missing, bystanders should immediately call for help. The lifeguard should be called if present. If not, emergency medical services and paramedics should be contacted as soon as possible.
The first step in rescuing a drowning victim is to ensure your own safety. Then bring the victim's mouth and nose above the water surface. For further treatment it is advisable to remove the victim from the water. Conscious victims may panic and thus hinder rescue efforts. Often, a victim will cling to the rescuer and try to pull himself out of the water, submerging the rescuer in the process. To avoid this, it is recommended that the rescuer approach the panicking victim with a buoyant object, or from behind, twisting the victim's arm on the back to restrict movement. If the victim pushes the rescuer under water, the rescuer should dive downwards to escape the victim.
Actively drowning victims do not usually call out for help simply because they lack the air to do so. It is necessary to breathe to yell. Human physiology does not allow the body to waste any air when starving for it. They rarely raise their hands out of the water. They use the surface of the water to push themselves up in an attempt to get their mouths out of the water. Lifting arms out of the water always pushes the head down. Head low in the water, occasionally bobbing up and down is another common sign of active drowning.
There can be splashing involved during drowning, usually a butterfly like stroke where the hands barely clear the waters surface, and sometimes victims can look like they are climbing an invisible ladder in the water.
Extenuating factors such as increased levels of stress, secondary injuries, and environmental factors can increase the likelihood of distress and/or drowning in persons who end up overboard. It is important that you recognize the behaviors associated with aquatic distress and drowning, so you can make informed decisions during emergencies.
Signs or behaviors associated with drowning or near-drowning:
- Head low in the water, mouth at water level
- Head tilted back with mouth open
- Eyes glassy and empty, unable to focus
- Eyes closed
- Hair over forehead or eyes
- Hyperventilating or gasping
- Trying to swim in a particular direction but not making headway
- Trying to roll over on the back to float
- Uncontrollable movement of arms and legs, rarely out of the water.
After successfully approaching the victim, negatively buoyant objects such as a weight belt are removed. The priority is then to transport the victim to the water's edge in preparation for removal from the water. The victim is turned on his or her back. A secure grip is used to tow panicking victims from behind, with both rescuer and victim laying on their back, and the rescuer swimming a breaststroke kick. A cooperative victim may be towed in a similar fashion held at the armpits, and the victim may assist with a breaststroke kick. An unconscious victim may be pulled in a similar fashion held at the chin and cheeks, ensuring that the mouth and nose is well above the water.
There is also the option of pushing a cooperative victim lying on his or her back with the rescuer swimming on his or her belly and pushing the feet of the victim, or both victim and rescuer lying on the belly, with the victim hanging from the shoulders of the rescuers. This has the advantage that the rescuer can use both arms and legs to swim breaststroke, but if the victim pushes his or her head above the water, the rescuer may get pushed down. This method is often used to retrieve tired swimmers. If the victim wears lifejacket, buoyancy compensator, or other flotation device that stabilizes his or her position with the face up, only one hand of the rescuer is needed to pull the victim, and the other hand may provide forward movement or may help in rescue breathing while swimming, using for example a snorkel.
Special care has to be taken for victims with suspected spinal injuries, and a back board (spinal board) may be needed for the rescue. In water, CPR is ineffective, and the goal should be to bring the victim to a stable ground quickly and then to start CPR.
If the approach to a stable ground includes the edge of a pool without steps or the edge of a boat, special techniques have been developed for moving the victim over the obstacle. For pools, the rescuer stands outside, holds the victim by his or her hands, with the victim's back to the edge. The rescuer then dips the victim into the water quickly to achieve an upward speed of the body, aiding with the lifting of the body over the edge. Lifting a victim over the side of a boat may require more than one person. Special techniques are also used by the coast guard and military for helicopter rescues.
After reaching dry ground, all victims should be referred to medical assistance, especially if unconscious or if even small amounts of water have entered the lungs. An unconscious victim may need artificial respiration or CPR.
The Heimlich maneuver is not recommended; the technique may have relevance in situations where airways are obstructed by solids but not fluids. Performing the maneuver on drowning victims not only delays ventilation but may induce vomiting, which if aspirated will place the patient in a far worse situation. Moreover, the use of the Heimlich maneuver in any choking situation, involving solids or fluids, has become controversial and is generally no longer taught. For more information on this debate refer to the article Henry Heimlich.
100% oxygen is highly recommended, including intubation if necessary. Treatment for hypothermia may also be necessary. Water in the stomach need not be removed, except in the case of pediatric drownings as a gastric distension can limit movement of the lungs. Other injuries should also be treated (see first aid). Victims that are alert, awake, and intact have nearly a 100% survival rate.
Drowning victims should be treated even if they have been submerged for a long time. The rule "no patient should be pronounced dead until warm and dead" applies. Children in particular have a good chance of survival in water up to 3 minutes, or 10 minutes in cold water (10 to 15 °C or 50 to 60 °F). Submersion in cold water can slow the metabolism drastically. There are rare but documented cases of survivable submersion for extreme lengths of time. In one case a child named Michelle Funk survived drowning after being submerged in cold water for 70 minutes. In another, an 18 year old man survived 38 minutes under water. This is known as cold water drowning.