Natural Threats & Hazards
Drought is a result of a natural decline of in the expected precipitation over an extended period of time, typically one or more seasons in length. A drought’s severity depends on numerous factors, including duration, intensity, and geographic extent as well as regional water supply demands. While the Sonoran Desert’s arid climate has subjected Maricopa County to drought conditions throughout its history, water management efforts have mitigated water shortages for the past century.
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Maricopa County frequently exceeds temperatures of 110 degrees Fahrenheit in the summer months, but is fortunate enough to have relatively low humidity. Extreme heat is defined as the presence of high temperatures combined with high humidity. Common hazards associated with extreme heat include serious or fatal medical conditions such as heat cramps, heat syncope, heat exhaustion, and heat stroke.
Compounding the issue is the added strain on air conditioning equipment and power utility supplies under such extreme heat conditions. Loss of power and cooling could increase the risk of heat illnesses to those unable to cool themselves. It is recommended to remain in an air conditioned environment during the extreme heat and to drink lots of water, especially for young children and senior adults. Should there be a long-term loss of power during high (or very low) temperatures, public shelters may be made available to those in need.
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Extreme Heat Resources
A fissure is a crack in the earth’s surface that extends from the groundwater table that results from differences in soil settling. These fissures can range in width from inches to tens of feet and can be miles in length. Fissures can damage underground utilities, infrastructure, roadways, and building foundations. They may also cause injuries, breach canals, and alter flood patterns or flood control measures.
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Localized flooding is a result of excessive precipitation/storm runoff over a short period of time. In addition to heavy rain; poorly designed/ maintained, altered, or blocked control measures often contribute to these localized floods. The three types of storms that tend to trigger flooding in Maricopa County are Tropical storm remnants, Winter rains, and Summer monsoons.
Flash floods result from storm runoff from local or distant mountainous areas moving quickly through normally dry washes and riverbeds, and can also occur on surface streets throughout the valley. These common types of floods are fast moving and often short lived. Although the water may not look deep or swift moving, driving through these flooded riverbeds or washes is not only dangerous, but also unlawful. Use caution when approaching flash flood areas; and when in doubt, turn around and find an alternate route.
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Severe winds in Maricopa County come in three forms: downbursts, straight line winds, and tornados. Tornados are rapidly rotating funnels of air that stretch from the sky to the ground. These funnels become tornados once they touch the ground and can cause severe damages and are life threatening. All three of these wind types can create dust storms, uproot trees, and topple power poles.
While tornados are less common in Maricopa County, downburst and straight winds are frequent, especially during the summer monsoons. Downbursts, also referred to as macro or micro-bursts, are massive columns of air that move rapidly downward through a thunderstorm. When the air hits the ground, it disperses air horizontally at speeds in excess of 80 MPH, capable of causing injuries and damages similar to that of a tornado. Strait line winds originate from thunderstorms that force sustained winds to travel parallel to the ground. They can exceed wind speeds of 75 MPH and frequently cause dust storms that seriously limit visibility.
Should you be caught in a dust storm while driving, safely pull over to the side of the road, turn off your lights, put your car in “Park”, and take your foot off the brake (so other cars don’t follow your lights). Wait out the dust storm until visibility improves.
More information on Severe Wind and Dust Storms
Subsidence is the gradual sinking of land resulting in the removal or depletion of underground fluids, such as groundwater, or the excessive use of surface water, such as in farming. Subsidence can cause drainage problems for storm waters, flood control pattern reversal, or flow problems for canals and liquid infrastructure (waterlines/sewer).More Information on Subsidence
Wildfires often begin unnoticed but quickly spread and produce a noticeable dense smoke that can be seen for miles. Although many in the valley live in urban areas, other areas have what is called a “Wildland Urban Interface”, which creates an environment where fire can move readily between structures and vegetation. Residential and commercial expansion into these areas can increase the likelihood that wildfires may threaten structures and people, and are both dangerous and costly to fight.
Wildfires can be started by nature through lightning strikes and dry, hot weather conditions, but can also be human-caused by accident, carelessness or criminal intent. Maricopa County’s summer high temperatures and dry climate provide a combustible environment for all of these ignition methods. The lingering effects of a wildfire may include soil erosion, landslides, and reduced food for the local animal population.
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