Mudflow is a turbulent stream in which there is a large concentration of rock fragments, stones and mineral particles. Their number can exceed half the volume of all water present in it. Natural disaster - mudflow - suddenly appears in the basins of small mountain rivers. Most often, the main cause of its occurrence is a sharp melting of snow or intense heavy rainfall.
General information
The consistency of the flow is an intermediate substance between solid and liquid mass. Mudflow is a phenomenon that is relatively short-lived and lasts no more than three hours. Predominantly occurs in small streams, the length of which does not exceed 30 kilometers.
Features
The speed of movement of such streams is in the range from 2 to 6 meters per second. This is the reason for their destructive action. A mudflow is a stream that creates deep channels along its path. They usually contain small streams or are completely dry. Components of whichconsists of a stream, accumulate on the plains in front of the mountains. Mudflow is characterized by movement in the form of a water shaft of its frontal part. Most often there is a row, which consists of shafts alternating each other. When mudslides come down, the consequences are almost always strong changes in the shape of the channel.
Reasons for appearance
Mudflow is a violent natural phenomenon. The flow may be due to rapid melting of glaciers, seasonal snow masses, or prolonged and intense heavy rainfall. Also, the cause of occurrence can be the ingress of a huge number of loose-clastic objects into the channel. Deforestation in mountainous areas is one of the main factors in the appearance of a turbulent stream. Trees play an important role in preventing mudflows, as their roots hold the top layer of soil. In dry logs with a large slope and in the basins of small mountain rivers, destructive flows rarely appear. Mudflows can be classified. There are landslide, breakthrough and erosion types of the origin of this phenomenon.
Focuses
Potential places for the occurrence of a flow are a basin or a section of the channel, if a large amount of loose clastic material has accumulated in them. The risk group also includes territories where all conditions for its accumulation are created, and certain areas of flooding. These foci have their own classification. There are potholes, incisions and places of dispersed formation of flows. The area of dispersed mudflow formation is consideredsteep exposed areas in which a large amount of strongly destroyed rocks has accumulated. Such a focus has a branched and dense network of furrows. The process of formation of microflows and the formation of weathering products take place directly in them. Then all these elements are combined into a single channel.
Debris pothole
This phenomenon is a linear formation that cuts through forested, turfed and rocky slopes. They are usually composed of thin weathering crust. Such potholes are characterized by small depth and length. Its bottom angle is greater than 15 degrees.
Incision
This phenomenon is a powerful formation that developed in the array of ancient moraine deposits. Predominantly included in the general part of the sharp bends of the slope. In addition, such incisions often occur on such types of relief as: landslide, volcanogenic, landslide and accumulative. The size of mudflow cuts significantly exceeds potholes. Their longitudinal profiles also differ. At cuts, they have smoother outlines than at potholes. The maximum depth of the first can exceed 100 meters. The catchment area of this type can reach 60 kilometers, while the volume of soil removed by one flow is 6 million cubic meters.
Methods of protection
sel (the photo of the stream is presented in the article) has a huge destructive effect. To combat them, special structures are being built and measures are being taken to consolidate the vegetation and soil cover. Choosing a protection methodis based on the definition of the boundaries of the mudflow basin. Ideally, preventive measures should stop and weaken its action at the very beginning of the flow. Afforestation on the territory of dangerous areas is considered the most radical method. This technique is able to divide the total flow into separate jets, reduce the total mass of water and adjust the flow. In the danger zone, it is necessary to increase the stability of the slopes, as well as to intercept and divert mudflows with the help of earthen ramparts and upland ditches. The most efficient use of dams in the channels. They are structures made of concrete and stone, the task of which is to delay part of the solid materials of the flow. The dams are designed to direct the mudflow to a less prone to rupture shore. Also, an effective way of protection is the construction of guide dams. They are able to direct the flow in the right direction and significantly weaken its impact.
