Hazard Assessment of Debris Flow Based on the TFSE: A Case along Jinsha River close to the Jinsha Dam Site in China

2013 ◽  
Vol 405-408 ◽  
pp. 2358-2363
Author(s):  
Bo Shan ◽  
Qing Wang ◽  
Jian Ping Chen ◽  
Hui Xiong

Debris flows are common natural hazards in China. The outbreak of debris flows in reservoir region not only affects the stability of the hydropower stations dam, but also threatens the safety of human life and their property. Therefore, hazard assessment and protection of debris flows close to the dam are necessary and important. In this paper, SPOT5 remote sensing images and DEM model and scene investigation are introduced to acquire the characteristics of debris flow gullies. Ten debris flow occurrence related factors were selected. Then, on the basic of analyzing the relationship of the major factors and fuzzification of debris flow hazard degree, the model of two-stage fuzzy synthetic evaluation (TFSE) was established for hazard assessment. The debris flow risk under different designed rainstorm frequency was calculated. By the evaluation results, we can know that with the design storm intensity increases, the risk of debris flow increases, which is consistent with the actual situation.

2021 ◽  
Author(s):  
Viktoriia Kurovskaia ◽  
Sergey Chernomorets ◽  
Tatyana Vinogradova ◽  
Inna Krylenko

<p>Debris flow is one of the most hazardous events that occur in all mountain regions.  Direct debris flow damage includes loss of human life, destruction of houses and facilities, damage to roads, rail lines and pipelines, vehicle accidents, and many other losses that are difficult to quantify. In July 2015, in the valley of the Barsemdara River (Gorno-Badakhshan Autonomous Region, Tajikistan), plenty of debris flows were observed. As a result, residential areas, social facilities, and infrastructure in Barsem village and neighboring settlements were destroyed and flooded. Besides, debris flow deposits blocked the Gunt River with the subsequent formation of a dammed lake with a maximum volume of 4.0 million m<sup>3</sup>. <br>The aim of this study was to obtain hydrographs of debris flow waves in the source and detailed zoning of the Barsemdara river valley. For the debris flow source, we applied transport-shift model. Equations of this model were developed by Yu.B. Vinogradov basing on Chemolgan experiments of artificial debris flows descending. Previously, the model characteristics were compared with the observational data of the Chemolgan experiments, and the results were found to be satisfactory [Vinogradova, Vinogradov, 2017]. Based on the equations, a computer program was created in the programming language Python. Besides, we improved the model by adding flow velocity calculations, and eventually it became possible to obtain hydrographs. To investigate quantitative characteristics of the debris flow in the river valley we implied a two-dimensional (2D) model called FLO-2D PRO. It is based on the numerical methods for solving the system of Saint-Venant equations. Besides, in this model, it is assumed that debris flows move like a Bingham fluid (viscoplastic fluid) [O'Brien et al., 1993]. The input information for modeling was digital elevation model (DEM) and previously obtained hydrographs. The output information included flow depth, velocity distribution and hazard level of the territory. The results of the study will be reported.</p><p>1.    Vinogradova T.A., Vinogradov A.Y. The Experimental Debris Flows in the Chemolgan River Basin // Natural Hazards. – 2017. – V. 88. – P. 189-198.<br>2.    O'Brien J. S., Julien P.Y., Fullerton W.T. Two-dimensional water flood and mudflow simulation //Journal of hydraulic engineering. – 1993. – V. 119, No 2. – P. 244-261.</p>


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 464 ◽  
Author(s):  
Mei Liu ◽  
Ningsheng Chen ◽  
Yong Zhang ◽  
Mingfeng Deng

Glacial lake outburst floods (GLOF) evolve into debris flows by erosion and sediment entrainment while propagating down a valley, which highly increases peak discharge and volume and causes destructive damage downstream. This study focuses on GLOF hazard assessment in the Bhote Koshi Basin (BKB), where was highly developed glacial lakes and was intensely affected by the Gorkha earthquake. A new 2016 glacial lake inventory was established, and six unreported GLOF events were identified with geomorphic outburst evidence from GaoFen-1 satellite images and Google Earth. A new method was proposed to assess GLOF hazard, in which large numbers of landslides triggered by earthquake were considered to enter into outburst floods enlarge the discharge and volume of debris flow in the downstream. Four GLOF hazard classes were derived according to glacial lake outburst potential and a flow magnitude assessment matrix, in which 11 glacial lakes were identified to have very high hazard and 24 to have high hazard. The GLOF hazard in BKB increased after the earthquake due to landslide deposits, which increased by 216.03 × 106 m3, and provides abundant deposits for outburst floods to evolve into debris flows. We suggest that in regional GLOF hazard assessment, small glacial lakes should not be overlooked for landslide deposit entrainment along a flood route that would increase the peak discharge, especially in earthquake-affected areas where large numbers of landslides were triggered.


2020 ◽  
Author(s):  
Xiaojun Guo

<p><strong>Abstract: </strong>Debris flow monitoring provides valuable data for scitienfic research and early warning, however, it is of difficulty to sucessfully achive because of the great damage of debris flows and the high cost. This report introduces monitoring systems in two debris flow watersheds in western China, the Jiangjia gully (JJG) in Yunnan Province and the Ergou valley in Sichuan Province. JJG is loacted in the dry-hot valley of Jinsha River, and the derbis flows are frequent due to the semi-arid climate, deep-cut topography and highly weathered slope surface. A long-term mornitoring work has been conducted in JJG and more than 500 debris flows events has been recorded since 1965. The monitoring system consists of 10 rainfall gauges and a measuring section, with instruments to measure the flow depth and velocity; and flow density is measured through sampling the fresh debris flow body. Ergou lies in the Wenchuan earthquake affected area and the monitoring began in 2013 to investigate the characteristics and development tendency of post-earthquake debris flows. Three stations were set up in the mainstream and tributaries, with instruments to measure the flow depth, velocity, and density. Over 10 debris flow events were recorded up to date.</p><p>Based on the monitoring output, the rainfall spatial distribution and thresholds for debris flows are proposed. The debris flow dynamics characteristics are analyzed, and the relations between the parameters, e.g. density, velocity, discharge and grain compositions are presented. The debris flow formation modes and the mechanisms in different regions are discriminated and simulation methods are suggested. It is anticipated that the monitoring results will promote understanding of debris flow characteristics in the western China.</p><p><strong>Keywords:</strong> Debris flow, monitoring, rainfall, discharge, formation. </p>


Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1206 ◽  
Author(s):  
Monia Calista ◽  
Valeria Menna ◽  
Vania Mancinelli ◽  
Nicola Sciarra ◽  
Enrico Miccadei

The purpose of this research is to estimate the rockfall and debris flow hazard assessment of the SW escarpment of the Montagna del Morrone (Abruzzo, Central Italy). The study investigated the geomorphology of the escarpment, focusing on the type and distribution of the present landforms. Particular attention was devoted to the slope gravity landforms widely developed in this area, where the effective activity of the gravitational processes is mainly related to the rockfall and debris flows and documented by numerous landslides over time. Working from orography, hydrography, lithology, and geomorphology, the landslide distribution and their potential invasion areas were evaluated through two specific numerical modeling software. RAMMS and Rockyfor3D calculation codes were used in order to analyze the debris flow and rockfall type of landslides, respectively. The obtained results are of great interest when evaluating the hazard assessment in relation to the potential landslides. Moreover, the geographic information systems (GIS) provide a new geomorphological zonation mapping, with the identification of the detachment and certain and/or possible invasion areas of the landslide blocks. This method provides an effective tool to support the correct territorial planning and the management of the infrastructural settlements present in the area and human safety.


2010 ◽  
Vol 58 (1) ◽  
pp. 459-477 ◽  
Author(s):  
Wen Zhang ◽  
Hui-Zhong Li ◽  
Jian-ping Chen ◽  
Chen Zhang ◽  
Li-ming Xu ◽  
...  

2020 ◽  
Vol 20 (5) ◽  
pp. 1287-1304 ◽  
Author(s):  
Zhu Liang ◽  
Changming Wang ◽  
Songling Han ◽  
Kaleem Ullah Jan Khan ◽  
Yiao Liu

Abstract. The existence of debris flows not only destroys the facilities but also seriously threatens human lives, especially in scenic areas. Therefore, the classification and susceptibility analysis of debris flow are particularly important. In this paper, 21 debris flow catchments located in Huangsongyu Township, Pinggu District, Beijing, China, were investigated. Besides field investigation, a geographic information system, a global positioning system and remote-sensing technology were applied to determine the characteristics of debris flows. This article introduced a clustering validity index to determine the clustering number, and the fuzzy C-means algorithm and factor analysis method were combined to classify 21 debris flow catchments in the study area. The results were divided into four types: debris flow closely related to scale–topography–human activity, topography–human activity–matter source, scale–matter source–geology and topography–scale–matter source–human activity. Nine major factors screened from the classification result were selected for susceptibility analysis, using both the efficacy coefficient method and the combination weighting. Susceptibility results showed that the susceptibility levels of 2 debris flow catchments were high, 6 were moderate and 13 were low. The assessment results were consistent with the field investigation. Finally, a comprehensive assessment including classification and susceptibility evaluation of debris flow was obtained, which was useful for risk mitigation and land use planning in the study area and provided a reference for the research on related issues in other areas.


2016 ◽  
Author(s):  
C. K. Chung ◽  
H. S. Kim ◽  
S. R. Kim ◽  
K. S. Kim

Abstract. Debris flows caused by heavy rainfall in mountain areas near expressways lead to severe social and economic loss and sometimes even result in casualties. However, in Korea, the design of road structures that resist these debris flow incidents are generally not carried out in a systematic way with proper concepts or procedures. Therefore, the development of a real-time system for debris flow hazard assessment is necessary to provide preliminary information for rapid decision making of evacuations or restoration measures, and to prevent second-hand disasters caused by debris flows. Recently, various map-based approaches have been proposed using multi-attribute criteria and assessment methods for debris flow susceptibilities. However, for the macro-zonation of debris flow hazards at a national scale, a simplified method such as the Korea Expressway Corporation debris flow hazard assessment method is appropriate and also applicable for systemization based on GIS and monitoring networks. In this study, a GIS-based real-time framework of debris flow hazards for expressway sections was newly proposed based on the KEC debris flow hazard assessment method. First, the KEC-based method was standardized in a systematic fashion using ESRI ArcGIS, enabling the objective and quantitative acquisition of various attribute datasets. Also, for a more precise assessment, the quantification of rainfall criteria was considered. Finally, a safety management system for debris flow hazards was developed based on a GIS platform, and was applied and verified on three expressway sections in Korea.


Sign in / Sign up

Export Citation Format

Share Document