Shallow layer landslide type valley debris flow early warning method

Abstract

The invention discloses a shallow landslide type valley debris flow early warning method, which belongs to the technical field of debris flow prevention and control engineering, and is characterized by comprising the following steps of: a, measuring a full watershed area A of debris flow without accumulation areas; b, measuring the percentage S0 of the sensitive slope area in the whole drainage basin area of the debris flow without the accumulation area and the longitudinal gradient J of the gully bed, and determining a debris flow topographic factor T; c, determining the annual average rainfall R0 of the debris flow channel in the monitoring area and the one-hour rainfall variation coefficient Cv of the debris flow channel, measuring the one-hour excitation rainfall It, determining the mother rock type of the soil, calculating the soil moisture content factor K, and determining the debris flow rainfall factor R; d, calculating a debris flow occurrence index P; and e, judging the occurrence of debris flow. The measurement and calculation result of the method is more in line with the debris flow formation mechanism, the debris flow early warning accuracy is improved, and the method has higher disaster prevention applicability.

Description

technical field [0001] The invention relates to the technical field of debris flow prevention and control engineering, in particular to a shallow landslide type valley debris flow early warning method. Background technique [0002] Shallow soil landslide is one of the most widely distributed landslides, with high frequency of outbreaks, and one of the most harmful geological disasters. Shallow surface soil landslides refer to a type of landslides that occur on the slopes of loose and unconsolidated clay or sandy soils. Its material composition is generally the weathering product of bedrock, and the accumulation thickness is usually less than 5 meters. Due to the loose sliding mass, such slopes are vulnerable to the periodic influence of atmospheric precipitation and reservoir water level, and their stability is poor. Such landslides are very likely to be transformed into debris flows if they encounter sufficient water sources and sufficient sliding surfaces during the slid...

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Problems solved by technology

[0011] The valley debris flow early warning method disclosed in this patent document needs the previous rainfall as a part of the rainfall factor, and the definition of the early rainfall is often not easy to accurately express the role of rainfall in the formation of shallow landslides and later mountain torrents and the final debris flow, resulting in debris flow The accuracy of early warning is reduced, and the applicability of disaster prevention is not good

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