Weather-Related Natural Hazards

Hurricanes, heat waves, floods, and droughts are all natural disasters that can lead to damage of property, land, ecosystems and human fatalities.  

Hurricanes are warm, low-pressure systems without any front attached. They develop over tropical ocean waters. Although hurricanes are known for their heavy winds, the storm surge is by far the greatest threat to life and property along the coast. A storm surge is the water pushed toward the shore by the force of the winds; this advancing surge of water combines with normal tides to create a wall of water that can be15 feet higher than the normal water level. This rise in water level can cause severe flooding, especially if the storm surge coincides with high tide. Because much of the US's densely populated Atlantic and Gulf coast coastlines are less than 10 feet above mean sea level, the danger from storm tides is tremendous. 

Hurricane Sandy.  Photo courtesy of NOAA. 

Flooding occurs when too much precipitation falls in an area and rivers and streams overflow their banks. Flooding also can occur due to storms, such as hurricanes. Levees are often built to keep water from damaging nearby structures, but they can fail. Water can flow over the levee if it's not high enough to contain the flood waters, or water can sometimes seep through them because they are often built from compacted earth. Areas can become more susceptible to flooding due to urban development; pavement doesn't allow water to infiltrate the ground. Also, loss of plants and trees leads to the lessening of soil's ability to absorb runoff and can lead to flash flooding. 

Heat waves can be deadly, and happen when mean temperatures are higher than normal in an area. Heat waves can cause harm to humans and damage crops. They are caused when a persistent high pressure system remains over a region for at least several days. 

Droughts occur when less precipitation than usual falls in an area. The western US has been experiencing a drought; changes in climate over the Colorado river watershed are reducing the amount of fresh water available in the river.  The most famous drought in US history resulted in the Dust Bowl during the 1930s. 

Drought conditions in the US for February 11, 2014. Map courtesy of NIDIS. 

Sources: Hurricanes. Retrieved from NOAA on February 19, 2014. 

Last modified: Wednesday, 19 February 2014, 9:04 AM