DISCUSSION: Portions of the mid-west and mid-Atlantic experienced massive flooding during the latter part of this past February. Residents in the Mid-Ohio Valley were urged to evacuate as well as prep their homes and businesses for the Ohio River’s impending invasion. Residents along the Monongahela River in West Virginia were also urged to prepare for flash flooding and possible property damage.
Flooding is among our planet’s most common – and most destructive – natural disaster. While certain areas are more prone to flooding, wherever rain falls is vulnerable. The most common flooding occurs when water inundates land that’s normally dry, usually due to river or stream beds overflowing their banks. Ice jams, excessive rain, or failed levees/dams can also irritate a river, causing it to spill out over the adjacent land (floodplain). Coastal flooding can occur due to a large storm system off the coast or even a tsunami, both of which causes sea water to rush inland.
Most floods typically take hours, sometimes days, to develop which gives residents and city management teams plenty of time to prep or evacuate. Others occur rapidly, with little to no warning. These are called “flash floods” and can be exceptionally dangerous, instantly transforming a calm creek into a massive wall of water, taking everything it its path downstream.
Experts classify floods according to their likelihood of occurring in a certain time frame. For example, “a hundred-year flood” is a large, destructive flood that in theory should be expected once every century. In all reality, this classification simply means there is a 1% chance that a flood to that magnitude could occur in any given year. Throughout the recent decades, these massive “hundred-year floods” have been occurring worldwide with unprecedented regularity.
Water, especially when moving, has awesomely destructive power. When a river spills water over its banks or the sea moves inland, poorly equipped structures cannot withstand the strength of the rushing water. Homes, bridges, cars, and other debris can be picked up and carried off. Moving water also has an erosive force, able to drag dirt from under a building’s foundation, ultimately causing it collapse.
In the United States, where severe weather prediction is advanced, floods cause upwards of $6 billion in damage and kill 140 a year. A 2007 report filed by the Organization for Economic Cooperation and Development discovered that coastal flooding alone causes nearly $3 trillion in damage worldwide.
When the floodwaters recede, it’s often that affected areas are covered in silt and mud. Occasionally the water and newly transformed landscape can be contaminated with hazardous materials such as pesticides, fuel, raw sewage, and other debris. Another potential danger is mold blooms quickly overtaking water-soaked structures. Residents of flooded areas can be left without basic necessities such as power and clean drinking water, possibly leading to outbreaks of waterborne diseases.
Flooding, especially in river floodplains, is natural and has been occurring for millions of years. Fertile floodplains like the Mississippi Valley in the Midwest, the Nile in Egypt, and the Tigris in the Middle East have been a life source for millions of years thanks to annual flooding leaving behind a plethora of nutrient-rich silt deposits behind.
Most of the destruction that comes from flooding can be attributed to society’s desire to live near coastlines and river valleys. It’s a common practice for city governments to mandate residents in flood-prone areas to purchase flood insurance and build flood-resistant structures. Massive efforts to manipulate and redirect inevitable floods have resulted in brilliant engineering efforts, including the extensive levee system in New Orleans as well as effective dikes and dams in Holland.
Scientists, meteorologists, and engineering are constantly working towards bettering our forecasting and infrastructure. Highly advanced computer modeling now allows disaster authorities and forecasters to predict with high accuracy as to where floods will occur and just how severe they could be.
To learn more about other interesting global flooding stories and/or topics, be sure to click on the following link: www.globalweatherclimatecenter.com/flooding.
© 2018 Meteorologist Ash Bray
DISCUSSION: There is little to no argument across the global scientific community that the Earth has for quite some time been and still is continuing to experience net planetary warming. One of the premiere concerns in the presence of an increasingly warmer planet are the prospects of heavier rainfall events occurring with a greater frequency and intensity both across the contiguous United States and all over the world for that matter. This a direct result of the fact that as the Earth continues to experience a net global heating trend, this consequentially increases the average global concentration of atmospheric water vapor. As this gradual average increase in atmospheric water vapor content occurs, this increases the propensity of heavy rainfall event potential by way of there being more atmospheric water vapor available in the lower to middle parts of the atmosphere for developing storm systems (i.e., whether they be in the form of thunderstorms or much larger-scale extra-tropical cyclones).
Hence, in the presence of a warming planet, the threat for a greater frequency of heavy rainfall events has many regional, national, and international scientists (and specifically hydrologists) rather concerned. This is because an occurrence of heavy rainfall events with a greater average frequency also adds the possibility of their being a greater propensity for river and stream flooding events which consistently have the potential to inundate towns and cities both near and far from the given waterway. To better understand the reason for the major concerns tied to the percentage increase in heavier precipitation events over the 55 + years, there are direct excerpts from the actual article written by the Climate Central team.
"A warmer world supercharges the water cycle, leading to heavier precipitation. To start, a warmer atmosphere creates more evaporation — for every 1°F of warming, the saturation level is increased by about four percent. With more water evaporating into the atmosphere, there is more available to condense into precipitation, and it’s coming down in bigger downpours...............Even in the absence of urban development where there is more rain runoff, heavy rain will lead to more flooding. This means extreme flooding will become more common, resulting in more property damage. Over time, flood maps may have to be redrawn, which will have an impact on property values and insurance rates. Damage from the 2016 Louisiana floods was $10.4 billion and totaled $125 billion from Harvey."
To read more about this particular story, click on the following link.
To learn more about other high-impact flooding and flooding-related stories from around the world, be sure to click here!
© 2018 Meteorologist Jordan Rabinowitz