Study The Relationship Between Frequency Of Debris Flows And The Lithology In Channels Of Debris Flows

The area of our country of mountainous region is big , geological ambient conditions is complex, geological hazards type is complete, growth measures big, it is broad to divide into cloth cover, serious threat the life property safety of people. Debris flow as the one of the type of geological hazards is a kind of course and phenomenon that burst natural calamity changes , is to be situated between go down , collapse wait for piece body sport and carry a series of continuously floating phenomenon between sand current sport, have frequently the course that forms complex break out suddenly , on-coming force violent last short destroy power maximum characteristic, as the economic construction of mountain area causes maximum damage. The debris flow calamity of our country is some few debris flow campaign on world most strong , calamity the most serious national one. Therefore, people pay attention to hope to make people avoid its harm through foreseeing forecast for the research work of debris flow calamity in recent years more. And what break out frequency for debris flow foresee always since is difficulty , this paper only breaks out frequency under so a background for debris flow related research work.The broken out frequency of debris flow can be divided into the rate of high frequency, the rate of intermediate frequency and low frequency are led debris flow 3 kinds, the rate of high frequency and the rate of intermediate frequency of the debris flow are easy to be discovered by people, do not be easy to form calamity, and the rate of low frequency of the debris flow occurs frequency low, is easy by people place overlooks , so under special condition after breaking out debris flow, often form maximum calamity. This paper is with the purpose of foreseeing debris flow to break out frequency , supposes rock this single factor and the correlation that breaks out frequency: The lower frequency, the more solid rock. On this foundation, first, select the SiChuan western area of 17 debris flow ditchs for the study, through looking up document, determine each ditch s break out frequency, then, focal point carries out the inquiry of open country, investigate in detail the rock that each ditchs forms district or the accumulation district pellet of "Cu Hua Ceng" etc., through analysing for the data of 17 ditchs inquiry, combination rock solid level grades , we reach the feature that debris flow accumulation district rock composition feature can represent to form district, and pass through the relation of analysis frequency and rock, since determining the nature and on ration, determine the reasonability of assupmtion, get rock hardness coefficient F≤7.0, form the rate debris flow of high frequency , hardness coefficient F≥10.0, form the rate debris flow of low frequency , hardness coefficient 7.0 < F < 10.0, form the rate debris flow of intermediate frequency. Analyse through verifying , debris flow is broken out the correlation conclusion of frequency and rock single ditch break out frequency forecast on accuracy rate to reach 74.36%, on regional forecast, have fitness for purpose more. Fast break out frequency for debris flow to foresee , go on through field investigation of geological maps and compared the situation, think that two is suitable basically, therefore combination geological picture is analysed for studying the rock composition in valley can fast, rough inference single ditch or regional last debris flow break out frequency.