A rapid identification method for hidden danger points of debris flow in strong earthquake area

Abstract

The invention discloses a meizoseismal area debris flow hidden risk point quick recognizing method. According to the method, drainage basins are divided according to a meizoseismal area vector topographic map to obtain areas of the drainage basins, the total area and the total volume of critical loose material sources which are needed by debris flows of each drainage basin are obtained through calculation, then the total area and the total volume of new loose material sources in drainage basins to be recognized are obtained through remote-sensing images and calculation, and finally the total area and the total volume of the new loose material sources in the drainage basins to be recognized are compared with the total area and the total volume of the critical loose material sources which are needed by the debris flows of the drainage basins so as to judge whether the drainage basins to be recognized are new debris flow hidden risk points or not after earthquakes. Compared with the prior art, the method enables the new loose solid material sources after the earthquakes to serve as the only debris flow recognition indicator, it is distinguished that a judging threshold value is a variable related to the areas of the drainage basins, supporting data are easy to obtain, the recognition precision is high, the debris flow hidden risk points of the meizoseismal area can be recognized reasonably and quickly, and reference is provided for site selection of post-disaster reconstruction in the meizoseismal area.

Description

technical field [0001] The invention relates to a method for quickly identifying hidden danger points of debris flow in a strong earthquake area. Background technique [0002] The time-lag persistence effect of disaster activities such as collapses, landslides, and debris flows in strong earthquake areas is very obvious and will last for more than 20 years. It has been five years since the magnitude 8.0 Wenchuan Earthquake, during which there have been six rainy seasons. The torrential rains after the earthquake have repeatedly induced mass mudslides, causing a large number of casualties. For example, the Beichuan debris flow on September 24, 2008, the Zhouqu debris flow on August 7, 2010, the Wenjiagou debris flow in Qingping Township, Mianzhu on August 13, 2010, the Dujiangyan Longchi debris flow on August 13, 2010, The Yingxiu debris flow on August 14, 2010, and the Yinchanggou debris flow on August 18, 2012; these debris flow disaster events show that debris flow activi...

AI Technical Summary

Problems solved by technology

This method belongs to the single-factor evaluation method and avoids the controversy over the weight values ​​of multiple factors. However, this method only considers the source of loose solid matter per unit area, and ignores the impact of new loose solid matter on the formation of debris flows after the earthquake. It plays an important role, and when the total amount of loose solid matter cannot be known, it is difficult to be used to judge the hidden danger of debris flow; The method cannot be applied to all debris flow ditches, and it is easy to misjudge some mountain torrent ditches as debris flow ditches

The above two shortcomings make this method unable to meet the needs of rapid identification of debris flow hidden danger points in strong earthquake areas

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