Weather and geographical factors both impact the severity of the flooding and how high the water percentage will be in a region. Natural disasters, such as those listed above, are the cause of coastal floo ding. Flood damage causes severe structural damage.
This is when tsunamis or hurricanes create large waves that eventually reach the shore and flood the coastal area. Most floods take hours or days to form, which gives residents time to evacuate safely. Flash floods , however, form as quickly as three to six hours after the initial cause and are considered very dangerous for this reason.
Flash floods are often caused by:. The speed at which flash floods form is determined by a variety of geographical factors, such as the location and intensity of the rainfall or other cause. Urban areas are often more at risk of flash floods than suburban or city areas because the water overruns low spots after it is unable to absorb into the impregnable ground. Flash floods give residents less time to evacuate and they may become trapped in their homes or another building.
If residents are lucky enough to evacuate to safety, they likely will not be able to properly protect their homes beforehand, due to the speed and severity of flash flooding. Death is the most severe effect a flood can have on a community, and floods kill more people in the U. Injury and disease lead more people to local hospitals, which may have been destroyed in the flood. From to , the National Weather Service recorded hundreds of flooding deaths across the United States.
Texas saw most of those deaths, with the 8-year total sitting at fatalities. Since it only takes two feet of flood water to wash a car away, flooding can also cause great loss of property. This is why it is so important to avoid flooded areas when driving. Flooding also causes property damage to buildings by blowing out windows, sweeping away doors, corroding walls and foundations, and sending debris into infrastructure at a fast pace.
Not to mention the furniture and items inside a home or business that are damaged when flood waters make it inside. The economic impact of flooding can be devastating to a community. This comes from damage and disruption to things like communication towers, power plants, roads, and bridges.
This brings business activities in an area to a standstill. Oftentimes, major flooding results in dislocation and dysfunction of normal life long after flood waters recede. Flooding hinders economic growth and development because of the high cost of relief and recovery associated with floods. In frequently flooded areas, there is less likely to be any investment in infrastructure and other developed activities.
Flooding can also create lasting trauma for victims. The loss of loved ones or homes can take a steep emotional toll, especially on children. While floods have many causes, there are proven flood safety and flood prevention tips to help keep families, businesses, and communities safe. Here are some steps you can take before, during, and after flooding to keep yourself and those you care about safe. The first thing you should do before a flood is assemble an emergency kit. Your flood emergency kit should include food, water, and medicine.
You should pack a supply of these items that will last each person three days. You should also put the following in your kit:. Phone Charger. First Aid Kit. Rubber Boots and Gloves. You should also have a cell phone on hand. This way, you can communicate with your friends, family, and coworkers. Are you located in a flood plain? Knowing the answers to these questions can help you in the case of floods. One last flood tip we recommend is to sign up for flooding notifications.
Familiarize yourself with your local emergency management agency and how they communicate with your community. Do they have a mobile app you can download? Should you follow them on social media? Will an announcement about flooding air on the TV or local radio stations? Finally, for hyperlocal weather alerts that include NWS flooding notifications, current precipitation information, and rainfall totals in your neighborhood, you should look into getting a subscription to professional-grade weather tracking software.
The first level of flood watches and warnings is a flood advisory. A Flood Advisory means you should be mindful of possible flooding because a weather event is forecast to occur that could result in flooding. A Flood Watch means you should prepare for flooding because conditions are favorable for a specific hazardous weather event to occur.
A Flood Warning means a hazardous weather event with flooding is imminent or already happening. Our AEM sister company, OneRain the Rainfall Company , specializes in helping clients understand and manage their water-related missions, including flood and road weather safety.
You may be wondering, what is a Flood Warning System? According to OneRain, a complete, integrated flood early warning monitoring system solution includes all the remote site hydro-meteorological sensing instrumentation, communications equipment, central base station equipment, as well as data collection, archiving, processing, and management software designed for flood warning.
Contrail for Flood Warning is an effective OneRain software solution for flood warnings. The software continually collects and monitors rainfall, water level and flow data in streams, rivers, lakes, and dams in real time. Contrail is an enterprise-level software solution that continually collects and monitors rainfall, water level and flow data in streams, rivers, lakes, and dams in real time.
It is critical to remain safe during flood watches and warnings so as to avoid flood fatalities. A Flash Flood Warning means a flash flood is imminent or occurring. If you are in a flood prone area move immediately to high ground. You should always pay attention to these notifications and understand what the different levels mean. For businesses, access to real-time flood watches and warnings through a hyperlocal weather map like Sferic Maps can help keep employees safe and protect outdoor equipment from being damaged during a flooding event.
If a flood event is happening, there are steps you can take to stay safe. The first and most important thing to remember is to steer clear of flood waters. This is true even if you are in a car. Flood waters can rise or gain intensity in the blink of an eye. Stay away from flood water at all costs. Another important tip that will help you survive a flood is to listen to evacuation orders from authorities.
We also stress that you listen to evacuation orders the first time you hear them. Waiting even just a few minutes can be the difference between life and death. And staying behind can put you and others at risk if you need to be rescued from rising waters. One last useful flood safety tip to pay attention to during a flood is to stay away from rooms where water covers electrical outlets. Your National Weather Service recommends purchasing a radio that has both a battery backup and a tone-alert feature which automatically alerts you when a watch or warning is issued.
Families should be prepared for all hazards that affect their area. Where will your family be when disaster strikes? They could be anywhere at work, at school, or in the car. How will you find each other? Will you know if your children are safe? Disasters may force you to evacuate your neighborhood or confine you to your home.
What would you do if basic services water, gas, electricity or telephones were cut off? Follow these basic steps to develop a family disaster plan Practice and maintain your plan. Ask questions to make sure your family remembers meeting places, phone numbers, and safety rules. Conduct drills. Test your smoke detectors monthly and change the batteries at least once a year. Test and recharge your fire extinguisher s according to manufacturer's instructions.
Replace stored water and food every six months. Skywarn Skywarn Page What is Skywarn? Please Contact Us. Please try another search. Multiple locations were found. Please select one of the following:. Location Help. The storm surge that accompanied the Bhola cyclone flooded the low-lying islands of the Ganges Delta in India and Bangladesh.
More than , people were killed, and twice that number were left homeless. The strong winds associated with hurricanes and cyclones can also whip up and move huge amounts of water, forcing a storm surge far inland.
The city of New Orleans, Louisiana, was particularly hard-hit. Levees protect New Orleans from the Mississippi River.
The river rushed in and flooded entire neighborhood s. Man-Made Causes of Floods Floods can also have man-made sources. Many man-made floods are intentional and controlled.
Rice farmers, for instance, rely on flooded fields. Rice is a semi-aquatic crop—it grows in water. After rice seedling s are planted, farmers flood their fields, called rice paddies, in about 15 to 25 centimeters 6 to 10 inches of water.
Rice paddies must be carefully engineered to allow controlled flooding. Strong dike s or levees, as well as regulated channel s for irrigation , are required. Sometimes, engineer s flood an area to restore an ecosystem. In , the Grand Canyon was deliberately flooded. Water was released from dams on the Colorado River , which runs through the Grand Canyon.
Hydrologist s, engineers, and environmentalist s hoped that flooding the canyon would help redistribute sediment—which had been blocked up by dams—and create sandbar s. Sandbars provide a wildlife habitat , often serving as a shallow bridge for animals such as beavers and bighorn sheep to cross from one side of the river to the other.
Dams control the natural flood plains of lakes and rivers. Hydrologists may intentionally flood areas to prevent damage to the dam or increase the water supply for agriculture, industry , or consumer use. Engineers may also intentionally flood areas to prevent the possibility of worse flooding.
When heavy rains caused the Souris River to flood in , for example, the water level nearly reached the top of the Alameda Reservoir in Oxbow, Saskatchewan, Canada. Faced with the prospect of catastrophic flooding if the entire dam broke, engineers chose to release huge amounts of water. The reservoir remained intact , but the release contributed to massive floods in both Saskatchewan and the U.
Not all man-made floods are intentional, however. The natural banks of rivers and streams shrink as people develop land nearby. River banks are valuable real estate for housing, businesses, and industry. In rural areas, factories use river current s to distribute runoff.
To accommodate such development , river banks are paved with hard, non-porous materials. An unusual amount of rain can cause these rivers to quickly overrun their concrete banks. Streets, downtown business districts, and bridges were destroyed. Concrete banks also increase the amount of runoff flowing to nearby bodies of water. This increases the risk of coastal flooding. Venice, Italy, for instance, is frequently flooded as tides from the Adriatic Sea seep into the heavily developed island s on which the city rests.
Hydrologists, engineers, and city planner s constantly work to reduce flood damage. Shrub s and plants create buffer s to prevent runoff from seeping into flood plains, urban areas, or other bodies of water. The thick vegetation between a river and a flood plain is called a riparian zone. Despite their efforts, people can also radically fail to control floods. The most famous flood in American history, the Johnstown Flood , was a man-made disaster. The tragedy killed 2, people and made headlines around the country.
Johnstown, Pennsylvania, was on a flood plain at the meeting of the Stony Creek and Little Conemaugh rivers. As more people moved to the city, the banks of the rivers were paved and narrowed, causing yearly flooding. Residents were prepared for this. They watched the river and moved their belongings upstairs or onto rooftops as the city flooded.
However, residents were not prepared for the additional flood from an entire lake. The lake was an exclusive retreat for members of the South Fork Fishing and Hunting Club, which owned the dam. Lake Conemaugh contained 20 million tons of water. On May 31, , the dam broke and the water rushed down the river at 64 kilometers per hour 40 miles per hour.
The flood destroyed a wire factory, filling the water with tons of barbed wire. About 80 people died when floating wreckage caught fire. Rebuilding Johnstown took years—the bodies of some victims were not found until 20 years later. The most common classifications are a year flood, a year flood, and a year flood.
A year flood, for example, is an extremely large, destructive event that would be expected to happen only once every century. But this is only an estimate. In recent decades, year floods have occurred more frequently. This may be due to global warming , the current period of climate change. Anything over 8. In , the river crested at almost 12 meters 40 feet , a record level.
In , the record was beaten as the river flooded again, reaching a height of almost The river flooded for 61 days. Flash flood s can develop within hours of heavy rainfall.
Flash floods can be extremely dangerous, instantly turning a babbling brook into a thundering wall of water that sweeps away everything in its path.
Most deaths from flooding occur as a result of flash floods. Flash floods do not have a system for classifying their magnitude. Desert s are vulnerable to flash floods.
Wadi s and arroyo s are dry river beds that only flow during heavy rains. The city of Jeddah, Saudi Arabia, developed on the site of several wadis, and floods are frequent after heavy rains. More than people died in flash floods in Jeddah in The floods developed so quickly that many victims drowned in their cars as streets became submerge d. Predicting Floods Today, hydrologists study past flood patterns to help predict where and when floods will happen in the future.
The predictions are only estimates, however. Weather , land, and climate can all change. Agricultural soil, for instance, can absorb much more water than sand or bare rock. Groundwater is water already in the earth—in soil, underground reservoirs called aquifer s, and even porous rocks. The type of soil and the amount of groundwater tells hydrologists how much more water the earth can absorb.
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