scholarly journals Interactive comment on “Assessment of relative importance of debris flow disaster risk affecting factors based on meta-analysis – cases study of northwest and southwest China” by Yuzheng Wang et al.

2020 ◽  
Author(s):  
Anonymous
Keyword(s):  
Debris Flow ◽  
Southwest China ◽  
Meta Analysis ◽  
Disaster Risk ◽  
Relative Importance ◽  
Affecting Factors ◽  
Cases Study ◽  
Debris Flow Disaster

scholarly journals Assessment of relative importance of debris flow disaster risk affecting factors based on meta-analysis – cases study of northwest and southwest China

2020 ◽  
Author(s):  
Yuzheng Wang ◽  
Lei Nie ◽  
Min Zhang ◽  
Hong Wang ◽  
Yan Xu ◽  
...  
Keyword(s):  
Risk Factors ◽  
Debris Flow ◽  
Southwest China ◽  
Meta Analysis ◽  
Geological Structure ◽  
Daily Maximum ◽  
Relative Importance ◽  
Maximum Rainfall ◽  
Factors Affecting ◽  
Geological Conditions

Abstract. Debris flow is a type of special torrent containing numerous solid materials. It is characterized by sudden outbreak, short duration, and strong destructive force. The occurrence of debris flow is often affected by hydrogeological and geological conditions, including basin area, main ditch length, relative height difference, slope, bed bending coefficient, daily maximum rainfall and so on. With many types of factors affecting debris flow, no reliable basis for selecting factors to evaluate debris flow risk has been established. Therefore, to study the factors affecting debris flow, exploring a reliable method for assessing the relative importance of such factors is an important endeavor in debris flow prevention and control work. In this research, debris flow risk assessment was combined with meta-analysis to analyze quantitatively the relative importance of risk factors of debris flow in northwest and southwest China. Results show that debris flow in northwest China is mainly affected by topography and geological structure. Rainfall plays an important role in stimulating debris flow in this area. For debris flow in southwest China, topography, geological structure, and rainfall conditions all have considerable influence. Meta-analysis can provide a basis for the selection of risk factors of debris flow and has certain reliability.

scholarly journals Assessment of Debris Flow Risk Factors Based on Meta-Analysis—Cases Study of Northwest and Southwest China

2020 ◽  
Vol 12 (17) ◽  
pp. 6841
Author(s):  
Yuzheng Wang ◽  
Lei Nie ◽  
Min Zhang ◽  
Hong Wang ◽  
Yan Xu ◽  
...  
Keyword(s):  
Risk Factors ◽  
Risk Assessment ◽  
Debris Flow ◽  
Southwest China ◽  
Meta Analysis ◽  
Main Channel ◽  
Relative Importance ◽  
Factors Affecting ◽  
Longitudinal Slope ◽  
Selection Of

Debris flow is a type of special torrent containing numerous solid materials. With many types of factors affecting debris flow, there is no reliable basis for the selection of risk factors for debris flow risk assessment. Therefore, to study the factors affecting debris flow, exploring a reliable method for assessing the relative importance of these factors is a significant endeavor in debris flow prevention and control work. In this research, debris flow risk assessment was combined with meta-analysis to analyze quantitatively the relative importance of risk factors of debris flow in northwest and southwest China. The final relative importance of each factor in northwest China is as follows, maximum relative height difference > slope of main channel > maximum daily precipitation > ratio of longitudinal slope > drainage area > length of main channel. In addition, in southwest China, maximum relative height difference > maximum daily precipitation > slope of main channel > ratio of longitudinal slope > length of main channel > drainage area. The meta-analysis results were accurate, which can provide a reliable basis for the selection of debris flow risk factors in debris flow risk assessment. Furthermore, it provides strong support for the application of meta-analysis in risk assessment of other geological hazards.

scholarly journals New insights into the delayed initiation of a debris flow in southwest China

2021 ◽  
Author(s):  
Taixin Peng ◽  
N. Sh. Chen ◽  
Guisheng Hu ◽  
Shufeng Tian ◽  
Zheng Han ◽  
...  
Keyword(s):  
Debris Flow ◽  
Southwest China ◽  
Theoretical Calculations ◽  
Low Frequency ◽  
Early Warning Systems ◽  
Warning Systems ◽  
Field Investigations ◽  
Delayed Initiation ◽  
Landslide Process ◽  
Debris Flow Disaster

Abstract On 6 July 2020, 3 h 40 min after rainfall stopped, a delayed debris-flow disaster occurred due to colluvium deposits in a hollow region (CDH) in the Chenghuangmiao gully, Sichuan Province, China, which resulted in 4 deaths and 27 injuries. This study explores the initiation process of the delayed debris flow and the cause for the delay. Field investigations, catchment geometry interpretation, laboratory tests, theoretical calculations, and fluid-solid coupling numerical simulation were performed to obtain landslide parameters and understand the mechanisms of the event. Results show: (1) The event was a giant low-frequency viscous debris flow. (2) Its initiation was caused by the delayed landslide process under the influence of back-end confluence. (3) The debris-flow discharge in the main gully increased over 19.5 min. (4) The seepage process inside the CDH continued for 3 h 20 min after the rainfall stopped before its pore pressure and reduction in strength was sufficient to initiate the debris flow. This research provides new insights on delayed debris-flow disasters; it is a reference for improving disaster management systems, especially monitoring and early warning systems, thereby avoiding future casualties.

The Calculating Method of Erosion Depth of Viscous Debris Flow

2012 ◽  
Vol 204-208 ◽  
pp. 3441-3444
Author(s):  
Yong You ◽  
Yan Bo Zhao ◽  
Jin Feng Liu
Keyword(s):  
Debris Flow ◽  
Good Method ◽  
Gully Erosion ◽  
Affecting Factors ◽  
Erosion Depth ◽  
Calculating Method ◽  
Viscous Debris Flow ◽  
Bed Erosion ◽  
Debris Flow Disaster ◽  
Theoretical Mechanics

Gully erosion depth is one of the most important parameters for the assessment and prevention of debris flows. So far, there is no good method for calculating the gully bed erosion depth of viscous debris flow. This paper discussed the calculation method of erosion depth of viscous debris flow based on theoretical deduction. The formula for calculating the erosion depth was constructed based on deduction from the viewpoint of theoretical mechanics. Then, the affecting factors of gully erosion were discussed. This method can be used to calculate the erosion depth for viscous debris flow under different frequencies and provide a better evaluation and prevention tool for mitigating debris flow disaster.

LEARNING TO ROLL WITH THE ONE-TWO PUNCH OF FIRE AND DEBRIS FLOW: LESSONS LEARNED FROM THE JANUARY 2018 DEBRIS-FLOW DISASTER IN MONTECITO, CA

2018 ◽  
Author(s):  
Jason W. Kean ◽  
◽  
Dennis M. Staley ◽  
Jeremy T. Lancaster ◽  
Francis K. Rengers ◽  
...  
Keyword(s):  
Debris Flow ◽  
Lessons Learned ◽  
The One ◽  
Debris Flow Disaster

scholarly journals Assessing the relationship between pregravid body mass index and risk of adverse maternal pregnancy and neonatal outcomes: prospective data in Southwest China

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yue Chen ◽  
Ke Wan ◽  
Yunhui Gong ◽  
Xiao Zhang ◽  
Yi Liang ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Cesarean Delivery ◽  
Body Mass ◽  
Gestational Age ◽  
Pregnancy Outcomes ◽  
Maternal Age ◽  
Southwest China ◽  
Adverse Pregnancy Outcomes ◽  
Relative Importance ◽  
Adverse Pregnancy

AbstractThe relevance of pregestational body mass index (BMI) on adverse pregnancy outcomes remained unclear in Southwest China. This study aimed to investigate the overall and age-category specific association between pre-gestational BMI and gestational diabetes mellitus (GDM), preeclampsia, cesarean delivery, preterm delivery, stillbirth, macrosomia, and small-for-gestational age (SGA) or large-for-gestational age (LGA) neonates in Southwest China. Furthermore, it explores the relative importance of influence of pregravid BMI and maternal age on pregnancy outcomes. 51,125 Chinese singleton pregnant women were recruited as study subjects. Multiple logistic regression models were used to examine the influence of pre-pregnancy BMI on adverse pregnancy outcomes. Gradient boosting machine was used to evaluate the relative importance of influence of pregravid BMI and maternal age on pregnancy outcomes. It is found that women who were overweight or obese before pregnancy are at higher risk of adverse pregnancy outcomes except for SGA neonates, while pre-pregnancy underweight is a protective factor for GDM, preeclampsia, cesarean delivery, macrosomia and LGA, but not SGA. Younger mothers are more susceptible to GDM and macrosomia neonates, while older mothers are more prone to preeclampsia. Pre-pregnancy BMI has more influence on various pregnancy outcomes than maternal age. To improve pregnancy outcomes, normal BMI weight as well as relatively young maternal ages are recommended for women in child-bearing age.

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