TO THE QUESTION ABOUT CALCULATION OF DEBRIS-FLOWS DISCHARGE AND HIGHER DEBRIS-FLOWS HORIZONS OF 1% AND 5% REPEATABILITY

Section
Scientific discussions
  • Nikolay A. Kazakov Special Research Bureau for Automation of Marine Researches of the Far Eastern Branch of Russian Academy of Sciences, Yuzhno-Sakhalinsk, Russia Research Center «Geodinamics», Yuzhno-Sakhalinsk, Russia
Keywords: debris-flows, debris-flows frequency, debris-flows discharge, potential debris-flow massif, debris-flow process, higher debris-flow level

When performing engineering surveys, it is recommended to calculate the discharge and values of 1% and 5% of the debris-flows frequency. This frequency is calculated as 1% and 5% flow frequency of water discharge and flood water levels. Such calculations, in turn, are performed on the basis of calculations of 1% and 5% of the precipitation frequency falling. However, the debris-flows frequency does not always correspond to the water flow frequency. This is because the dominant role of the debris-flows process is played by geological factors of debris-flows formation. The occurrence of a debris-flow is preceded by a period of preparation of loose-rocks in debris-flows site (accumulation of a critical volume of loose-rocks and its achievement of a certain degree of moisture of loose-rocks) and the flood that caused the formation of a debris-flows in its parameters may be less than the flood. Equal in repeatability to with the corresponding accumulation of loose-rocks in debris-flows basin and strong soil moisture in potential debris-flows massif, the formation of debris-flows is caused by relatively small precipitation. For these reasons, the calculation of the frequency of debris-flows volumes and discharge on the basis of hydrological calculations only is unacceptable. When determining the frequency of the debris-flows maximum volumes and discharge, it is cannot to operate mechanically to compare the frequency of debris-flows and water discharge. There are no methods for calculating on the basis of geological factors the frequency of those parameters of debris-flow that determine the it’s volume. When designing objects and structures or when solving scientific problems, the use of the characteristic "5%, 1% of the debris-flows frequency" is unacceptable, since it leads to an unjustified underestimation of the degree of debris-flows hazard and to a wrong idea about debris-flows processes. All of the above fully applies to the provision of avalanches of large volumes.

Nikolay A. Kazakov,
Special Research Bureau for Automation of Marine Researches of the Far Eastern Branch of Russian Academy of Sciences, Yuzhno-Sakhalinsk, Russia Research Center «Geodinamics», Yuzhno-Sakhalinsk, Russia

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Fleishman S.M. Seli. [Debris flow]. Leningrad, Gidrome-teoizdat, 1978. 312 p. (In Russian).

Kazakov N.A. Geologicheskie i landshaftnye kriterii ocenki lavinnoj i selevoj opasnosti pri stroitel'stve linejnyh sooruzhenij (na primere o. Sahalin). Avtoref. diss. kand. geol-min. najuk. [Geological and landscape criteria for assessing avalanche and debris flow hazard during the construction of linear structures (on the example of Sa-khalin Island). Ph. D. (geological and mineralogical) Thesis]. Yuzhno-Sahalinsk, 2000. 36 p. (In Russian).

Vinogradov Yu.B. Etyudy o selevykh potokakh [Etudes about mud stream]. Leningrad, Gidrometeoizdat Publ., 1980. 144 p. (in Russian).


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Published
2019-12-16
How to Cite
Nikolay A. Kazakov. (2019). TO THE QUESTION ABOUT CALCULATION OF DEBRIS-FLOWS DISCHARGE AND HIGHER DEBRIS-FLOWS HORIZONS OF 1% AND 5% REPEATABILITY. Hydrosphere. Hazard Processes and Phenomena, 1(2), 296-301. https://doi.org/10.34753/HS.2019.1.2.007

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