Geography can also make an area more likely to flood. For example, areas near rivers are often at risk for floods. Urban areas areas near cities are also at higher risk for floods because rooftops funnel rainfall to the ground below, and paved surfaces such as highways and parking lots prevent the ground from absorbing the rain.
Flooding in the streets of downtown Cedar Rapids, Iowa. Paved surfaces can't absorb rain, so urban areas are at risk for flooding. Rain or snowmelt running down a mountain can cause streams and rivers to rise quickly. In fact, if a thunderstorm lingers over a mountain, a creek only 6 inches deep can swell to a foot-deep river in less than an hour.
Flash floods are very dangerous floods that can happen with little or no warning. When there is more rain than the soil can absorb, the excess water quickly runs into rivers and creeks, overwhelming storm drains and ditches and causing a flash flood. Flash floods can cause water to rise significantly in a short amount of time. Several different weather conditions can cause extreme rainfall in a region.
Tropical cyclones form in some tropical and subtropical areas, usually in the summer and fall. A flood occurs when water inundates land that's normally dry, which can happen in a multitude of ways. Excessive rain, a ruptured dam or levee , rapid melting of snow or ice, or even an unfortunately placed beaver dam can overwhelm a river, spreading over the adjacent land, called a flood plain.
Coastal flooding occurs when a large storm or tsunami causes the sea to surge inland. Most floods take hours or even days to develop, giving residents time to prepare or evacuate. Others generate quickly and with little warning. So-called flash floods can be extremely dangerous , instantly turning a babbling brook or even a dry wash into rushing rapids that sweep everything in their path downstream.
Climate change is increasing the risk of floods worldwide, particularly in coastal and low-lying areas, because of its role in extreme weather events and rising seas. The increase in temperatures that accompanies global warming can contribute to hurricanes that move more slowly and drop more rain , funneling moisture into atmospheric rivers like the ones that led to heavy rains and flooding in California in early Meanwhile, melting glaciers and other factors are contributing to a rise in sea levels that has created long-term, chronic flooding risks for places ranging from Venice, Italy to the Marshall Islands.
More than U. People walk on a catwalk in a flooded St. Mark's Square during a period of seasonal high water in Venice, Italy, on October 29, In the U. Death tolls have increased in recent decades to more than people a year. In China's Yellow River Valley some of the world's worst floods have killed millions of people. When floodwaters recede, affected areas are often blanketed in silt and mud. The water and landscape can be contaminated with hazardous materials such as sharp debris, pesticides, fuel, and untreated sewage.
Potentially dangerous mold blooms can quickly overwhelm water-soaked structures. Residents of flooded areas can be left without power and clean drinking water, leading to outbreaks of deadly waterborne diseases like typhoid, hepatitis A, and cholera. Learn here about flood preparation and safety tips. Flooding, particularly in river floodplains, is as natural as rain and has been occurring for millions of years.
Famously fertile floodplains such as the Mississippi Valley, the Nile River Valley in Egypt, and the Tigris-Euphrates in the Middle East have supported agriculture for millennia because annual flooding has left tons of nutrient-rich silt deposits behind. Storm surges from hurricanes and other tropical systems can cause sea levels to rise and cover normally dry coastal areas in several feet of water.
Tsunamis on the other hand are giant waves caused by earthquakes or underwater volcanic eruptions. As these waves move inland, they build height and can push a lot of water inland in coastal areas. Channels with steep banks are also to blame for flooding. Flooding often occurs when there is fast runoff into lakes, rivers, and other basins. This is often the case with rivers and other channels that feature steep sides.
A lack of vegetation can cause flooding. Vegetation can help slow runoff and prevent flooding. When there is a lack of vegetation, there is little to stop water from running off and overflowing river banks and streams. Melting snow and ice is another common reason for flooding.
No matter what causes of a flood, it can have devastating effects on your community. There are actually many dangerous flooding effects. Besides physical danger, floods also cause economic and social problems. The gravest effect of flooding is death. In fact, flooding is the number one severe weather killer.
Floods have claimed thousands of lives throughout history. But how does flooding kill? Floods kill by carrying people away in fast-moving water or drowning them. It only takes six inches of water to wash a person away. Floods can also kill people by destroying buildings and creating unsafe environments. One often-overlooked deadly effect of flooding comes from waterborne illnesses. 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.
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