Socio-scientific quantification of the comprehensive benefits of debris flow mitigation measures for villages in western Sichuan, China

Debris flow hazards seriously threaten thesafety and sustainable development of mountainousareas. Numerous debris flow mitigation measures havebeen implemented worldwide;however, acomprehensive assessment of the specific disasterreduction effects of these measures and their economic,social and ecological benefits is yet to be performed.The western region of Sichuan Province frequentlysuffers from geohazards such as debris flow, and thegovernment has adopted many mitigation measures.This study assessed the benefits of debris flowmitigation measures and identified the key influencingfactors via a field-based study conducted in 81 villagesin western Sichuan province, China. A framework forthe evaluation of the benefits of rural debris flowmitigation measures was constructed andquantitatively evaluated using a survey. Snowballsampling was performed to recruit 81 village leadersand 468 farmers. The results showed that managementand engineering measures were the main methodsused to mitigate debris flow;ecological measures wereauxiliary. The average satisfaction scores of farmers forthese three types of measures were 4.07, 3.90, and 3.56,respectively (as measured on a five-point Likert scale).In contrast, in terms of the benefits of these mitigationmeasures, only a small proportion of villages (11.11%)obtained a high level of comprehensive benefits fromthe debris flow mitigation measures, while the majority(88.89%) received medium to low-level benefits. Toimprove this situation, we further studied and foundthat the main factors that restricted villages fromachieving high-level comprehensive benefits were theunpredictable nature of debris flows, labour forceoutflow and remoteness. Effective control measures, agood economic environment and strong governmentassistance were reported as crucial factors forimproving these comprehensive benefits. This studyprovides socio-scientific references for decisionmakingon rural debris flow mitigation measures while keeping villages at the centre of economic development.

On the Polygonal Wear Evolution of Heavy-Haul Locomotive Wheels due to Wheel/Rail Flexibility and Its Mitigation Measures

Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external excitations.In this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is implemented.Further,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are discussed.The results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and rails.Execution of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal wear.This research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.

Mitigation measures of debris flow and landslide risk carried out in two mountain areas of North-Eastern Italy

The design of remediation works for the mitigation and prevention of the associated risk is needed where these geological hazards affect anthropized areas. Remedial measures for landslides commonly include slope reshaping, plumbing, drainage, retaining structures and internal slope reinforcement, while debris flow control works consist in open or closed control structures. The effectiveness of the remedial works implemented must be assessed by evaluating the reduction of the risk over time. The choice of the most appropriate and cost-effective intervention must consider the type of hazard and environmental issues, and selects, wherever possible, naturalistic engineering operations that are consequently implemented according to the environmental regulations or the design and specification standards imposed by the competent public administrations. The mitigation procedures consist of five basic steps:(a) acquisition of the knowledge of the hazard process;(b) risk assessment with identification of possible disaster scenarios;(c) planning and designing of specific remedial measures to reduce and/or eliminate the potential risk;(d) slope monitoring after application of remedial measures,(e) transfer of knowledge to the stakeholders. This paper presents two case studies describing the practice for the design of the mitigation measures adopted for debris flow and active landslide sites in North-Eastern Italy. The first case study is a debris flow site, for which, based on observation of past events and numerical simulations using the software FLOW-2D, the most suitable mitigation measures were found to be the construction of a debris basin, barriers and breakers. The second case study deals with an active landslide threatening a village. Based on the landslide kinematics and the results of numerical simulations performed with the code FLAC, hard engineering remedial works were planned to reduce the driving forces with benching and by increasing the available resisting forces using jet grout piles and deep drainage.

Ground-borne vibrations induced by impact pile driving: experimental assessment and mitigation measures

Impact pile driving is an interesting technique for the construction of deep foundations from a practical and economical point of view.However,the generalization of this technique can be restricted due to the excessive vibration levels that can be generated,which can be especially problematic in residential areas.However,different mitigation measures can be applied to prevent excessive vibration levels inside buildings located near construction sites.To compare its efficiency through a numerical prediction tool,two experimental test sites are first presented and characterized.From the results obtained,it was found that the construction of an open trench near the impact source can be used as an efficient mitigation measure to reduce the maximum vibration levels evaluated in this study.

Research Progress on the Mechanism of Crop Saline-alkali Tolerance and Mitigation Measures

The wide distribution of saline-alkali land in China is a restrictive factor for the sustainable development of agriculture.Saline-alkaline soil inhibits the growth and development of crops,reducing its yield and quality.In this article,we summarized the germination status,physiological characteristics,response mechanisms and mitigation measures of different crops under saline-alkali stress in recent years,aiming to provide important reference for the study of saline-alkali tolerance mechanism in crops,cultivation of crop varieties tolerant to salts and alkalis and improvement of the utilization rate of saline-alkali land,and put forward suggestions for future development trend of saline-alkali land crops and mitigation measures.

Using a Coupled Air Quality Modeling System for the Development of an Air Quality Plan in Madrid (Spain): Source Apportionment and Analysis Evaluation of Mitigation Measures

In this contribution, we use a coupled air quality modelling system (AQM) as a tool to design and develop an air quality plan in Madrid. AQM has allowed us to obtain a preliminary evaluation of the effect of mitigation measures over regional and local air quality levels. To achieve these goals, we have prepared a sophisticated AQM, coupling the meteorological model WRF, the emission model AEMM, and the photochemical model CMAQ. AQM was evaluated using the whole modelling year 2010 working with high horizontal resolution, 3 km for the region of Madrid and 1km for urban metropolitan area of Madrid. Two different analyses have been realized: a source apportionment exercise following a zero-out methodology to obtain the contribution to the air quality levels of the different emission sector;and an evaluation of the main mitigation measures considered in the air quality plan using sensitivity analysis. The air quality plan was focused on the improvement of NO2 levels and AQM analyzed the effect of the mitigation measures during ten episodes of 2011 where NO2 or O3 levels were the highest of the year;so we analyzed the effect of the mitigation plan in worst conditions. Results provided by the AQM system show that it accomplishes the European Directive modelling uncertainty requirements and the mean absolute gross error for 1-h maximum daily NO2 is 31% over locations with higher levels of this atmospheric pollutant;the road traffic is the main contributor to the air quality levels providing a 81% for NO2, 67% for CO and 46% for PM10;measures defined in the plan achieve to reduce up to 11 μgm-3 NO2 levels offering highest reductions over urban areas with traffic influence.

Study on the Causes of Rural Lightning Disaster and Countermeasures of Lightning Protection and Disaster Reduction

With the development of the time and the progress of economy,great changes have taken place in the environment.In recent years,it is common to see bad weather,such as hurricane,drought,lightning and so on.The emergence of these weather has the greatest impact on farmers and crops,especially the lightning weather,not only that,but also sometimes cause personal injury.In face of the frequent occurrence of bad weather in recent years and its harm and threat to China's agriculture,rural areas,personnel,etc.,the author makes a detailed study on the causes of rural lightning weather,analyzes the lightning protection measures in rural areas and their shortcomings,and summarizes the relevant improvement measures.

Management of Significant Environmental Aspects and Impacts in Accordance with the ISO 14001:2015 Standard during the Operation and Maintenance Phase of Senegal River Basin Development Authority Hydroelectric Works and Facilities: The Case of Manantali Dam

This study aims to determine the environmental aspects and impacts of the phase relating to the operation of Manantali’s hydroelectric structures and facilities according to the requirements of the ISO 14001 version 2015 standard. To do this, the mapping of the different work areas made it possible to identify all the activities within the framework of the farm. Based on the mapping, environmental measurements made including noise level, brightness, electric and magnetic fields, total particles, PM10, PM2.5, PM1 showed the work areas with the exposure limit values exceeded. The inventories of the waste produced show eighteen (18) types of waste, 67% of which are special industrial waste (SIW), 28% are ordinary industrial waste (OIW) and 5% are inert industrial waste (IIW). The identification and assessment of environmental aspects and impacts made it possible to determine sixteen (16) positive and negative significant environmental aspects (ESAs). The positive AES must be maintained, and for the negative ones, mitigation and mitigation measures must be put in place in order to manage them effectively. This will ultimately improve environmental management in the operation of hydroelectric structures and facilities.

Pioneering Micro-Scale Mapping of Urban CO_(2)Emissions from Fossil Fuels with GIS

Urban areas globally are escalating contributors to carbon dioxide(CO_(2))emissions,challenging sustainable development.This study proposes a novel micro-scale approach utilizing GIS to quantify CO_(2)emission spatial distribution,enhancing urban sustainability assessment.Employing a“bottom-up”methodology,emissions were calculated for various sources,revealing Isfahan’s urban area emits 13,855,525 tons of CO_(2)annually.Major contributors include stationary and mobile sources such as power plants(50.61%),road and rail transport(17.18%),and residential sectors(21.78%).Spatial distribution mapping showed that 81.68%of CO_(2)emissions originate from stationary sources,notably power plants.Furthermore,mobile sources,including road transport,contribute 17.16%,with emissions concentrated in main urban arteries.Agricultural machinery adds 1.14%of emissions,spatially distributed across Isfahan’s agricultural lands.Integration of emissions maps depicts the city’s total CO_(2)emissions,highlighting sectoral contributions.Despite limitations in data granularity,this study provides valuable insights into urban CO_(2)emissions dynamics,facilitating targeted mitigation strategies.Quantitative achievements include precise CO_(2)emission quantification and spatial distribution mapping,crucial for formulating effective urban sustainability policies.

Prioritizing landscapes for mitigating the impacts of onshore wind farms on multidimensional waterbird diversity in the Yellow Sea

Ongoing wind energy developments play a key role in mitigating the global effects of climate change and the energy crisis;however,they have complex ecological consequences for many flying animals.The Yellow Sea coast is considered as an ecological bottleneck for migratory waterbirds along the East Asian–Australasian flyway(EAAF),and is also an important wind farm base in China.However,the effects of large-scale onshore wind farms along the EAAF on multidimensional waterbird diversity,and how to mitigate these effects,remain unclear.Here we examined how wind farms and their surrounding landscapes affected multidimensional waterbird diversity along the Yellow Sea coast.Taxonomic,functional,and phylogenetic diversity of the waterbird assemblages,and mean pairwise distances and nearest taxon distances with null models were quantified in relation to 4 different wind turbine densities.We also measured 6 landscape variables.Multi-dimensional waterbird diversity(taxonomic,functional,and phylogenetic diversity)significantly decreased with increasing wind turbine density.Functional and phylogenetic structures tended to be clustered in waterbird communities,and environmental filtering drove waterbird community assemblages.Furthermore,waterbird diversity was regulated by a combination of wind turbine density and landscape variables,with edge density of aquaculture ponds,in addition to wind turbine density,having the greatest independent contribution to waterbird diversity.These results suggest that attempts to mitigate the impact of wind farms on waterbird diversity could involve the landscape transformation of wind farm regions,for example,by including high-edge-density aquaculture ponds(i.e.,industrial ponds)around wind farms,instead of traditional low-edge-density aquaculture ponds.

TRiceR: A Web Application for Supporting Risk Assessment of Ice Falling from Wind Turbine Blades

In regions with high population densities, the development of wind energy projects situated in an industrial environment or close to cities is a preferred option, since it represents some major advantages. On the other hand, it also represents a drawback in terms of safety during winter conditions. Ice accretion on the wind turbine blades represents a major risk as ice fall may cause incidents, even lethal accidents to people in the vicinity. The current common methodology to identify the potentially risky areas around wind turbines uses a deterministic approach which leads to excessively large zones around the turbines without granularity or circumstantial sub-zones. The approach presented in this paper is a probabilistic risk-based Monte Carlo methodology associated with an acceptance framework. Developed by Engie Tractebel, this methodology allows a much more detailed mapping of the risk zones and also enables to model the impact of mitigating measures. This represents a real risk-based decision tool for windfarm developers and operators. The approach is fully compliant with the IEA (International Energy Agency) Wind “International Recommendations for Ice Fall and Ice Throw Risk Assessments” and recent international safety standards. The tool is available as a cloud-based application called TRiceR.

Estimates of N_2O Emissions and Mitigation Potential from a Spring Maize Field Based on DNDC Model

Agricultural production plays an important role in affecting atmospheric nitrous oxide （N20） concentrations. Field measurements were conducted in Dalian City, Liaoning Province in Northeast China from two consecutive years （2009 and 2010） to estimate NzO emissions from a spring maize field, a main cropping system across the Chinese agricultural regions. The observed flux data in conjunction with the local climate, soil and management information were utilized to test a process-based model, DeNitrification-DeComposition （DNDC）, for its applicability for the cropping system. The validated DNDC was then used for exploring strategies to reduce N20 emissions from the target field. The results showed that the major N20 pulse emissions occurred with duration of about 3-5 d after fertilizer application in both years 2009 and 2010, which on average accounted for about 60% of the total N20 emissions each year. Rainfall and fertilizer application were the major factors influencing the N20 emissions from spring maize field. The average N20 flUXeS from the CK （control plot, without fertilization） and FP （traditional chemical N fertilizer） treatments were 23.1 and 60.6 gg m-2 h-~ in 2009, respectively, and 21.5 and 64.3 gg m-2 h-~ in 2010, respectively. The emission factors （EFs） of the applied N fertilizer （270 kg N ha-1） as N20- N were 0.62% in 2009 and 0.77% in 2010, respectively. The comparison of modeled daily NzO emission fluxes against observations indicated that the DNDC model had a good performance even if without adjusting the internal parameters. The modeled results showed that management practices such as no-till, changing timing or rate of fertilizer application, increasing residue incorporation, and other technically applicable measures could effectively reduce N20 emissions from the tested fields. Our study indicated that avoiding application of N fertilizers at heavy rainfall events or splitting the fertilizer into more applications would be the most feasible approaches to reduce N20 emissions from spring maize production in Northeast China.

Microtremor-based analysis of the dynamic response characteristics of earth-fissured sites in the Datong basin, China

This study conducted microtremor testing along six survey lines that cross three typical earth fissures in the Datong basin to determine the dynamic response characteristics of earth fissure sites with regard to the Fourier amplitude spectrum,response spectrum,and Arias intensity.The results show the following.(1)The predominant frequency of an earth fissure site is mainly affected by the thickness and the shear wave velocity of the soil layer and is minimally effected by the presence of an earth fissure.(2)Earth fissures have a pronounced amplification effect on dynamic response.Fourier amplitude,response acceleration,and Arias intensity are high near an earth fissure and decrease with an increase in distance from the earth fissure,tending toward stability at a distance of 20 m.(3)The area that is seriously affected by this amplification is within 6-8 m of an earth fissure,and the general affected area is farther out than this,to a distance of 25 m.(4)New construction should be avoided in an area affected by the amplification,and existing buildings in general and seriously affected areas need to be reinforced to increase their seismic fortification intensity.

Qinghai-Tibet Expressway experimental research

As one part of the National Highway Network Planning in China, the Qinghai-Tibet Expressway （QTE） from Golmud to Lhasa will be built in the interior of the Qinghai-Tibet Plateau （QTP） across about 630 km of permafrost lands. Due to the problematic interactions between the engineering foundations and permafrost, the frozen-soil roadbed of the QTE will be subjected to the more intense thermal disturbances due to the wider black surface. The design and construction for long-term thermal and mechanical stability will face more severe challenges than those in ordinary highways and railways in the same region. In order to provide scientific support for cold regions engineering practices, the QTE Experimental Demonstration Project （EDP） was constructed in situ in the vicinity of the Beilu＇he Permafrost Station in the interior of the QTP. In this paper, the anticipated problems of the proposed QTE project are enumerated, and the structures of the test sections for QTE EDP are described. Through numerical simulations, it was found that the heat transfer processes occurring in each specific road structure are significantly different. The heat accumulation in the highway embankment is mainly due to the black bituminous pavement, but in the railway embankment with its gravel surfaces, it mainly comes from the side slopes. As a result, the net heat accumulation of the highway embankment is three times higher than that in the railway. In expressway, the heat accumulation is further increased because of the wider pavement so that significantly more heat will be accumulated in the roadbed beneath the centerline area. Thus, the thermal stability of the fro- zen-soil roadbed and the underlying permafrost of the QTE can be seriously threatened without proper engineering measures protection against thawing. Based on research and practical experiences from the operating Qinghai-Tibet Railway （QTR） and the Qinghai-Tibet Highway （QTH）, combined with the predicted characteristics of heat transfer in an expressway embankment, nine kinds of engineering measures for mitigating the thaw settlement of foundation soils through the cooling the roadbed soils were built and are being tested in the EDP. The design of the monitoring system for the EDP and the observed parameters were also described.

Disaster risk reduction in mountain areas: a research overview

This paper gives an account of the diverse dimensions of research on disaster risk reduction in mountain regions derived from an open call of the Journal of Mountain Science that brought 21 contributions.This special issue includes topics as diverse as landslide dynamics and mechanisms,landslide inventories and landslide susceptibility models,insights to landslide hazards and disasters and mitigation measures,disaster response and disaster risk reduction.The overall structure of the paper takes the form of three sections.The first part begins by laying out the significance of disaster risk reduction in mountain areas,whereas the second one looks at the research insights on disaster risk reduction in mountains provided by the contributions comprised in the special volume.The final section identifies areas for further research.

Comparative Study on Debris Flow Initiation in Limestone and Sandstone Spoil

Large spoil tips from reconstruction works as a result of the Wenchuan Earthquake in China are new debris flow hazards to the human society.However,there is a lack of detailed comparative study on debris flow initiation in different spoil materials.This paper describes a series of tests and analyses on debris flow characteristics(initiation,scale and mechanism) at six sites with limestone and sandstone materials near the Dujiangyan area.Research shows the limestone spoil contains debris flow prone clay content with high concentration of montmorillonite(highly expandable).In addition,limestone spoil is of such a low permeability that water mainly concentrates in the upper surface layer.Those factors make it easy for the increase of pore water pressure,decline of internal friction and conhesion force,leading to the occurence of large debris flows.In contrast,the sandstone spoil is less problematic and causes no major debris flow threats.Based on our research on the mechanism,the"stereometric drainage"method is sucessfully applied to control limestone spoil debris flows.

Risk Analysis for Mega Shopping Mall Projects in Egypt

Mega shopping mall projects have seen dramatic growth and great development in recent years in Egypt. Many new mega shopping mall projects are under construction and expecting to start working in the few coming years. In the absence of researches studying the Egyptian mega shopping mall projects, this study tries to highlight the most critical risks that face these projects and the associated most effective response methods to be employed. The scope covers the analysis from different perspectives by including owners/developers, designers, consultants, project managers, and contractors that have previous experience in large-scale projects such as shopping mall projects. In this study, 30 construction project risks are classified into six main categories according to their type and 150 risk mitigation/elimination measures are introduced to overcome the impact of risks under each of these risk categories. The results reveal that the main risk category that faces the mega shopping mall projects in Egypt is the one including the financial risk factors. The most critical risk factor that faces these projects is the financial ability of the client. These results are similar to findings by previous researches conducted for large projects in other countries.

Security Threads and IoT Security

One of the technologies that have attracted the most attention recently across a variety of applications is the Internet of Things (IoT). The Internet of Things (IoT) is the combination of sensor, embedded computing, and communication technologies. The goal of the Internet of Things is to provide seamless services to anything, everywhere, at any time. The internet of things (IoT) technologies plays a vital role everywhere after the internet and information and communication technology, ushering in the fourth disruptive technology revolution (ICT). For real-time processing, communication, and monitoring, the smart items are linked together through wired or wireless connections. Implementing the IoT system presents security and privacy challenges since IoT devices are incompatible with current security standards based on tradition. This paper discusses IoT security strands, mitigation strategies, and privacy issues. This study’s major objective is to get more knowledge about security threats, mitigation techniques, and privacy concerns in IoT devices. The authors also mentioned a few cutting-edge technologies that can address general security problems. This study’s major objectives are to find research gaps in IoT security and match solution paradigms. The advent and rapid growth of the Internet of Things (IoT), which offers innumerable benefits, facilities, and applications including smart grids, smart homes, smart cities, and intelligent transportation systems (ITS), have an impact on everyone’s life. However, the deployment and use of sensing devices exposes IoT-based systems and applications to many security flaws and attacks. Furthermore, the lack of standardization brought on by the diversity of devices and technologies makes integrating security in the IoT a severe problem. The purpose of this review paper is to highlight the numerous security threats, challenges, and attacks that IoT-enabled applications face.

Sustainability of Bridges:Risk Mitigation for Natural Hazards

Bridges serve as essential parts of transportation infrastructure,facilitating the movement of people and goods across rivers,valleys,and other obstacles.However,they are also susceptible to a wide range of natural hazards,including floods,earthquakes,and landslides,which can damage or even collapse these structures,leading to severe economic and human losses.A risk index has been developed to address this issue,which quantifies the likelihood and severity of natural hazards occurring in a specific location.The application of risk indices for natural hazards in bridge management involves a data collection process and mathematical modelling.The data collection process gathers information on bridges’location,condition,and vulnerability,while mathematical modelling uses the data to assess the risk of natural hazards.Overall,risk indices provide a quantitative measure of the vulnerability of bridges to natural hazards and help to prioritize maintenance and repair activities.Mitigation measures are then evaluated and implemented based on the risk assessment results.By using this tool,the UBMS research group has developed an algorithm for risk assessment which will be essential in the decision-making process,specifically focused on enhancing Fund Optimization,Deterioration Modelling,and Risk Analysis.These developments effectively fulfill the primary objectives associated with addressing and mitigating hazards.This development also helps bridge managers understand the potential threats posed by natural hazards and allocate resources more efficiently to ensure the safety and longevity of critical transportation infrastructure.

Simulation and study on mitigation measures of frequent subsynchronous oscillation with low amplitude at multi-power plants

Subsynchronous oscillation (SSO) with low amplitude that exceeds cumulative fatigue threshold of the generator shaft frequently could significantly reduce the shaft's service life, which is a new SSO problem that emerges in recent years. According to the real recording oscillograph, the basic reason for frequently over-threshold SSO with low amplitude at multi-power plants was analyzed based on Hulunbuir League system. The sensitivities of the electrical damping to the main electrical parameters in the contributing loop of subsynchronous torsional interaction were calculated. Based on the sensitivities, a simulation method was presented, which was used to excite the same oscillation as the actual case by exerting disturbance on the firing angle. The limitation of wide-band and narrow-band supplementary subsynchronous damping controller (SSDC) for mitigating this kind of SSO was analyzed based on the electromagnetic transient simulation model of Hulunbuir League system. The difference of supplementary excitation damping controller (SEDC) and parallel-form FACTS connected to the generator terminal was compared from the aspects of response time and the ability of damping torque supplying. The analysis indicates that their response time is similar but FACTS has stronger ability of damping torque supplying than SEDC. Time-domain simulation method was used to compare the mitigation effects of SEDC, static var compensator (SVC) and static synchronous compensator (STATCOM). Considering the mitigation effect, the floor space limit of the power plant and so on, STATCOM was considered as the best mitigation measure. A control strategy of cascaded STATCOM for engineering application was presented and the capacity for SSO mitigation as well as output characteristics was analyzed. The analysis indicates that STATCOM using the proposed control strategy has better mitigation effect and output characteristics with smaller capacity.