scholarly journals Modeling as a Tool for Transboundary Aquifer Assessment Prioritization

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2685
Author(s):  
Ashley E. P. Atkins ◽  
Saeed P. Langarudi ◽  
Alexander G. Fernald

Transboundary aquifers are critical global water supplies facing unprecedented threats of depletion; existing efforts to assess these resources do not adequately account for the complexities of transboundary human and physical system interactions to the determinant of the impact of assessment outcomes. This study developed a system dynamics model with natural, human, and technical system components for a section of the transboundary Mesilla Basin/Conejos-Médanos aquifer to evaluate the following dynamic hypothesis: how and when information from a transboundary aquifer assessment is reported and perceived, in scenarios where two countries follow identical and different timeframes, dynamically impacts the behaviors of the shared aquifer. Simulation experiments were conducted to quantitatively assess the dynamics of transboundary aquifer assessment information reporting and perception delays. These critical feedbacks have not previously been incorporated practically in simulation and analysis. Simulation results showed that the timing and content of reporting can change the dynamic behavior of natural, human, and technical components of transboundary aquifer systems. This study demonstrates the potential for modeling to assist with prioritization efforts during the data collection and exchange phases to ensure that transboundary aquifer assessments achieve their intended outcomes.

Author(s):  
J. Bradley Morrison ◽  
Robert L. Wears

AbstractWe build a system dynamics model based on a conceptual model originally proposed by safety scientist Jens Rasmussen to explore the dynamics of a safety system subject to pressures for performance improvement. Rasmussen described forces that generate a drift in the boundary of acceptable performance that can push the organization towards “flirting with the margin” and thus operate at very high risk of catastrophic safety failure. Simulations of the model faithfully replicate the behavior described by Rasmussen and others in a variety of scenarios. Simulation experiments further illuminate the potential for risky behavior and point towards some approaches to better system safety.


2019 ◽  
Vol 11 (14) ◽  
pp. 3995 ◽  
Author(s):  
Roberto Pasqualino ◽  
Irene Monasterolo ◽  
Aled Jones

In 1972, The Limits to Growth, using the World3 System Dynamics model, modeled for the first time the long-term risk of food security, which would emerge from the complex relation between capital and population growth within the limits of the planet. In this paper, we present a novel system dynamics model to explore the short-term dynamics of the food and energy system within the wider global economic framework. By merging structures of the World3, Money, and Macroeconomy Dynamics (MMD) and the Energy Transition and the Economy (ETE) models, we present a closed system global economy model, where growth is driven by population growth and government debt. The agricultural sector is a general disequilibrium productive sector grounded on World3, where capital investment and land development decisions are made to meet population food need, thus generating cascade demands for the energy and capital sector. Energy and Capital Sectors employ a more standard economic approach in line with MMD and ETE. By taking into account the role of financial, real, and natural capital, the model can be used to explore alternative scenarios driven by uncertainty and risk, such as climate extreme events and their impacts on food production. The paper presents scenario analysis of the impact of an exogenous price, production, and subsidies shock in the food and/or energy dimensions on the economic system, understanding the sources of potential cascade effects, thus providing a systemic risk assessment tool to inform global food security policies.


2019 ◽  
Vol 11 (21) ◽  
pp. 6045 ◽  
Author(s):  
Qiang Yan ◽  
Simin Zhou ◽  
Xiaoyan Zhang ◽  
Ye Li

In this paper, we build a causal interaction diagram between the factors that may influence the sales and profits of online stores. An online store’s real operation data were used to help determine the causal relationship between variables. Finally, we proposed a system dynamics model and conducted a simulation of the operation of an online store. In this model, we focused on the impact of promotion and positive/negative electronic word of mouth (e-WOM) on the sales and profits of the online stores. The simulation results showed a similar trend to the real data and the main research finding showed that promotion is not a long-term measure for the sustainable development of online stores. Excessive promotion effort may lead to consumers’ dissatisfaction leading the increase of negative e-WOM. The systematic simulation can help us understand better the long-term effect of promotion and e-WOM on the operation of online stores. Finally, we gave some management suggestions for online stores’ sustainable operations.


2014 ◽  
Vol 989-994 ◽  
pp. 1328-1332
Author(s):  
Xiu Li Gao ◽  
Tian Jun Hu ◽  
Peng Peng

This paper discusses the connotation of urban low-carbon transport in detail, on the basis of the analysis of low-carbon transport. Combined with the relationship among urban low-carbon transport system elements, the article establishes the system dynamics model. Finally, it simulates the development trends of low-carbon transport in Beijing in the future, and compares the simulation results of different traffic schemes. Moreover, the study puts forward the concrete policy simulations to improve urban low-carbon transport.


2013 ◽  
Vol 437 ◽  
pp. 590-596
Author(s):  
Xi Jian Zheng ◽  
Lei Ma ◽  
Yu Fei Zhu

Roll number and rolling schedule are the important parameters affecting the quality of steel bar straightening,when domestic manufacturer design the straightening equipment, these two parameters design basic is by analogy, so it is necessary to study these two parameters. This paper calculated the straightening roller to obtain reasonable roll number; next step quantitative calculate to obtains the theory rolling schedule, in the meantime actual measurement to obtains the practical rolling schedule of the same equipment;then based on rigid-flexible virtual prototype technology to build straightening system dynamics model. At the theory rolling schedule, and the practical rolling schedule for steel bar straighten emulation, obtained straightness and deviation of different diameter steel bar after straightening. By comparison and analysis the simulation results, we obtain the reasonable roll number and rolling schedule. In this paper, this method have reference value to design the roll number and rolling schedule for similar straightening equipment.


10.31355/35 ◽  
2018 ◽  
Vol 2 ◽  
pp. 131-144
Author(s):  
Daniel Mirimo ◽  
Mad Nasir Shamsudin

NOTE: THIS ARTICLE WAS PUBLISHED WITH THE INFORMING SCIENCE INSTITUTE. Aim/Purpose................................................................................................................................................................................................. This research paper attempts to assess how the Malaysia rice industry will behave if and when certain changes occur, such as the removal of policies which affect its rice import price (namely the Vietnam rice floor export price and Thailand rice pledging scheme) and which result from the ongoing region economic integration embodied in ASEAN Vision 2020. Background................................................................................................................................................................................................... Malaysia rice farming sector compared to its ASEAN neighbors has a lower comparative advantage, this is transpiring in the lowering of the rice self-sufficiency targets and levels, moreover it is characterized as less efficiently managed compared to industrial farms. Therefore, Malaysia will continue to be a net importer of rice. It is against the background that this research was done, to anticipate how the Malaysia rice industry would behave if and when the existing trade barriers in the ASEAN rice market are removed and for the adjustment of Malaysia rice farming parameters to meet the desired state of rice self-sufficiency level. Methodology................................................................................................................................................................................................. A system dynamics model of Malaysia rice sector with consideration of its rice import prices from ASEAN trade partners was built and tested to check if it mimics real world behavior pattern. Nevertheless, the exercise in which the model built was purposed is to foresight, the ability to anticipate how the system will behave if and when certain changes occur and a tool for policy design, it is not forecasting and it does not depend on the ability to predict. Contribution................................................................................................................................................................................................. This study is in the line with previous related studies with the concern of the impact of trade liberalization on the global as well as ASEAN rice market, but the beauty of the methodology applied is into taking account of nonlinear relationship among variables of the system, the feedback loop mechanism, time delays, and the incorporation of all variables that are relevant to the problem endogenously. Thus the model simulation results are driven not by external factors, but by the internal structure of the model. The internal structure made of the feedback loos formed by the interdependency between variables. Findings....................................................................................................................................................................................................... Simulation results obtained from different Malaysia rice import price scenarios indicate a downtrend of the Malaysia rice self-sufficiency level and of less importance; the change is less than one percentage point. Recommendations for Practitioners.......................................................................................................................................................... Given the long run trend relationship between the rice import prices and the self-sufficiency levels, it may be advisable to policy makers to let the economic arguments for open trade with the risk of an increasing trend of import prices. It also prevails over the food security arguments, which might be involved in unintended consequences resulting from different forms of government intervention in the market. Recommendation for Researchers............................................................................................................................................................ There is a need to continue to conduct test based on new scenarios and model assumptions. New research to assess the impact of selected ASEAN countries price policies on Malaysia rice industry may produce different results and recommendations. For example if we assume these selected ASEAN countries price policies are moving towards a free trade orientation, as well as the Malaysia rice industry. Impact on Society......................................................................................................................................................................................... Food security is essential to the survival of the society. Thus, the supply of a staple commodity such as rice in Malaysia is essential to the social, political and economic stability of the society. Understanding the supply and demand conditions affecting the distribution of this product in the Country is critical for public and private policy making about the development of the economy and society. Rice commodity was conceptualized as a normal good in this study and we gained an insight on the rice consumption per capita behavior through different Malaysia rice import prices. What if the rice commodity is conceptually modeled as an inferior good, definitely rice consumption per capita behavior will change, with its associated impact on the economy and society. This study enables us to investigate the possible outcomes for various scenarios. Future Research.............................................................................................................................................................................................. For further research, this system dynamics model of Malaysia rice industry can be improved by including some variables closely related to trade such as the exchange rate between the United States dollar and ASEAN countries currency and the oil price, some variables which can affect the rice production such as the climate change and some variables on the rice consumers side such as the changing consumer preferences (normal Vs inferior commodity), or on the rice/paddy farmers side such as poverty alleviation.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Zili Tai ◽  
Ji Guo ◽  
Yeli Guan ◽  
Qingquan Shi

Since the end of 2019, the outbreak of COVID-19 has severely affected port production and operation. There is little research on the systematic impact assessment. This study took Shanghai Port as an example and evaluated the impact under different scenarios through establishing a System Dynamics model. It is found that the epidemic mainly has a greater impact on passenger transport, but less on cargo transport. The ports with the function of transportation in highway, railway, and waterway were the key nodes in the international logistics network. More attention should be paid to the impact assessment of COVID-19 on ports’ production and operation. It is necessary to strengthen the port’s collection and distribution capabilities, improve port production efficiency, and further strengthen port modernization. This research method proposed in this paper can provide a reference for the impact assessment of similar events, and the empirical results can provide a reference for handling the epidemic shock for the port and shipping departments.


2020 ◽  
Vol 12 (16) ◽  
pp. 6511
Author(s):  
Mudhafar Alefari ◽  
Mohammed Almanei ◽  
Konstantinos Salonitis

Employee performance is dynamic and can have great impact on the overall performance of any company and its sustainability. A number of factors that can be controlled by the company can affect the employees’ performance. The present paper starts with a thorough literature review for identifying these key driving in order to develop a system dynamics models that will be able to assess different improvement scenarios and initiatives. Based on causal loop diagrams, stock and flow diagrams are developed and solved using system dynamics theory. The model developed can be used for organizations to assess the impact of different improvement initiatives.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaojing Liu ◽  
Tiru Arthanari ◽  
Yangyan Shi

PurposeThis paper examines the establishment of supply chain robustness against corruption by utilizing risk interactions.Design/methodology/approachBased on empirical results from the New Zealand dairy industry, a system dynamics model is established to explore the underlying relationships among variables.FindingsThe results show that although certain supply chain risks seem unrelated to corruption, their mitigation would help mitigate the impact of corruption due to risk interactions; and mitigation of some of the risks is more effective in mitigating the impact of corruption. Leverage risks have been defined and identified in this research, which expands the extant knowledge in reducing the impact of corruption on supply chains.Originality/valueThe research illustrates how the impact of corruption can be studied in an integrated way with dairy supply chain SD analysis. It is a pioneering study to mitigate the impact of corruption on supply chains from supply chain robustness.


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