Gully debris flow early warning method based on soil moisture content

Abstract

The invention discloses a valley debris flow early warning method based on soil moisture content, which belongs to the technical field of debris flow prevention and control engineering, and is characterized by comprising the following steps: S1, determining basic parameters of a potential debris flow basin through Google Earth or a topographic map; s2, early-stage rainfall of the position where the debris flow basin formation area is located and rainfall 10 minutes before excitation are monitored or forecasted in real time; s3, investigating the average width of channels in the debris flow basin forming area and the particle size of particles in the debris flow basin forming area; s4, calculating a topographic factor T of the debris flow basin; s5, calculating a debris flow basin geological factor G; s6, calculating a rainfall factor R inducing debris flow; s7, judging the occurrence of debris flow; according to the method, starting from the starting principle of the gully debris flow, the soil moisture content is directly adopted as a main precondition for exciting debris flow rainfall, the rainfall contribution can be calculated more accurately, and thus the debris flow can be early warned more accurately.

Description

technical field [0001] The invention relates to the technical field of debris flow prevention and control engineering, in particular to a method for early warning of debris flow in valleys based on soil moisture content. Background technique [0002] Debris flow is a natural disaster that occurs in mountainous areas. Water is an important condition for the formation of debris flow. The main factors of water source conditions in rainfall debris flow are rainfall intensity, rainfall, rainfall frequency and temperature. Due to the short-duration heavy rainfall, the rainfall is stronger than the soil infiltration capacity to form hyperosmotic runoff. After the hyperosmosis runoff converges on the slope surface, it gathers in the ditch to form flash floods, and the flood scours the source in the scraper ditch and finally forms a debris flow. For the ditch bed-initiated gully debris flow, rainfall is the key parameter to stimulate debris flow. The formation mechanism of the gul...

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Problems solved by technology

[0005] The rainfall segmentation method disclosed in this patent document for the prediction of trench-bed start-up debris flow determines the calculation method of the rainfall process through the rainfall intensity and rainfall interval time, and then calculates Previous rainfall is an indirect method, that is, through the segmentation of rainfall, it assumes the influence of rainfall conditions on the subsequent rainfall; however, this method no longer considers the influence of previous rainfall after the rainfall has stopped for 6 hours or 12 hours In fact, if the rain stops for 6 hours or 12 hours, the soil will still retain some water, that is, the previous rainfall still has effects and influences, so it is possible to underestimate the previous rainfall, resulting in missed reports and affecting the accuracy of debris flow early warning. Spend

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