Unprecedented fire storms that have destroyed most of Southern California will probably fit in the end, with the long -awaited rain. However, it may not have much time to rest for emergencies and public works. If it rains after a fire, the danger of landslides and debris flow to test the limit of local infrastructure will increase.
The wildfire takes the plant from the slope of the mountain and burns the topsoil with its extreme heat. In such a changing landscape, even a small amount of rainfall causes a large amount of outflow, and quickly moves downhill, soil and rubble eroding, gathering in a rapidly moving mixture.
These phenomena are known as landslides or debris flow, depending on how many sediments, rocks, and wood are incorporated. These are very dangerous for both property and people, and risks may last for several years until the vegetation grows and the soil is recovered.
After a series of floods that caused a fatal and damage after the fire in the 1930s, South California was infrastructure to contain such a flow, specifically before the dangers of mud and rubble reached the densely populated area at the foot. A large investment was made on large dams and small rubble pools designed to trap. In the mountains. More than 150 rubble plates have been constructed throughout the Southern California, playing a role in the Santa Monica Mountains and the Sangabriel Mountains under the Sangabriel Mountains, which were burned down by the Parisase Mountains and Eaton Mountains.
However, this infrastructure does not provide absolute protection. Small rubble pools are easy to cross water.
The Thomas Mountain Fire, which occurred in the Santa Innes Mountains on the Ventura County and Santa Barbara County in December 2017, was the worst flood in California in the past 100 years due to the rainfall following another winter. Caused. The debris of water, mud, rock, bush, and trees occurred from the valley of the Santa Ines Mountains, moved several miles across the debris flow basin, destroyed a part of the town of Montesito, and blocked the expressway 101. 。 The flood killed 23 people and 23 people died. Destroyed 400 buildings.
In order to avoid such a tragedy, it is very important to maintain rubble pools, especially accumulated sediments, and ensure sufficient capacity in the next storm. Cleaning of rubble pools between storms is particularly difficult and expensive because the soil is saturated, but it may be particularly important. A recent study of the California University Urbine has shown that the accumulated impact of storms that occurs in a row may cause the debris flow basin to cross.
We were happy to see Governor Gavin New Sam, who had called for government agencies to prepare for the risk of landslides and debris flow. Removing debris from the ruins of the burnt is to minimize the amount of substances that can contribute to the stone flow, and cleaning the debris accumulation and flood waterways protects the local community of these structures. It helps to maximize your abilities. However, policy proppons also provide the funds necessary to repeatedly clean the flood control infrastructure throughout the year, quickly updated the flood hazard maps to accurately reflect the severity of burns in the entire basin. You must communicate your risks to residents and companies and prepare for quick evacuation in an emergency. It seems necessary.
The climate change has intensified the cycle of fire and floods in California, is at risk, and has a great pressure on the infrastructure designed to be considerably less climate and much less population. Just as the risk of wildfire is increasing, the risk of landslides and debris flow after the fire is urgently and serious. He is looking for an immediate preparation and the cooperation of the people to save his life and protect the neighboring areas.
Jeffrey Mount is a senior researcher at the California Policy Research Institute Water Policy Center. Brett Sanders is a professor of civil engineering, environmental engineering, urban planning, and public policy at the University of California University.
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