scholarly journals Risk Assessment of Boot Hydropower Projects in Nepal Using Fuzzy Logic Approach

Author(s):  
Pramesh Tripathi ◽  
Santosh Kumar Shrestha

<p>Many Hydropower Projects in Nepal are carried out with insufficient risk assessment because of which time over run or variations are predominant. Many projects are stuck in preconstruction phase and others in construction phase. In this study all possible risks associated with the BOOT Hydropower Project in Nepal were identified and evaluated. Fuzzy rating tool has been used to quantify the risk associated with the BOOT Hydropower Projects in Nepal. It provides a flexible and easily understood way to analyze the project risks.  The relative importance (impact) of risk factors was determined from the survey results. A set of questionnaire was prepared for the survey. The survey was conducted with the experts that have experience in BOOT hydropower projects. From the survey, among the type of risks, Grid Connection / Power Evacuation, Political risk and Geological risk were found to be predominant risk respectively in BOOT hydropower projects in Nepal. The risk assessment method enabled a Risk Index (R) value to be calculated, establishing a 4-grade evaluation system: low risk having R values between 1.17 and 1.69; medium risk, between 1.69 and 2.08; high risk, between 2.08 and 2.47; extreme risk, between 2.47 and 2.78. Applicability of the methodology was tested on a real case hydropower project namely Middle Modi Hydroelectric Project (15.1 MW) which is in construction phase on Modi River in Western Region in Nepal and Madhya Bhotekosi Jalavidyut Company Ltd. (102 MW) which is also in construction phase on Bhotekoshi River in Central Region in Nepal.  The risk analysis method will give investors a more rational basis on which to make decisions and it can prevent cost and schedule overruns. An overall risk index can be used as early indicators of project problems or potential difficulties. Evaluators can keep track to evaluate the current risk level with the progress of investments.</p><p><strong>Journal of Advanced College of Engineering and Management</strong>, Vol. 3, 2017, Page: 115-125</p><p> </p>

Work ◽  
2021 ◽  
pp. 1-11
Author(s):  
Carlos Carvalhais ◽  
Micaela Querido ◽  
Cristiana C. Pereira ◽  
Joana Santos

BACKGROUND: The COVID-19 global pandemic brought several challenges to occupational safety and health practice. One of these is the need to (re)assess the occupational risks, particularly, biological risks. OBJECTIVE: The purpose of this work is to promote guidance to occupational safety and health practitioners when conducting a biological risk assessment in this context. METHODS: The main steps of the biological risk assessment are explained with some inputs regarding the novelty posed by SARS-CoV-2 and an example of a qualitative risk assessment method is presented. Also, its application to two different activities was exemplified. RESULTS: In both cases, the assessment considered that vulnerable workers were working from home or in medical leave. The results showed low or medium risk level for the assessed tasks. For medium risk level, additional controls are advised, such maintain social distancing, sanitize instruments/equipment before use, use proper and well-maintained PPE (when applicable), and promote awareness sessions to spread good practices at work. Employers must be aware of their obligations regarding biological risk assessment and OSH practitioners must be prepared to screen and link the abundance of scientific evidence generated following the outbreak, with the technical practice. CONCLUSIONS: This paper could be an important contribution to OSH practice since it highlights the need to (re)assess occupational risks, especially biological risk, to ensure a safe return to work, providing technical guidance.


Author(s):  
Cansu Dagsuyu ◽  
Murat Oturakci ◽  
Esra Sarac Essiz

In this study, a new approach to Fine-Kinney risk assessment method is developed in order to overcome the limitations of the conventional method with clustering algorithms. New risk level of classes are attempted to determine with K-Means and Hierarchical clustering algorithms with using two different distance functions which are Euclidean and Manhattan distances. According to the results, K-Means algorithms have provided accurate and sensitive cluster of classes. Classes from conventional and K-Means algorithms are applied and compared to the identified risks of a workshop of a medium sized textile company. Results of the study indicate that clustering techniques are new, original and applicable way to define new classes in order to prioritize risks by overcoming the drawbacks of conventional Fine-Kinney method.


Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Yan Wang ◽  
Jie Su ◽  
Sulei Zhang ◽  
Siyao Guo ◽  
Peng Zhang ◽  
...  

In view of the shortcomings in the risk assessment of deep-buried tunnels, a dynamic risk assessment method based on a Bayesian network is proposed. According to case statistics, a total of 12 specific risk rating factors are obtained and divided into three types: objective factors, subjective factors, and monitoring factors. The grading criteria of the risk rating factors are determined, and a dynamic risk rating system is established. A Bayesian network based on this system is constructed by expert knowledge and historical data. The nodes in the Bayesian network are in one-to-one correspondence with the three types of influencing factors, and the probability distribution is determined. Posterior probabilistic and sensitivity analyses are carried out, and the results show that the main influencing factors obtained by the two methods are basically the same. The constructed dynamic risk assessment model is most affected by the objective factor rating and monitoring factor rating, followed by the subjective factor rating. The dynamic risk rating is mainly affected by the surrounding rock level among the objective factors, construction management among the subjective factors, and arch crown convergence and side wall displacement among the monitoring factors. The dynamic risk assessment method based on the Bayesian network is applied to the No. 3 inclined shaft of the Humaling tunnel. According to the adjustment of the monitoring data and geological conditions, the dynamic risk rating probability of level I greatly decreased from 81.7% to 33.8%, the probability of level II significantly increased from 12.3% to 34.0%, and the probability of level III increased from 5.95% to 32.2%, which indicates that the risk level has risen sharply. The results show that this method can effectively predict the risk level during tunnel construction.


2021 ◽  
Vol 11 (24) ◽  
pp. 11721
Author(s):  
Jianxiu Wang ◽  
Ansheng Cao ◽  
Zhao Wu ◽  
Zhipeng Sun ◽  
Xiao Lin ◽  
...  

Ultra-shallow-buried and large-span double-arch tunnels face complex risks during construction. The risk sources are hidden, complicated, and diverse. The dynamic risk assessment problem cannot be solved satisfactorily by using the static method as an insufficient amount of research has been conducted. The land part of the Xiamen Haicang double-arch tunnel was selected as the background for the dynamic risk assessment of ultra-shallow-buried and large-span double-arch tunnel construction. The construction process was divided into five stages: pre-construction preparation; ground and surrounding rock reinforcement; pilot tunnel excavation; and the single-and the double-tunnel excavations of the main tunnel. Through consultation with tunnel experts, six first-level and thirty second-level risk evaluation indexes were proposed. The benchmark weight of the dynamic risk assessment index was determined by using the analytic hierarchy process. The weight of the risk evaluation index was revised according to the monitoring data and the construction stage. The fuzzy evaluation matrix of the construction risk membership degree was obtained by using the fuzzy comprehensive assessment method, and the calculation results were analyzed using the subsection assignment method. Control measures were suggested according to the risk assessment results. The risk assessment result of the double tunnel excavation stage of the main tunnel was level II, and the risk level was the highest among the five construction stages. The risk assessment result of the ground and surrounding rock reinforcement stage was level IV, and the risk level was the lowest. The dynamic construction safety risk assessment based on the fuzzy comprehensive assessment method is more timely, accurate, and reasonable than the traditional assessment method. The method can be adopted in similar engineering projects.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
X. B. Gu ◽  
S. T. Wu ◽  
X. J. Ji ◽  
Y. H. Zhu

The debris flow is one of the geological hazards; its occurrence is complex, fuzzy, and random. And it is affected by many indices; a new multi-index assessment method is proposed to analyze the risk level of debris flow based on the entropy weight-normal cloud model in Banshanmen gully. The index weight is calculated by using the entropy weight method. Then, the certainty degree of each index belonging to the corresponding cloud is obtained by using the cloud model. The final risk level of debris flow is determined according to the synthetic certainty degree. The conclusions are drawn that the method is feasible and accurate rate of risk estimation for debris flow is very high, so a new method and thoughts for the risk assessment of debris flow can be provided in the future.


Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 219
Author(s):  
Jongsung Kim ◽  
Donghyun Kim ◽  
Myungjin Lee ◽  
Heechan Han ◽  
Hung Soo Kim

For risk assessment, two methods, quantitative risk assessment and qualitative risk assessment, are used. In this study, we identified the regional risk level for a disaster-prevention plan for an overall area at the national level using qualitative risk assessment. To overcome the limitations of previous studies, a heavy rain damage risk index (HDRI) was proposed by clarifying the framework and using the indicator selection principle. Using historical damage data, we also carried out hierarchical cluster analysis to identify the major damage types that were not considered in previous risk-assessment studies. The result of the risk-level analysis revealed that risk levels are relatively high in some cities in South Korea where heavy rain damage occurs frequently or is severe. Five causes of damage were derived from this study—A: landslides, B: river inundation, C: poor drainage in arable areas, D: rapid water velocity, and E: inundation in urban lowlands. Finally, a prevention project was proposed considering regional risk level and damage type in this study. Our results can be used when macroscopically planning mid- to long-term disaster prevention projects.


Agriculture ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 47 ◽  
Author(s):  
Haifang He ◽  
Longqing Shi ◽  
Guang Yang ◽  
Minsheng You ◽  
Liette Vasseur

Tea plantations have used many synthetic chemicals to ensure performance and control of pests. This has led to increased contamination of soils and reduced tea growth. We assessed the levels of heavy metals, including Cd, Cr, Pb, Cu, Ni, Zn, Hg, As, and pesticide residues, such as HCHs, biphenyl chrysanthemum ester, methamidophos, imidacloprid, permethrin, in the soil of tea plantations of Taiwan, Tibet, Guangdong, and Fujian. The Potential Ecological Risk Index and the Nemerow comprehensive pollution index were used to analyze the data. The results showed that risk indices in Tibet, Guangdong and Fuzhou were considered as moderate ecological harm level. Ecological risk assessment index of Anxi organic and Anxi conventional tea gardens suggested a “low” risk level. The Nemerow comprehensive pollution indices for soil pesticide residues in the tea plantations of Taiwan, Tibet, Anxi organic and Anxi conventional were considered mild. Guangdong and Fuzhou had values suggesting “slight pollution” levels. According to National Soil Environmental Quality Standard (GB15618-1995), soil in tea plantations in Taiwan, Tibet, and Anxi conventional matched the national first grade of soil quality and those from Guangdong, Fuzhou, and Anxi organic tea garden matched the national second grade.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1369 ◽  
Author(s):  
Qiang Fan ◽  
Zhong Tian ◽  
Wei Wang

Under the influence of extreme weather conditions or other unfavorable factors, if a dam break occurs in a mountain river, it will cause a great number of casualties and property losses in the affected downstream areas. Usually, early warning of the affected areas downstream of the dam depends mainly on qualitative evaluation and cannot be quantitatively evaluated. Based on the authors’ calculation of floods for many years, this study presents a quantitative assessment method for flood risk. The Ertan Hydropower Station in Southwest China and the flood-affected areas were chosen as the object of this study. Based on field surveys, research literature data, and the authors’ calculations, the basic data of the Ertan Hydropower Station and the calculation results of the dam break were obtained, and 35 representative flood-affected areas were selected to study risk assessment and early warning. The fuzzy analytic hierarchy process (FAHP) was used to build a mathematical model for quantitative analysis. The population, flood arrival time, flood level, evacuation time, and local GDP (Gross Domestic Product) were selected as five typical evaluation factors. Finally, this study calculated and counted the risk level of 35 representative flood-affected areas, and the study results were applied to Quxue and Guanmaozhou Hydropower Station.


2017 ◽  
Vol 13 ◽  
pp. 219-224 ◽  
Author(s):  
Anna A. Antsiferova ◽  
Vyacheslav A. Demin ◽  
Vladimir F. Demin

Results of the health risk (HR) assessment are needed to support decisions on safety of nanotechnologies and practical use of nanomaterials/nanoparticles (NMs/NPs), including establishment of health safety standards (HSSs). To meet these needs HR assessment’ tools are developed using the great experience in the development and application of such tools for other sources of harm (ionizing radiation, chemicals, etc.), accumulated during the last decades. The tools include methodology, computer data bases and calculation codes.Three-level’ scheme of development and application of HR assessment methodology is roposed: general, specific and simplified methods. The general method serves as a basis for development of specific methods, applicable to the concrete harm sources, for development and justification of simplified methods. In this approach the specific method consists of two parts: 1) the general HR assessment method, 2) exposure – response dependences for the harm source considered in the form of age-cause-specific death or diseases coefficients. Such structure of HR assessment methodology in its full development makes specific methods being more transparent and comparable as well as safety decisions based on HR assessment for different harm sources.The proposal is made concerning the special risk index for the risk standardization and comparison. The unified approach is developed to the establishment of the HSSs and other levels of decision-making on people safety with the use of HR risk assessment in different spheres of human activity including nanotechnology and use of NPs/NMs.


2011 ◽  
Vol 217-218 ◽  
pp. 734-739 ◽  
Author(s):  
Chongsin Sookoomjariyapong ◽  
Sanguan Vongchavalitkul ◽  
Sun Sayamipuk

The deterioration of reinforced concrete (RC) structure due to chloride attack plays an important role in the reduction of structure strength. Consequently, the actual condition of structure is an essential investigation for management planning in concrete structure which is attacked by chloride. In this paper, the proposed assessment bases on the risk management and the reliability theory presents in risk index (RI) of structure. The reinforced concrete building under the marine environment was an illustrative example for risk evaluation. It was found that the risk index of structure equaled to 20, it implied that the structural condition encountered with extreme risk due to chloride attack and must be rehabilitated urgently. As analysis results, the risk assessment is relation to the actual condition of structure. This assessment can be used as a guideline tool for structural engineering to assess the concrete structure attacked by chloride.


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