Outlining a stepwise, multi-parameter debris flow monitoring and warning system: an example of application in Aizi Valley, China

Author(s):  
Ningsheng Chen

<p>Abstract: In recent years, the increasing frequency of debris flow demands enhanced effectiveness and efficiency are essential not only from an economic point of view but are also considered as a frontline approach to alleviate hazards. Currently, the key issues are the imbalance between the limited lifespan of equipment, the relatively long period between the recurrences of such hazards, and the wide range of critical rainfall that trigger these disasters. This paper attempt to provide a stepwise multi-parameter debris flow warning system after taking into account the shortcomings observed in other warning systems. The whole system is divided into five stages. Different warning levels can be issued based on the critical rainfall thresholds. Monitoring starts when early warning is issued and it continues with debris flow near warning, movement warning and hazard warning stages. For early warning, historical archives of earthquake and drought are used to choose a debris flow susceptible site for further monitoring, Secondly, weather forecasts provide an alert of possible near warning. Hazardous precipitation, model calculation and debris flow initiation tests, pore pressure sensors and water content sensors are combined to check the critical rainfall and to publically announce a triggering warning. In the final two stages, equipment such as rainfall gauges, flow stage sensors, vibration sensors, low sound sensors and infrasound meters are used to assess movement processes and issue hazard warnings. In addition to these warnings, community-based knowledge and information is also obtained and discussed in detail. The proposed stepwise, multi-parameter debris flow monitoring and warning system has been applied in Aizi valley China which continuously monitors the debris flow activities.</p>

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.


2016 ◽  
Vol 16 (2) ◽  
pp. 483-496 ◽  
Author(s):  
D. L. Liu ◽  
S. J. Zhang ◽  
H. J. Yang ◽  
L. Q. Zhao ◽  
Y. H. Jiang ◽  
...  

Abstract. The activities of debris flow (DF) in the Wenchuan earthquake-affected area significantly increased after the earthquake on 12 May 2008. The safety of the lives and property of local people is threatened by DFs. A physics-based early warning system (EWS) for DF forecasting was developed and applied in this earthquake area. This paper introduces an application of the system in the Wenchuan earthquake-affected area and analyzes the prediction results via a comparison to the DF events triggered by the strong rainfall events reported by the local government. The prediction accuracy and efficiency was first compared with a contribution-factor-based system currently used by the weather bureau of Sichuan province. The storm on 17 August 2012 was used as a case study for this comparison. The comparison shows that the false negative rate and false positive rate of the new system is, respectively, 19 and 21 % lower than the system based on the contribution factors. Consequently, the prediction accuracy is obviously higher than the system based on the contribution factors with a higher operational efficiency. On the invitation of the weather bureau of Sichuan province, the authors upgraded their prediction system of DF by using this new system before the monsoon of Wenchuan earthquake-affected area in 2013. Two prediction cases on 9 July 2013 and 10 July 2014 were chosen to further demonstrate that the new EWS has high stability, efficiency, and prediction accuracy.


2019 ◽  
Vol 17 (9) ◽  
pp. 818-822 ◽  
Author(s):  
Flaminia Pantano ◽  
Silvia Graziano ◽  
Roberta Pacifici ◽  
Francesco Paolo Busardò ◽  
Simona Pichini

In the last few years, a wide range of new psychoactive substances (NPS) have been produced and marketed to elude the controlled substance lists. These molecules enter the traditional illegal and web market with poor knowledge about their toxicity, mechanism of action, metabolism, abuse potential so that they are directly tested by the consumers. This perspective highlights the main issues connected with NPS: the celerity they enter and leave the market once included in the banning laws to be substituted by new legal analogues; the unavailability of analytical screening tests and certified standards to perform toxicological analyses; the time lag between NPS identification and inclusion in the controlled substances lists. Finally, the authors take a snapshot of the commitment of the Italian Early Warning System in highlighting the recent seizures of NPS as well as the distribution of NPS related intoxication and deaths as an example of what is happening in the European countries and internationally.


2019 ◽  
Vol 19 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Jian Huang ◽  
Theodoor Wouterus Johannes van Asch ◽  
Changming Wang ◽  
Qiao Li

Abstract. Gully-type debris flow induced by high-intensity and short-duration rainfall frequently causes great loss of properties and causalities in mountainous regions of southwest China. In order to reduce the risk by geohazards, early warning systems have been provided. A triggering index can be detected in an early stage by the monitoring of rainfall and the changes in physical properties of the deposited materials along debris flow channels. Based on the method of critical pore pressure for slope stability analysis, this study presents critical pore pressure threshold in combination with rainfall factors for gully-type debris flow early warning. The Wenjia gully, which contains an enormous amount of loose material, was selected as a case study to reveal the relationship between the rainfall and pore pressure by field monitoring data. A three-level early warning system (zero, attention, and warning) is adopted and the corresponding judgement conditions are defined in real time. Based on this threshold, there are several rainfall events in recent years have been validated in Wenjia gully, which prove that such a combined threshold may be a reliable approach for the early warning of gully-type debris flow to safeguard the population in the mountainous areas.


2012 ◽  
Vol 326-328 ◽  
pp. 330-334 ◽  
Author(s):  
Jan Valíček ◽  
Jana Müllerová ◽  
Vlastimil Kuběna ◽  
Pavel Koštial ◽  
Marta Harničárová ◽  
...  

Pollutants can be classified according to their chemical composition, harmfulness, hazardousness, risk rate and toxicity. The most monitored pollutants are particulate matter (PM), carbon monoxide (CO), nitrogen oxide (NOx), sulfur dioxide (SO2), organic substances which are in the form of gaseous phase in waste gases expressed as total organic carbon, dibenzodioxins and dibenzofurans [1-3]. Other pollutants are divided into several groups and subgroups, such as substances with carcinogenic effects (asbestos, Co, Cd, Be, Ni, As, Cr, dioxins, etc.), solid inorganic contaminants (He, Se, animony, and others) and inorganic pollutants in the form of gases (HCl, HF, ammonia, etc.), organic gases and vapours (phenol, toluene, acetone and many others) and gases causing the greenhouse effect (CO2, methane, N2O, hydrofluorocarbons, etc.). The term particulate matter, or suspended matter refers to the emissions of a wide range of wind drift solids and liquid particles of material in size from several nanometres up to 0.5 mm, which stay in the air for some time. This is a major component of atmospheric pollution, which contributes to harmful effects not only on human health but also on intensity of materials degradation. Into the atmosphere, where we can meet them, regardless of particle size and chemical composition, in the form of a complex heterogeneous mixture, they are released from burning fossil fuels and also from burning biomass-based fuels, while domestic heating accounts for about 16% of the total production of particulate matter [4,5,6]. This percentage represents a degree of imperfect combustion of fuels used in local heating. Emissions from incomplete combustion are undesirable from the point of view of human health as well as from the economic point of view, because this leads to the degradation of materials. Nevertheless, since fuel combustion is necessary for the society, emissions are still produced. This paper presents an automated method of perfect combustion control in local heating in order to minimize emissions being produced.


2021 ◽  
Vol 2129 (1) ◽  
pp. 012035
Author(s):  
Nurshahirah Shaharudin ◽  
Mohd Zamri Hasan ◽  
Syatirah Mohd Noor

Abstract The direct current motor is an important drive configuration for many applications across a wide range of power and speeds. It has variable characteristics and is used extensively in variable-speed drives. The goals of this project are to control the direction and speed of a Direct Current (DC) motor. Due to the advancement of wireless technology, there are several communication devices introduced such as GSM, Wi-Fi, ZIGBEE and Bluetooth. Each of the connections has its own unique specification and application. Among these wireless connections, Bluetooth technology is often implemented and can be sent from the mobile phone at a distance of 10 meters. The speed control was implemented using Bluetooth technology to provide communication access from a smartphone. Instead, the ARDUINO UNO platform can be used to quickly promote electronic systems. And an electronics technique is called Pulse Width Modulation (PWM) is used to achieve speed control, and this technique generates high and low pulses, then these pulses vary the speed in the motor. In order to control this PWM pulse, variable resistors are used and depend on it the speed of the DC motor will increase or decrease. The variable resistor is adjusting to varying the speed of the motor, and the higher the resistance the lower the speed of the motor rotates. The direction of the motor is controlled by the relay by giving and giving a command on the virtual terminal. The speed of the motor is directly proportional to the resistance as the speed increased after the resistance also increased and vice versa. The significance of this study is practical and highly feasible from the economic point of view and has the advantage of running the motor at a higher rating in term of a reliable, durable, accurate and efficient way of controlling speed and direction control.


2002 ◽  
Vol 46 (3) ◽  
pp. 41-49 ◽  
Author(s):  
W.M. Grayman ◽  
R.M. Males

An early warning system is a mechanism for detecting, characterizing and providing notification of a source water contamination event (spill event) in order to mitigate the impact of contamination. Spill events are highly probabilistic occurrences with major spills, which can have very significant impacts on raw water sources of drinking water, being relatively rare. A systematic method for designing and operating early warning systems that considers the highly variable, probabilistic nature of many aspects of the system is described. The methodology accounts for the probability of spills, behavior of monitoring equipment, variable hydrology, and the probability of obtaining information about spills independent of a monitoring system. Spill Risk, a risk-based model using Monte Carlo simulation techniques has been developed and its utility has been demonstrated as part of an AWWA Research Foundation sponsored project. The model has been applied to several hypothetical river situations and to an actual section of the Ohio River. Additionally, the model has been systematically applied to a wide range of conditions in order to develop general guidance on design of early warning systems.


2020 ◽  
Vol 101 (4) ◽  
pp. E368-E393 ◽  
Author(s):  
Samuel Jonson Sutanto ◽  
Henny A. J. Van Lanen ◽  
Fredrik Wetterhall ◽  
Xavier Llort

Abstract Drought early warning systems (DEWS) have been developed in several countries in response to high socioeconomic losses caused by droughts. In Europe, the European Drought Observatory (EDO) monitors the ongoing drought and forecasts soil moisture anomalies up to 7 days ahead and meteorological drought up to 3 months ahead. However, end users managing water resources often require hydrological drought warning several months in advance. To answer this challenge, a seasonal pan-European DEWS has been developed and has been running in a preoperational mode since mid-2018 under the EU-funded Enhancing Emergency Management and Response to Extreme Weather and Climate Events (ANYWHERE) project. The ANYWHERE DEWS (AD-EWS) is different than other operational DEWS in the sense that the AD-EWS provides a wide range of seasonal hydrometeorological drought forecasting products in addition to meteorological drought, that is, a broad suite of drought indices that covers all water cycle components (drought in precipitation, soil moisture, runoff, discharge, and groundwater). The ability of the AD-EWS to provide seasonal drought predictions in high spatial resolution (5 km × 5 km) and its diverse products mark the AD-EWS as a preoperational drought forecasting system that can serve a broad range of different users’ needs in Europe. This paper introduces the AD-EWS and shows some examples of different drought forecasting products, the drought forecast score, and some examples of a user-driven assessment of forecast trust levels.


Author(s):  
Amélie Grangeat ◽  
Stéphane Raclot ◽  
Floriane Brill ◽  
Emmanuel Lapebie

Vehicles or freight cars on fire below a bridge or inside a tunnel are exceptional events and imply difficult intervention conditions for firefighters. A buried technical network like high voltage electricity line, gas or steam pipeline around such a fire causes additional specifics risks. Vulnerability areas for firefighters are zones where both factors exist: a difficult incident area together with a specific risk like buried networks. They require intervention teams with specific emergency response capabilities. The paper proposes a method developed for the Paris Fire Brigade for vulnerability mapping. Results aim at improving the mobilization in allocating directly the specific responses capabilities intervention teams. Results are debated from an operational point of view. Cutting off several network lines during firefighters' interventions may strongly affect the society. In case of simultaneous incidents in vulnerable areas, firefighters could be an early warning system and inform authorities of the risk of services disruption.


Author(s):  
Amélie Grangeat ◽  
Stéphane Raclot ◽  
Floriane Brill ◽  
Emmanuel Lapebie

Vehicles or freight cars on fire below a bridge or inside a tunnel are exceptional events and imply difficult intervention conditions for firefighters. A buried technical network like high voltage electricity line, gas or steam pipeline around such a fire causes additional specifics risks. Vulnerability areas for firefighters are zones where both factors exist: a difficult incident area together with a specific risk like buried networks. They require intervention teams with specific emergency response capabilities. The paper proposes a method developed for the Paris Fire Brigade for vulnerability mapping. Results aim at improving the mobilization in allocating directly the specific responses capabilities intervention teams. Results are debated from an operational point of view. Cutting off several network lines during firefighters' interventions may strongly affect the society. In case of simultaneous incidents in vulnerable areas, firefighters could be an early warning system and inform authorities of the risk of services disruption.


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