Developing a resilient, robust and efficient supply network in Africa

PurposeSupply chains need to balance competing objectives; in addition to efficiency, supply chains need to be resilient to adversarial and environmental interference and robust to uncertainties in long-term demand. Significant research has been conducted designing efficient supply chains and recent research has focused on resilient supply chain design. However, the integration of resilient and robust supply chain design is less well studied. The purpose of the paper is to include resilience and robustness into supply chain design.Design/methodology/approachThe paper develops a method to include resilience and robustness into supply chain design. Using the region of West Africa, which is plagued with persisting logistical issues, the authors develop a regional risk assessment framework and then apply categorical risk to the countries of West Africa using publicly available data. A scenario reduction technique is used to focus on the highest risk scenarios for the model to be tractable. Next, the authors develop a mathematical model leveraging this framework to design a resilient supply network that minimizes cost while ensuring the network functions following a disruption. Finally, the authors examine the network's robustness to demand uncertainty via several plausible emergency scenarios.FindingsThe authors provide optimal sets of transshipment hubs with varying counts from 5 through 15 hubs. The authors determine there is no feasible solution that uses only five transshipment hubs. The authors' findings reinforce those seven transshipment hubs – the solution currently employed in West Africa – is the cheapest architecture to achieve resilience and robustness. Additionally, for each set of feasibility transshipment hubs, the authors provide connections between hubs and demand spokes.Originality/valueWhile, at the time of this research, three other manuscripts incorporated both resilience and robustness of the authors' research unique solved the problem as a network flow instead of as a set covering problem. Additionally, the authors establish a novel risk framework to guide the required amount of redundancy, and finally the out research proposes a scenario reduction heuristic to allow tractable exploration of 512 possible demand scenarios.

Seismic fragility functions for a pervasive unique form of construction with very high potential for social losses in Trinidad and Tobago: Two-story houses

The twin-island republic of Trinidad and Tobago is fortunate to have a long history of abundance of natural resources resulting in its being a major source of economic support for the English-speaking sovereign states of the Caribbean. The economic stability of the Caribbean is threatened, via a domino effect, by the current prevalent form of residential structures in Trinidad and Tobago because of a lack of conformity with proper seismic design in an earthquake-prone region (SS of 1.1 g–1.8 g). Continuing from a previous study of single-story houses in Trinidad and Tobago, fragility functions for three types of typical two-story residential structures were derived using Incremental Dynamic Analysis considering both aleatory and epistemic uncertainties. The selected ground motion records are compatible with spectra derived for Trinidad and Tobago. Fragility functions for the structures are with respect to limit states of slight, moderate, extensive, and complete damage as well as out-of-plane dynamic instability. These fragility functions can be used for regional risk assessment hence the derivation of disaster mitigation and management plans thereby avoiding a major crisis in the Caribbean.

Regional risk assessment of acid sulfate soil acidification under climate change based on mechanistic modelling of pyrite oxidation during prolonged drought events

<p>Under changing climate conditions with expected higher risks on long periods of severe drought events, acid sulfate soils have a higher risk for acidification when exposed to oxygen under a falling water table. A regional or continental risk map for acidification under possible future climate scenarios is one of the tools for evaluating agricultural, economic and environmental impacts of acidification. The starting point is a simulation model with the relevant processes accounting for (i) the effect of changing meteorological boundary conditions on the water dynamics inside the soil and the ground water depth, (ii) diffusion of oxygen inside the soil profile, and (iii) kinetic dissolution of pyrite and geochemical alterations. The simulation tool HPx (Jacques et al., 2018) couples all these processes and enables to evaluation of different model structures. Numerical results were compared to an extreme drought event in the lower Murray River region, Murray-Darling Basin South Australia, between 2007 and 2010. A second step was the implementation of the mechanistic model in a spatial framework using python. As a proof of principle, we started with 5 x 5 km grid in areas with high probability of acid sulfate soils. Soil spatial data was pre-processed to determine model hydraulic parameters using pedotransfer functions. Climate and soil data were defined for each grid cell and formatted at run time for input into HPx. HPx simulations are controlled for the specific data for each grid cell. The final step is to perform the simulations on large spatial and temporal scales using supercomputing for which a linux-version of HP1 was developed. These developments open up new opportunities for coupled soil-climate modelling.</p> <p>Jacques, D., Simunek, J., Mallants, D. and van Genuchten, M.T. (2018). JOURNAL OF HYDROLOGY AND HYDROMECHANICS 66, 211-226</p>

Multidisciplinary approach to COVID-19 risk communication: a framework and tool for individual and regional risk assessment

The COVID-19 pandemic has exceeded over sixty-five million cases globally. Different approaches are followed to mitigate its impact and reduce its spreading in different countries, but limiting mobility and exposure have been de-facto precautions to reduce transmission. However, a full lockdown cannot be sustained for a prolonged period. An evidence-based, multidisciplinary approach on risk zoning, personal and transmission risk assessment in near real-time, and risk communication would support the optimized decisions to minimize the impact of coronavirus on our lives. This paper presents a framework to assess the individual and regional risk of COVID-19 along with risk communication tools and mechanisms. Relative risk scores on a scale of 100 represent the integrated risk of influential factors. The personal risk model incorporates age, exposure history, symptoms, local risk and existing health condition, whereas regional risk is computed through the actual cases of COVID-19, public health risk factors, socioeconomic condition of the region, and immigration statistics. A web application tool (http://www.covira.info) has been developed, where anyone can assess their risk and find the guided information links primarily for Nepal. This study provides regional risk for Nepal, but the framework is scalable across the world. However, personal risk can be assessed immediately from anywhere.

Disaster Risk Management Through the DesignSafe Cyberinfrastructure

DesignSafe addresses the challenges of supporting integrative data-driven research in natural hazards engineering. It is an end-to-end data management, communications, and analysis platform where users collect, generate, analyze, curate, and publish large data sets from a variety of sources, including experiments, simulations, field research, and post-disaster reconnaissance. DesignSafe achieves key objectives through: (1) integration with high performance and cloud-computing resources to support the computational needs of the regional risk assessment community; (2) the possibility to curate and publish diverse data structures emphasizing relationships and understandability; and (3) facilitation of real time communications during natural hazards events and disasters for data and information sharing. The resultant services and tools shorten data cycles for resiliency evaluation, risk modeling validation, and forensic studies. This article illustrates salient features of the cyberinfrastructure. It summarizes its design principles, architecture, and functionalities. The focus is on case studies to show the impact of DesignSafe on the disaster risk community. The Next Generation Liquefaction project collects and standardizes case histories of earthquake-induced soil liquefaction into a relational database—DesignSafe—to permit users to interact with the data. Researchers can correlate in DesignSafe building dynamic characteristics based on data from building sensors, with observed damage based on ground motion measurements. Reconnaissance groups upload, curate, and publish wind, seismic, and coastal damage data they gather during field reconnaissance missions, so these datasets are available shortly after a disaster. As a part of the education and community outreach efforts of DesignSafe, training materials and collaboration space are also offered to the disaster risk management community.

Multidisciplinary approach to COVID-19 risk communication: A framework and tool for individual and regional risk assessment

The COVID-19 pandemic has exceeded over ten million cases globallywith no vaccine available yet. Different approaches are followed to mitigate its impact and reduce its spreading in different countries, but limiting mobility and exposure have been de-facto precaution to reduce transmission. However, a full lockdown cannot be sustained for a prolonged period. Evidence-based, multidisciplinary approach on risk zoning, personal and transmission risk assessment on a near real-time, and risk communication would support the optimized decisions to minimize the impact of coronavirus on our lives. This paper presents a framework to assess the individual and regional risk of COVID-19 along with risk communication tools and mechanisms. Relative risk scores on a scale of 100 represent the integrated risk of influential factors. The personal risk model incorporates: age, exposure history, symptoms, local risk and existing health condition, whereas regional risk is computed through the actual cases of COVID-19, public health risk factors, socioeconomic condition of the region, and immigration statistics. A web application tool (www.covira.info) has been developed, where anyone can assess their risk and find the guided information links primarily for Nepal. This study provides regional risk for Nepal, but the framework is scalable across the world. However, personal risk can be assessed immediately from anywhere.