How to judge the level of mountain torrents?

The grade of mountain torrents is judged according to the severity and urgency.

The early warning level of flash flood rainfall intensity is divided into three levels (III, II and I). According to the severity and urgency of mountain torrents, the colors are yellow, orange and red in turn, and the warning signals of the three colors represent heavy, serious and particularly serious respectively.

1 and Ⅲ are yellow warning signals (the warning level is heavier). According to the rainfall forecast, there will be heavy rainfall within 24 hours, the rainfall intensity may approach or reach the critical rainfall, and the rainfall may continue.

It is predicted that serious mountain torrents may occur. At this point, the competent department should start the corresponding emergency procedures and enter the state of disaster prevention. Relevant departments should strengthen their duty and do a good job in tracking, forecasting and early warning of possible mountain torrents. Pay close attention to weather changes and changes in river water level and geological conditions at any time, and make preparations for transferring residents, staff and property threatened by disasters.

2. Grade I and Grade II are orange warning signals (the warning level is serious). According to the rainfall forecast, there will be heavy rainfall within 24 hours, and the rainfall intensity is 1~2 times of the critical rainfall intensity point (re

3. Level I is red warning signal (the warning level is particularly serious). It means that according to the rainfall forecast, there will be heavy rainfall within 24 hours, and the rainfall intensity is more than twice that of the critical rainfall intensity system (R & gt2× energy system), and the rainfall may last for a long time.

A particularly serious flash flood may occur within 24 hours. At this time, the competent department should start special emergency procedures and enter a state of special emergency disaster prevention. Relevant departments should do a good job in monitoring, forecasting, forecasting and early warning services for major mountain torrents, and start emergency rescue plans in time.

Extended data

To do a good job in the prevention and control of mountain torrents and achieve the work objectives, we must do two basic tasks in a down-to-earth manner.

The first is to rationally divide the areas affected by mountain torrents. According to the climatic, geological and geomorphological conditions in various places, on the basis of careful analysis of historical mountain torrents' hazards, it is the primary work of mountain torrents prevention and control to determine the areas prone to mountain torrents and be aware of them. On this basis, according to the possibility and harmfulness of mountain torrents, mountain torrents are generally divided into dangerous areas and warning areas.

Dangerous areas refer to areas where landslides, collapses and mudslides have occurred, and low-lying areas or beaches below the 20-year flood level on both sides of rivers; Warning area refers to the area where landslides, collapses and mudslides are very likely to occur under heavy rainfall, and the area between the 20-year flood level and the highest flood level on both sides of the river.

The second is to explore the law and scientifically determine the characteristic rainfall of disasters. Because mountain torrents are formed by rainfall, scientifically determining the characteristic rainfall caused by mountain torrents is the key basis for mountain torrents prevention and control, especially for making mountain torrents prevention and control plans. Generally, the early warning rainfall and dangerous rainfall can be determined according to the local underlying surface conditions and the formation and evolution process of historical mountain torrents.

Early warning rainfall refers to the rainfall when the rainfall reaches a certain characteristic value in a certain period of time. If the rainfall continues, mountain torrents may occur. Dangerous rainfall refers to the rainfall when the rainfall reaches a certain characteristic value in a certain period of time, that is, the rainfall when flash floods may occur.

The characteristic rainfall is generally 1 hour, 2 hours? Divide the rainfall period in 6 hours, and analyze and determine the corresponding characteristic rainfall. The specific division and determination should be selected according to the local actual situation.

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