This paper presents a tool developed for the analysis of networks extracted from system dynamics models. The developed tool and the collected models were used and analyzed in the research paper, ...Review and structural analysis of system dynamics models in sustainability science 1. The models developed in Vensim, Stella, and InsightMaker are converted into networks of state-variables, flows, and parameters by the developed Python program that also performs model reduction, modularity analysis and calculates the structural properties of the models and its main variables. The dataset covers the results of the analysis of nine models in sustainability science used for policy testing, prediction and simulation.
Increasingly, modern conflict and military activity require soldiers to carry out their missions within foreign cultures in which the civilian populace rather than a battlefield becomes the focal ...point. So, from the commander to the soldier on the street, the warfighter must understand the society's values and the motivations of the groups within it. Gaming can help the military train soldiers for this new type of conflict.
Exploring future land use changes and assessing the habitat quality remains a challenging topic for watershed ecological sustainability. However, most studies ignore the effects of coupled climate ...change and development patterns. In this study, a framework for assessing habitat quality under the influence of future land use change is constructed based on exploring the driving forces of land use change factors and integrating the system dynamics (SD) model, future land use simulation (FLUS) model and InVest model. The framework enables the projection of land use change and the assessment of habitat quality in the context of future climate change and different development strategies. Applying the framework to the Weihe River Basin, the main driving forces of land-use change in the Weihe River Basin were identified based on geographical detectors, and habitat quality assessment was realized for the Weihe River Basin under the coupled scenarios of three typical shared socioeconomic pathways and future development patterns (SSP126-EP, SSP245-ND, SSP585-EG). The results show that 1) population, precipitation, and temperature are the major driving factors for land use change. 2) The coupling model of SD and FLUS can effectively simulate the future trend of land use change, the relative error is within 2 %, and the overall accuracy is 93.58 %. 3) Significant differences in habitat quality as a result of modifications in land use patterns in different contexts. Affected by ecological protection, the habitat quality in SSP126-EP was significantly better than that in SSP245-ND and SSP585-EG. This research can provide references for future watershed ecological management decisions.
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•A framework for future multiscenario habitat quality assessment was established.•Habitat quality change was assessed under three climate and development patterns.•Socioeconomic and meteorological elements are the main driving forces of land use.•Coordination between economic development and habitat quality should be emphasized.
Evaluation of climate change impacts (CCIs) on urban expansion is important to improving the urban sustainability in drylands. Taking the agro-pastoral transitional zone of northern China (APTZNC) as ...an example, this study evaluates potential CCIs on urban expansion in 2015–2050. First, we set up six climate change scenarios (CCSs) based on the simulated results of global climate model and regional climate model under different representative concentration pathways. Then, we simulate regional urban expansion under the different CCSs using the zoned Land Use Scenario Dynamics-urban (LUSD-urban) model. We find that climate change will be a key factor that affects urban expansion in this region. The urban land affected by climate change in the entire region will increase from 20.24–26.48 km2 (2020) to 119.71–339.26 km2 (2050), an increase of 4.91–11.81 times. The CCIs on urban expansion will be the most significant in the mid-western region. In 2050, the urban land potentially affected by climate change will be 98.70–213.88 km2, which is 42.26%–134.12% of the urban land in the entire region. To improve urban sustainability in the APTZNC, effective measures must be adopted to mitigate and adapt to CCIs on urban expansion.
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•The impacts of climate change on urban expansion in APTZNC in 2015–2050 are evaluated.•The climate change would be a key factor affecting the urban expansion in this region.•The urban land affected by climate change would rise by 5–12 folds.•The impacts would be the most significant in the mid-western sub-region of APTZNC.•The zoned LUSD-urban model can more effectively simulate the urban expansion.
Carbon neutrality goal puts forward new requirements for the energy structure of the power industry in China. The impact of electricity marketization reform on energy transition is one key issue that ...we need to consider. This paper constructs a system framework for the internal connection of the four primary energy sources and two system dynamics (SD) models to analyze the impact of the marketed on-grid price on the energy transition in the power industry. The results show that: (1) Compared with the benchmark on-grid price, the marketed on-grid price can promote the realization of the energy transition goal in the power industry to a certain extent. In 2060, the marketed on-grid price will be stable at about 0.1 yuan/kWh. (2) The energy transition goal can be achieved if the degree of market openness exceeds 60%. However, if coal-based power fully enters the marketization stage, the proportion of renewable energy can even reach more than 90% in 2060. (3) It is difficult to achieve the carbon neutrality goal only by increasing the proportion of renewable energy. Finally, we put forward corresponding policy recommendations.
•The electricity marketization reform has an impact on the energy transition.•Driving mechanism of the marketed on-grid price is investigated in the power industry.•Two system dynamics models are built.•The energy transition goal can be achieved if the market openness exceeds 60%.
Pigmeat is the most consumed red meat globally and consumption is expected to continue to increase. The sector is faced by the risk of epidemic and endemic disease impacts and other adverse ...influences. The aim of this study was to develop a dynamic simulation model of pig growing and finishing that can be used to model the financial and economic impacts of a variety of scenarios both related to disease effects and other influences on production. The model consists of a physical performance module and financial performance module. The core of the physical performance module comprises three stocks to model the flow of pigs from purchase to slaughter. Mortality rates, daily live weight gain and feed conversion ratios influence the dynamics of the physical performance. Since contracts between farmers and slaughterhouses often include large price penalties for over- and underweight pigs, carcase weight distribution is an important determinant of revenues. The physical performance module, therefore, simulates slaughter weight variations. The financial performance module calculates revenue, costs and gross margins. The revenue calculations take into account price penalties for over- and underweight pigs. To demonstrate the capabilities of the model, we apply the model to assess the economic consequences of production impacts associated with respiratory disease. We use estimated production impacts associated with respiratory disease from a study of all-in-all out growing and finishing systems based on pig production data and information from slaughterhouse monitoring in the UK. Our model suggests a reduction in the gross margin of nearly 40 % as a consequence of the estimated production impacts associated with a 10% increase in respiratory disease prevalence. Due to the lack of reliable information on slaughter weight variation, we also simulate the model using different assumptions about the slaughter weight distribution. An increase in the standard deviation of carcase weights from 8 kg to 12 kg, holding average weights constant, more than halves gross margins under our scenarios. We suggest that for all-in-all-out systems, carcase weight variation is likely to be a substantial factor in reducing income in the presence of respiratory disease and the economic impact of respiratory disease may be underestimated if the effects of disease on variation in carcase weights are not included in any analysis.
•A flexible modeling tool for physical and financial performance of pig production.•Variation in carcase weights is important due to common contract arrangements.•Respiratory disease is estimated to decrease gross margins by nearly 40 %.
This paper presents a decision-support system based on a system dynamics model designed to examine tourism management in the Galapagos Islands. A participatory approach was used to integrate the ...views of multiple stakeholders in the Galapagos Islands and to build an understandable, graphical representation of the impacts of tourism and residential population growth. Each subsystem is examined through hypotheses involving three scenarios of tourism growth that are associated with different residential population expansions. A number of integrative and linked social-ecological effects in our model have been shown to severely shock the natural environment of the Galapagos and saturate the capacity of several socio-economic subsystems. Major concerns of the expanding human dimension in the Galapagos are represented by (1) the growing number of introduced species that threaten the Islands' unique natural environment, and (2) the rapid saturation of the Galapagos National Park's tourism reception capacity. The model relies upon real data to specify rules, relationships, and rates of exchange that are derived through statistical functions and/or functions specified in theory or practice. The presented decision-support system is a quantitative scenario-planning tool that can be used by policy-makers to achieve an enhanced understanding of the Galapagos Islands as a coupled human-natural system.
This study delves into the intricate dynamics of tourism-induced water pollution through a systematic literature review, aiming to unravel complexities using a system dynamics (SD) modeling approach ...coupled with the PRISMA analysis methodology. Employing a comprehensive PRISMA analysis of 68 pertinent articles, the study establishes a metamodel for comprehending plastic pollution in water ecosystems resulting from tourism. The methodology emphasizes economic and environmental dimensions, causal conditions, and interventions, with a specific focus on the role of Information and Communication Technology (ICT). The results highlight integrated strategies as crucial in mitigating tourism-induced water pollution. These strategies advocate for the incorporation of environmental conservation and sustainable management practices. The study underlines the pivotal role of environmental education, awareness, and investments in protection as effective interventions. The findings offer valuable insights for policymakers and stakeholders in the tourism industry, emphasizing the necessity for proactive planning and management. The study advocates for knowledge-based decision-making to optimize tourism's environmental impacts and underscores the significance of quick and flexible responses to environmental challenges.
Increasing prevalence of endemic chronic kidney disease of unknown etiology (CKDu) in Sri Lanka is a major health problem since the 1990s. Despite numerous studies on CKDu, research groups have been ...unable to develop a comprehensive approach to mitigate the disorder, and thereby to identify research gaps. We conducted a systematic literature review of 119 publications on CKDu in Sri Lanka from Pubmed, Google Scholar, and Scopus, published until end September 2020. A higher CKDu prevalence in the working population of the North Central Province was reported with recent studies indicating patients from non-endemic regions as well. A majority were etiological studies that recorded conflicting and inconclusive evidence on CKDu etiology. Studies on clinico-pathological, diagnostic, biochemical, and molecular biological aspects of CKDu, studies analyzing CKDu symptom burden, anthropological, and behavioral impacts of CKDu, were reviewed as well. A dearth of research exists on nutritional, demographical, immunological, and microbial aspects of CKDu. The overview of the reviewed literature indicated the absence of a comprehensive plan of action to mitigate this situation. Hence, we propose the “One Health” approach with a systems dynamics model as a potential way forward to alleviate the CKDu epidemic in Sri Lanka. This enables the representation of multiple causative agents (and interactions thereof) among environmental, animal, and human systems, in concert with the “exposome” that provides the totality of exposure the individual has undergone since birth.
COVID-19 has prompted the extensive use of computational models to understand the trajectory of the pandemic. This article surveys the kinds of dynamic simulation models that have been used as ...decision support tools and to forecast the potential impacts of nonpharmaceutical interventions (NPIs). We developed the Values in Viral Dispersion model, which emphasizes the role of human factors and social networks in viral spread and presents scenarios to guide policy responses.
An agent-based model of COVID-19 was developed with individual agents able to move between 3 states (susceptible, infectious, or recovered), with each agent placed in 1 of 7 social network types and assigned a propensity to comply with NPIs (quarantine, contact tracing, and physical distancing). A series of policy questions were tested to illustrate the impact of social networks and NPI compliance on viral spread among (1) populations, (2) specific at-risk subgroups, and (3) individual trajectories.
Simulation outcomes showed large impacts of physical distancing policies on number of infections, with substantial modification by type of social network and level of compliance. In addition, outcomes on metrics that sought to maximize those never infected (or recovered) and minimize infections and deaths showed significantly different epidemic trajectories by social network type and among higher or lower at-risk age cohorts.
Although dynamic simulation models have important limitations, which are discussed, these decision support tools should be a key resource for navigating the ongoing impacts of the COVID-19 pandemic and can help local and national decision makers determine where, when, and how to invest resources.
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