The Influence of Debris Flow on Lake Depositon: An Case from Guanba River in Qionghai Lake Basin

2014 ◽  
Vol 1010-1012 ◽  
pp. 1129-1139
Author(s):  
Jian Guo Yue ◽  
Yun Long Qi ◽  
Xue Li Wei ◽  
Ning Sheng Chen

Sediment deposition caused by debris flows is an important process controlling the evolution and regression of lake, and even a pervasive environmental problem. The frequent debris flows construct a vital links between mountain slope and Qiong Lake transporting lots of sediment into lake, and further making the lake depth and lake area shallower and smaller constantly. In the paper, we select the Guanba River in the northeast of Qiong Lake as a case studying the effect of debris flows on Lake depositon and the characteristics of typical debris flow, and document the sediment deposition in the Guanba River estuary. The control factors contributing to debris flow initiation indicate that the debris flows are drove by rainfall, earthquake and human activities together, and the occurrence frequency of debris flows in the study area will continue to increase.

2012 ◽  
Vol 599 ◽  
pp. 709-715 ◽  
Author(s):  
Xue Li Wei ◽  
Yun Long Qi ◽  
Qian Gong Cheng ◽  
Ning Sheng Chen

Sediment deposition caused by debris flows and floods is an important process controlling the evolution and regression of lake, and even a pervasive environmental problem. Qiong Lake is regards as a “bright phearl of the altiplano” in the Yunnan Plateau, and because debris flows construct a vital links between mountain slope and Qiong Lake, so the debris flows drove by rainfall will control the evolution rule of rift lakes. Based on the data of lake shorelines of Qiong Lake, it was found that the shoreline was push forward by 665 m since 1998. In addition, in the recent 30 years, turbidity current deposits have generated underwater levee and other landscapes in the deep water area of Qiong River. This paper has analyzed the matter migration process induced by debris flows, and presented the regime change pattern of debris flow along river channel and corresponding mechanical mechanism, mainly revealed the submarine transportation and deposition pattern of debris flow. The above studies provide a helpful way of comprehending the formation mechanism of turbidity flow induced by debris flow, and the transportation pattern. Based on severe sediment deposition catastrophes in this kind of rift lakes from debris flows and floods, disaster mitigation must be planned and appropriate engineering countermeasures put in place as soon as possible.


2021 ◽  
Vol 10 (7) ◽  
pp. 466
Author(s):  
Wenbo Mo ◽  
Yunlin Zhao ◽  
Nan Yang ◽  
Zhenggang Xu ◽  
Weiping Zhao ◽  
...  

Spatial and quantitative assessments of water yield services in watershed ecosystems are necessary for water resource management and improved water ecological protection. In this study, we used the InVEST model to estimate regional water yield in the Dongjiang Lake Basin in China. Moreover, we designed six scenarios to explore the impacts of climate and land use/land cover (LULC) changes on regional water yield and quantitatively determined the dominant mechanisms of water yield services. The results are expected to provide an important theoretical reference for future spatial planning and improvements of ecological service functions at the water source site. We found that (1) under the time series analysis, the water yield changes of the Dongjiang Lake Basin showed an initial decrease followed by an increase. Spatially, water yield also decreased from the lake area to the surrounding region. (2) Climate change exerted a more significant impact on water yield changes, contributing more than 98.26% to the water yield variability in the basin. In contrast, LULC had a much smaller influence, contributing only 1.74 %. (3) The spatial distribution pattern of water yield services in the watershed was more vulnerable to LULC changes. In particular, the expansion of built-up land is expected to increase the depth of regional water yield and alter its distribution, but it also increases the risk of waterlogging. Therefore, future development in the basin must consider the protection of ecological spaces and maintain the stability of the regional water yield function.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 750
Author(s):  
Antonio Pasculli ◽  
Jacopo Cinosi ◽  
Laura Turconi ◽  
Nicola Sciarra

The current climate change could lead to an intensification of extreme weather events, such as sudden floods and fast flowing debris flows. Accordingly, the availability of an early-warning device system, based on hydrological data and on both accurate and very fast running mathematical-numerical models, would be not only desirable, but also necessary in areas of particular hazard. To this purpose, the 2D Riemann–Godunov shallow-water approach, solved in parallel on a Graphical-Processing-Unit (GPU) (able to drastically reduce calculation time) and implemented with the RiverFlow2D code (version 2017), was selected as a possible tool to be applied within the Alpine contexts. Moreover, it was also necessary to identify a prototype of an actual rainfall monitoring network and an actual debris-flow event, beside the acquisition of an accurate numerical description of the topography. The Marderello’s basin (Alps, Turin, Italy), described by a 5 × 5 m Digital Terrain Model (DTM), equipped with five rain-gauges and one hydrometer and the muddy debris flow event that was monitored on 22 July 2016, were identified as a typical test case, well representative of mountain contexts and the phenomena under study. Several parametric analyses, also including selected infiltration modelling, were carried out in order to individuate the best numerical values fitting the measured data. Different rheological options, such as Coulomb-Turbulent-Yield and others, were tested. Moreover, some useful general suggestions, regarding the improvement of the adopted mathematical modelling, were acquired. The rapidity of the computational time due to the application of the GPU and the comparison between experimental data and numerical results, regarding both the arrival time and the height of the debris wave, clearly show that the selected approaches and methodology can be considered suitable and accurate tools to be included in an early-warning system, based at least on simple acoustic and/or light alarms that can allow rapid evacuation, for fast flowing debris flows.


Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2314 ◽  
Author(s):  
Shu Wang ◽  
Anping Shu ◽  
Matteo Rubinato ◽  
Mengyao Wang ◽  
Jiping Qin

Non-homogeneous viscous debris flows are characterized by high density, impact force and destructiveness, and the complexity of the materials they are made of. This has always made these flows challenging to simulate numerically, and to reproduce experimentally debris flow processes. In this study, the formation-movement process of non-homogeneous debris flow under three different soil configurations was simulated numerically by modifying the formulation of collision, friction, and yield stresses for the existing Smoothed Particle Hydrodynamics (SPH) method. The results obtained by applying this modification to the SPH model clearly demonstrated that the configuration where fine and coarse particles are fully mixed, with no specific layering, produces more fluctuations and instability of the debris flow. The kinetic and potential energies of the fluctuating particles calculated for each scenario have been shown to be affected by the water content by focusing on small local areas. Therefore, this study provides a better understanding and new insights regarding intermittent debris flows, and explains the impact of the water content on their formation and movement processes.


2013 ◽  
Vol 347-350 ◽  
pp. 975-979
Author(s):  
Rong Zhao ◽  
Cai Hong Li ◽  
Yun Jian Tan ◽  
Jun Shi ◽  
Fu Qiang Mu ◽  
...  

This paper presents a Debris Flow Disaster Faster-than-early Forecast System (DFS) with wireless sensor networks. Debris flows carrying saturated solid materials in water flowing downslope often cause severe damage to the lives and properties in their path. Faster-than-early or faster-than-real-time forecasts are imperative to save lives and reduce damage. This paper presents a novel multi-sensor networks for monitoring debris flows. The main idea is to let these sensors drift with the debris flow, to collect flow information as they move along, and to transmit the collected data to base stations in real time. The Raw data are sent to the cloud processing center from the base station. And the processed data and the video of the debris flow are display on the remote PC. The design of the system address many challenging issues, including cost, deployment efforts, and fast reaction.


2021 ◽  
Author(s):  
Georg Stauch ◽  
Alexander Esch ◽  
Lukas Dörwald ◽  
Verena Esser ◽  
Simone Lechthaler ◽  
...  

<p>The sediments of the artificial Urft reservoir represent a unique archive of human influence on late Holocene sediment composition. The Urft dam, located in the Eifel Mountains in western Germany, was built between 1900 and 1905. At the time of its construction, the Urft reservoir was the largest reservoir and, with 12 MW, drove the most powerful water storage power plant in Europe. The reservoir has a length of 12 km and, when fully dammed, has a volume of 45.51 million m³ over an area of 2.16 km². The most important inflow is the river Urft. Today, the Urft Lake is completely enclosed by the Eifel National Park.</p><p>Consequently, sediments were deposited in the lake almost undisturbed over the last 115 years. Due to construction work on the Urft dam and the inspection of the 2.7 km long Kermeter Tunnel, which powers the Heimbach hydroelectric power plant, the reservoir was almost completely drained in November 2020. This offered the rare opportunity to sample the deposits in detail and to record the entire lake area photogrammetrically using an Unmanned Aircraft System (UAS). The work was carried out in cooperation between the Water Board Eifel-Rur (WVER) and the Chair of Physical Geography and Geoecology (PGG) at RWTH Aachen University.</p><p>Within the framework of the project, the sediments in the reservoir will be investigated in detail. The comparison of the high-resolution UAS digital elevation models and historical maps will give insights in the amount of sediment deposition in the different areas of the lake during the last 115 years. Geochemical markers will be used to quantify the anthropogenic influence on the sediments in the form of mining-induced pollutant contamination (e.g., heavy metals) and to relate this to the history of use in the catchment area. Another focus will be on recording the microplastics content of the different sediment layers. Since microplastics have only been introduced into the natural system by humans for the last 70 years since the beginning of mass production around 1950, the sediment layers can also be differentiated in terms of time. For these investigations, a total of ten sediment cores with a length of up to 4 m were taken from the deposits.</p>


2021 ◽  
Vol 27 (1) ◽  
pp. 3-27
Author(s):  
Jeremy T. Lancaster ◽  
Brian J. Swanson ◽  
Stefani G. Lukashov ◽  
Nina S. Oakley ◽  
Jacob B. Lee ◽  
...  

ABSTRACT The post–Thomas Fire debris flows of 9 January 2018 killed 23 people, damaged 558 structures, and caused severe damage to infrastructure in Montecito and Carpinteria, CA. U.S. Highway 101 was closed for 13 days, significantly impacting transportation and commerce in the region. A narrow cold frontal rain band generated extreme rainfall rates within the western burn area, triggering runoff-driven debris flows that inundated 5.6 km2 of coastal land in eastern Santa Barbara County. Collectively, this series of debris flows is comparable in magnitude to the largest documented post-fire debris flows in the state and cost over a billion dollars in debris removal and damages to homes and infrastructure. This study summarizes observations and analyses on the extent and magnitude of inundation areas, debris-flow velocity and volume, and sources of debris-flow material on the south flank of the Santa Ynez Mountains. Additionally, we describe the atmospheric conditions that generated intense rainfall and use precipitation data to compare debris-flow source areas with spatially associated peak 15 minute rainfall amounts. We then couple the physical characterization of the event with a compilation of debris-flow damages to summarize economic impacts.


2021 ◽  
Author(s):  
Juan Daniel Rios-Arboleda

<p>This research expands the original analysis of Baker and Costa (1987) including data from Europe and South America with the objective to understand if there are emerging latitudinal patterns. In addition, the threshold proposed by Zimmermann et al. (1997) it is evaluated with the data from tropical zones finding that this is a good predictor.</p><p>Mainly, recent Debris Flow occurred in South America are analyzed with the aim of identifying the best risk management strategies and their replicability for developing countries, particularly, the cases that have occurred in Colombia and Venezuela in the last 30 years are analyzed in order to compare management strategies and understand which are the most vulnerable areas to this phenomenon.</p><p>It is concluded that large-scale and multinational projects such as SED ALP are required in South America to better characterize events that have left multiple fatalities (sometimes hundreds of people) and better understand how to manage the risk on densely populated areas.</p><p>Finally, the use of amateur videos is proposed to characterize these events in nations with limited budgets for projects such as SED ALP, methodology that will be described extensively in later works.</p>


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