Curious about events in the country and the world, viewing news feeds, we often see pictures, videos of natural disasters caused by mudflows.Catastrophes in the world is growing: global warming is to blame if, maybe, human activity, or our planet passes through certain "catastrophic" periods in its history for some other reasons, but the effects of disasters are always the same.Frightened people, refugees, lost homes and possessions, killed cattle and disfigured landscapes, only yesterday seemed a fairy tale, and today resemble the picture of the films on the theme of the apocalypse.So how it is formed mudflow that you can take to avoid death and destruction, or to make the consequences of the disaster minimum?
What is rural in nature?
word has Arab roots.The name means "torrent".Muddy mud weight, rushing with great speed, sowing death, swept away everything in its path - buildings, natural landscapes, along with all their inhabitants, from animals to humans.The mudflow contains many solids: large and small stones, rock particles, which, incidentally, can be more than half of the total weight.Many villages in the mountains there a long time, have a long history, happily avoiding natural disasters, but in nature there is something unusual, extraordinary (Stormy and prolonged rainfall, rapid warming, combined with a particularly rapid snowmelt, glacier in the mountains) - and the looming disaster.Lasts elements revelry usually short-lived, for several hours, but this is more than sufficient to cause irreparable within a few years the damage to nature and people, as, for example, it was once came down in 2013, mudslide in Georgia.Then, because of the accident was completely paralyzed traffic.Suffice it also brought serious damage and debris flows in Taba (it describe below).
Features
mudflow has a very high speed.Mud weight often appear suddenly, without allowing enough to take operational measures to protect people and nature.Mudflow comprising hard rock is carried at a rate of 2-4 to 4-6 meters per second.As a result, gathering the landscape can take very different outlines: the stones in just a few hours break through new channels of rivers and streams, a layer of debris and dirt covers the fertile piedmont plains used for growing crops and grazing.Blooming Valley becomes dead and unfit to live and work.The mudflow could go in several stages, with each new wave of further increasing the size of the disaster.
What are the causes of this natural phenomenon?
- Stormy and prolonged rainfall.If the case of local "world flood", they looked exactly the way from the mountains to the converging mudflows, perishing people and buildings.
- sharp warming having seasonal or off-season, which can cause melting of snow and glaciers.Located beneath the glacier village is always an increased risk.
- In areas with a large bias in the river bed may collapse a significant portion of the soil with debris and thus block the waterway, send it to another, unexpected way, trigger avalanches.
What can serve as additional factors, provoking a catastrophe?
tree roots well strengthen the upper layers of the soil, preventing it from moving, even when exposed to heavy rain flows or weathering, because reckless felling of forest plantations - one of the main factors that increase the threat of natural disasters of this kind.They sat on the causes of divided into three groups: as a result of erosion and landslip breakthrough.
Where are the hotbeds of potentially dangerous?
danger, in the long term, can be any part of a mountain river, which accumulates easily moved by water currents soil, rock.It can be incisions or potholes, as well as pockets dispersed mudflow.
Classification foci
potholes - education on the slopes, cut through the rock, turf and other surfaces, they are small in length and depth, and does not pose a danger, until the stream, which can lead to the movement of rocks.Incision - based education moraine deposits associated with sharp elevation changes.They are very ancient origin.Young incisions may occur as a result of recent volcanic activity, and as a result of landslides, mudslides.Potholes larger incision depth and length.Dispersed mudflow may occur on steep mountain areas where concentrated a lot of debris of rocks, weathering products.Such surfaces, large in size, there may be a result of the recent earthquake, active tectonic processes.The surface of these centers is covered with grooves, which gradually accumulate debris foods that can, under certain conditions, to merge into a single channel and unleash its power on the facilities located on the slopes.
How to prevent avalanches?
Since one of the main reasons for gathering water and debris flows is the loss of forest plantations, the problem may solve the plantations.Engineering (ditches, embankments, tracing), diverting potentially damaging currents can also give considerable positive results.Installation of dams on the road dangerous riverbeds and streams rushing of the delay from the slope of the mass, which is slightly weaken its destructive potential.Any other structures (pits, pools, dams) also reduce the risk of disaster, it is important to strengthen shorelines, prevent them from further erosion, especially if located on the shores of the building.From the passage of mudflows often suffers road surface, it is advisable for the protection of which to construct the trays (stone or concrete) over- or under it in the areas of high risk.
most famous avalanches and their effects, documented historical science
- From 17 to 18 August 1891 in Tyrol, in the Austrian Alps, descended the large rural: the wave reached a height of 18 meters, turned out to be a huge area covered with a thick layer of debris flow mass.
- March 1, 1938 hit Los Angeles, killing more than 200 people.
- July 8, 1921 Stream hit Alma-Ata (now the Alma-Ata), several waves brought to the city of 3.5 million square meters.m solid.
- In 1970 there was an accident in Peru, as a result of mudflow activity have killed more than 60,000 people and 800,000 refugees, lost their property, were left without a roof over their head.
Holocaust today
- January 24th 2013 mudflow came in Sochi.He was stopped as a result of timely and competently carried out works on the construction of fortifications of the city administration.
- 8 May 2014 on the border of Egypt and Israel as a result of rains were flooded several hotels.Then came mudslide in Taba, hit the road.The consequences were eliminated within a week.
- May 17th 2014 mudflow came down in Georgia, near the settlement Gveleti.The flow of the river Terek blocked.There was a section of road is closed, "Vladikavkaz-Lars", arose as a direct threat of flooding several villages.The trouble has passed - water "found" a temporary channel, and its level did not exceed dangerous levels.When the mudflow came down to Larsen, the necessary measures have been taken in time, the local population immediately evacuated to a safe area.
