Analysis of potential hazard of debris flows under failure conditions of check dams
Affected by extreme rainfall,debris flow disasters are frequent and serious.The use of check dams and other meas-ures to prevent and control debris flows is one of the effective means to protect mountain towns.With time elapsing,some check dams have reached the designed service life,so the potential failure risks are increasing.To explore the potential hazards of debris flows with different frequencies under the potential failure of check dams,a study was conducted in Shaergou Gully in Jinchuan County,Sichuan Province.We used FLO-2D numerical simulation software to simulate the movement and accumulation charac-teristics of debris flows under three working conditions:no engineering measures,normal operation of check dam and failure of check dam.And the hazards of debris flow were zoned.The results showed that compared with natural conditions,the difference between the maximum accumulation depth of engineering failure case was small,and the average accumulation depth increased by 2.57%～5.77%;the maximum flow velocity and average flow velocity increased by 0.10%～35.98%and 1.95%～6.55%,re-spectively;therunoutdistancegot longer,and the volume of debris flow flushing out increased by3.14%～6.65%.Compared with no engineering measures and normal operation conditions of the check dams,the area of the high-risk area under the engi-neering failure condition increased by0.93%～3.39%and8.91%～17.93%,respectively;the accumulation range increased by 0.39%～0.83%and 11.50%～22.50%,respectively.If the check dams fail,it will produce a huge debris flow potential dan-ger,so the monitoring and early warning on aging check dams should be strengthened in extreme weather.The results can provide references for prevention and control of debris flow in the study area.
debris flowpotential hazardfailure of check damnumerical simulationShaergou Gully
国家科技期刊平台
NSTL
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