Back calculation and hazard prediction of a debris flow in Wenchuan meizoseismal area, China

2021 ◽  
Vol 80 (4) ◽  
pp. 3457-3474 ◽  
Author(s):  
Bo Liu ◽  
Xiewen Hu ◽  
Guotao Ma ◽  
Kun He ◽  
Mingyan Wu ◽  
...  
Keyword(s):  
Debris Flow ◽  
Back Calculation ◽  
Meizoseismal Area

scholarly journals On the use of the calibration-based approach for debris-flow forward-analyses

2010 ◽  
Vol 10 (5) ◽  
pp. 1009-1019 ◽  
Author(s):  
M. Pirulli
Keyword(s):  
Debris Flow ◽  
Debris Flows ◽  
Single Phase ◽  
Back Analysis ◽  
Numerical Approach ◽  
Rheological Parameters ◽  
Trial And Error ◽  
Back Calculation ◽  
Selection Of ◽  
Volume Size

Abstract. In the present paper the problem of modeling the propagation of potential debris flows is tackled resorting to a numerical approach. In particular, numerical analyses are carried out with the RASH3D code, based on a single-phase depth-averaged continuum mechanics approach. Since each numerical analysis requires the selection of a rheology and the setting of the rheological input parameters, a calibration-based approach, where the rheological parameters are constrained by systematic adjustment during trial-and-error back-analysis of full-scale events, has been assumed. The back-analysis of a 1000 m3 debris flow, located at Tate's Cairn, Hong Kong, and the forward-analysis of a 10 000 m3 potential debris flow, located in the same basin have been used to investigate the transferability of back-calculated rheological parameters from one case to another. Three different rheologies have been tested: Frictional, Voellmy and Quadratic. From obtained results it emerges that 1) the back-calculation of a past event with different rheologies can help in selecting the rheology that better reproduces the runout of the analysed event and, on the basis of that selection, can give some indication about the dynamics of the investigated flow, 2) the use of back-calculated parameters for forward purposes requires that past and potential events have similar characteristics, some of which are a function of the assumed rheology. Among tested rheologies, it is observed that the Quadratic rheology is more influenced by volume size than Frictional and Voellmy rheologies and consequently its application requires that events are also similar in volume.

A hands-on approach to estimate debris flow velocity for rational mitigation of debris hazard

2018 ◽  
Vol 55 (7) ◽  
pp. 941-955 ◽  
Author(s):  
Md. Aftabur Rahman ◽  
Kazuo Konagai
Keyword(s):  
Debris Flow ◽  
Flow Velocity ◽  
Three Dimensional ◽  
Iterative Approach ◽  
Bend Radius ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Key Issues ◽  
Back Calculation

Rational estimation of debris flow velocity is one of the key issues in debris hazard mitigation. Among the various procedures, back-calculation of debris flow velocity is one of the most frequently used approaches. Back-calculation includes determination of super-elevations and channel properties, and velocities are calculated using the forced vortex equation. Super-elevation and bend radius are biasing parameters in the back-calculation scheme. Therefore, an iterative approach based on simplified assumptions is developed to avoid the direct and subjective determination of bend radius. Besides, as only the highest mud prints are visible after the disaster, this misreads the actual super-elevation. To seek better ways to fix this anomaly, a series of three-dimensional numerical curved flume tests using smoothed particle hydrodynamics are carried out. Estimated velocities from highest flow marks underestimate the actual velocities near the source, while they converge on the actual velocities as the distance to source increases. A best-fit line is then proposed to adjust the mud-marks-derived velocities to the real velocities. The assumption taken during development of the iterative approach for determining bend radii is also justified from the numerical simulations. The law of similarity allows application of these findings to real debris flow disasters. Thus, two real debris flow disasters in Japan are examined for validation of the developed procedure and adjusted velocities are proven to be consistent with verbal evidences and previous analyses.

scholarly journals Analytic Back Calculation of Debris Flow Damage Incurred to a Masonry Building: The Case of Scaletta Zanclea 2009 Event

2016 ◽  
Vol 7 ◽  
pp. 04007
Author(s):  
Hossein Soleimankhani ◽  
Stefano Carozza ◽  
Giuseppe T. Aronica ◽  
Fatemeh Jalayer ◽  
Antonino Recupero
Keyword(s):  
Debris Flow ◽  
Masonry Building ◽  
Back Calculation

Back-Calculation Method of Subgrade Modulus Based on Traffic Speed Deflectometer

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Guoshuai Zang ◽  
Haizhu Lu ◽  
Guanglai Jin ◽  
Zhixiang Zhang
Keyword(s):  
Calculation Method ◽  
Back Calculation ◽  
Subgrade Modulus ◽  
Traffic Speed

GROWTH OF PIKE-PERCH SANDER LUCIOPERCA (L., 1758) (PERCIDAE) IN RESERVOIRS OF K. SATPAYEV’S CHANNEL

2018 ◽  
pp. 59-68
Author(s):  
Saule Zhangirovna Asylbekova ◽  
Kuanysh Baibulatovich Isbekov ◽  
Vladimir Nickolaevich Krainyuk
Keyword(s):  
Growth Rates ◽  
Growth Dynamics ◽  
High Growth ◽  
Water Bodies ◽  
Volga River ◽  
Trophic Resources ◽  
Pike Perch ◽  
The Amur River ◽  
Back Calculation ◽  
Abiotic And Biotic Factors

Pike-perch is an invader for the water basins of Central Kazakhstan. These species have stable self-reproductive populations in the regional waters. Back calculation method was used to investigate pike-perch growth rates in reservoirs of K. Satpayev’s channel. For comparison, the data from the other water bodies (Vyacheslavsky and Sherubay-Nurinsky water reservoirs) were used, as well as literature data. Pike-perch species from the investigated waters don’t show high growth rates. The populations from the reservoirs of K. Satpayev’s channel have quite similar growth rates with populations from the Amur river, from a number of reservoirs in the Volga river basin and from the reservoir in Spain. Sexual differences in growth have not been observed. Evaluating possible influence of various abiotic and biotic factors on the growth rate of pike-perch in the reservoirs of K. Satpayev’s channel was carried out. It has been stated that the availability of trophic resources cannot play a key role in growth dynamics because of their high abundance. Morphology of water bodies also does not play a role, as well as chromaticity, turbidity and other optical water indicators. It can be supposed that the main factor influencing growth of pike perch is the habitat’s temperature. This factor hardly ever approaches optimal values for the species in reservoirs of K. Satpaev’s channel. The possible influence of fishing selectivity on pike-perch growth rates was also evaluated. Currently, there has been imposed a moratorium on pike-perch catch. However, pike-perch is found in by-catches and in catches of amateur fishermen. It should be said that such seizures have an insignificant role in the dynamics of growth rates.

Sign in / Sign up

Export Citation Format

Share Document