A method for early warning of overflow water level of glacial lake outburst and its application

Abstract

The invention discloses an overflow water level warning method for glacial lake outburst, which comprises the following steps: (a) the thickness T of the top of an ice trace dam, the width b of the outburst mouth, the average width w0 of a glacial lake, the length-to-width ratio c of the glacial lake, the average slope Beta of the shore slope of the glacial lake before outburst, and the characteristic particle size d of incipient sediment are surveyed; (b) the critical overflow water depth H of glacial lake outburst is calculated; and (c) the water level of the glacial lake above the overflowmouth rises suddenly for more than 30s, and when HCr<0.6H, there is very small probability that the glacial lake bursts; when 0.6H<=HCr<0.8H, there is small probability that the glacial lake bursts; when 0.8H<=HCr<H, there is medium probability that the glacial lake bursts; and when the HCr>=H, there is large probability that the glacial lake bursts. The method fully considers the factors influencing the critical overflow water depth of glacial lake outburst. The calculated result is more in line with the actual situation. The accuracy of warning is high. The method is of higher applicability.

Description

technical field [0001] The invention relates to the technical field of water conservancy engineering, in particular to an overflow water level early warning method for a glacial lake outburst and its application. Background technique [0002] Glacial lake outburst is a natural phenomenon that occurs in the distribution area of ​​alpine glaciers. The main cause of glacial lake outbursts is the flooding type of ice-slides or ice avalanches into the lake. Ice landslides or ice avalanches into the lake cause the water level to rise and form an overflow. When the flow rate of the overflow water head is greater than the starting flow rate of the moraine and the rate of water level drop is lower than the rate of scouring downcut, it will lead to collapse. Therefore, the study of the critical hydrological conditions of the overflow-type outburst of the moraine lake is the basis for predicting the disaster of the outburst of the glacial lake. [0003] At present, domestic and forei...

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Problems solved by technology

[0005] The glacial lake outburst early warning method disclosed in this patent document studies the internal mechanism of the glacial lake outburst occurrence degree by studying temperature factors and topographical factors, and establishes a glacial lake outburst early warning and forecast model; however, this method only considers glacier collapse, Furthermore, it may cause the collapse of the glacial lake. Whether the ice avalanche can reach the glacial lake has not been considered; whether the volume of the ice avalanche is large enough and whether it can cause the water level of the glacial lake to rise to a sufficient height. The accuracy of early warning is low and the applicability is poor

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