Modeling structural change in spatial system dynamics: A Daisyworld example

System dynamics (SD) is an effective approach for helping reveal the temporal behavior of complex systems. Although there have been recent developments in expanding SD to include systems' spatial dependencies, most applications have been restricted to the simulation of diffusion processes; this is especially true for models on structural change (e.g. LULC modeling). To address this shortcoming, a Python program is proposed to tightly couple SD software to a Geographic Information System (GIS). The approach provides the required capacities for handling bidirectional and synchronized interactions of operations between SD and GIS. In order to illustrate the concept and the techniques proposed for simulating structural changes, a fictitious environment called Daisyworld has been recreated in a spatial system dynamics (SSD) environment. The comparison of spatial and non-spatial simulations emphasizes the importance of considering spatio-temporal feedbacks. Finally, practical applications of structural change models in agriculture and disaster management are proposed

A Methodology for Assessing Dynamic Resilience of Coastal Cities to Climate Change Influenced Hydrometeorological Disasters

Confronted with rapid urbanization, intensified tourism, population densification, increased migration, and climate change impacts, coastal cities are facing more challenges now than ever before. Traditional disaster management approaches are no longer sufficient to address the increased pressures facing urban areas. A paradigm shift from disaster risk reduction to disaster resilience building strategies is required to provide holistic, integrated, and sustainable disaster management looking forward. To address some of the shortcomings in current disaster resilience assessment research, a mathematical and computational framework was developed to help quantify, compare, and visualize dynamic disaster resilience. The proposed methodological framework for disaster resilience combines physical, economic, engineering, health, and social spatio-temporal impacts and capacities of urban systems in order to provide a more holistic representation of disaster resilience. To capture the dynamic spatio-temporal characteristics of resilience and gauge the effectiveness of potential climate change adaptation options, a disaster resilience simulator tool (DRST) was developed to employ the mathematical framework. The DRST is applied to a case study in Metro Vancouver, British Columbia, Canada. The simulation model focuses on the impacts of climate change-influenced riverine flooding and sea level rise for three future climates based on the results of the CGCM3 global climate model and two (2) future emissions scenarios. The output of the analyses includes a dynamic set of resilience maps and graphs to demonstrate changes in disaster resilience in both space and time. The DRST demonstrates the value of a quantitative resilience assessment approach to disaster management. Simulation results suggest that various adaptation options such as access to emergency funding, provision of mobile hospital services, and managed retreat can all help to increase disaster resilience. Results also suggest that, at a regional scale, Metro Vancouver is relatively resilient to climate change influenced-hydrometeorological hazards, however it is not distributed proportionately across the region. Although a pioneering effort by nature, the methodological and computational framework behind the DRST could ultimately provide decision support to disaster management professionals, policy makers, and urban planners

A Methodology for Municipal Flood Risk Assessment due to Climate Change: A City of London Case Study

ABSTRACT Flooding has devastating physical, social, economic and environmental consequences. It is important to identify and understand the evolution of these risks as climate changes. Most municipal infrastructure is designed using historical data which may no longer accurately represent current climate conditions. As a result, municipalities may be at greater risk of flood damage. The purpose of this study is to develop and test a municipal-level risk assessment methodology considering climate change-caused impacts of flooding. Floodplain maps derived from climate, hydrologic and hydraulic analyses provide direct input into risk assessment procedure. Inundated infrastructure and high risk areas are identified in tables and maps for each climate scenario using quantitative and qualitative risk calculations. The developed risk assessment methodology is applied as a case study to the City of London, Ontario, Canada. Results provide support for climate change adaptation policy development, decision making and emergency management

Updated Rainfall Intensity Duration Frequency Curves for the City of London under the Changing Climate

The main focus of this study is the update of rainfall IDF curves for the City of London under the conditions of changed climate. Predicted future climate change impacts for Southwestern Ontario include higher temperatures and increases in precipitation, leading to an intensification of the hydrologic cycle. One of the expected consequences of change is an increase in the magnitude and frequency of extreme events (e.g. high intensity rainfall, flash flooding, severe droughts, etc.). Changes in extreme events are of particular importance for the design, operation and maintenance of municipal water management infrastructure. Management of municipal water infrastructure (sewers, storm water management ponds or detention basins, street curbs and gutters, catchbasins, swales, etc) is based on the use of local rainfall Intensity Duration Frequency (IDF) curves developed using historical rainfall time series data. Annual extreme rainfall is fitted to a theoretical probability distribution from which rainfall intensities, corresponding to particular durations, are obtained. In the use of this procedure an assumption is made that historic hydro meteorological conditions can be used to characterize the future (i.e., the historic record is assumed to be stationary). This assumption is not valid under changing climatic conditions. Potential shifts in extreme rainfall at the local level demand revisions of the existing water infrastructure management regulations as well as changes in design practices. The objective of this report is to assess the change in IDF curves for use by the City of London under changing climatic conditions. This assessment is completed using (a) only data collected at the London Airport (b) for the period 1961 - 2002. This is all the information that is available from the Environment Canada (EC). An original methodology is developed in this study to update the rainfall intensity duration frequency (IDF) curves under changing climatic conditions. A non-parametric K-Nearest Neighbour weather generator algorithm operating on a daily time step is used to synthetically create long time series of weather data. The weather generator algorithm is developed to employ data collected by the Environment Canada for use in IDF analysis, including eight for-the-day-maximums of 5, 10, 15, 30 minutes, 1, 2, 6 and 12 hour, along with daily rainfall time series. The weather generator uses (a) a sophisticated shuffling mechanisms to produce synthetic data similar to the observed record; and (b) a perturbation mechanism that pushes the simulated data outside of their historic bounds, thereby generating sequences of extreme rainfall that are likely, but not yet been observed. Two climate scenarios are used in the analysis: (i) historic climate change scenario (that reshuffles and perturbs the observed data), and (ii) wet scenario (that modifies the observed record according to Global Circulation Model simulation outputs and then uses this data as the weather generator input). Results of the study include tabular and graphical presentation of updated IDF curves for the London Airport. Results are generated for return periods of 2, 5, 10, 25, 50, 100 and 250 years. The study presents the results of three simulations that differ in the historic input data. The first simulation analysis is based on the original London Airport data set for the period 1961 – 2001 obtained from the EC (eight for-the-day-maximums of 5, 10, 15, 30 minutes, 1, 2, 6 and 12 hour, and daily rainfall time series). Due to limitations of the original data set in correctly representing daily rainfall, the second simulation analysis is based on the combination of the original for-the-day-maximums for the period 1961 – 2002 (eight for-the-day-maximums of 5, 10, 15, 30 minutes, 1, 2, 6 and 12 hour) with hourly data collected at London Airport. Since the hourly data set also had some deficiencies, the third simulation analysis is performed that used the same combination of input data as the second analysis with modifications added to the last three years of observations. It is recommended that the modified data set be used for drawing conclusions of the study. The simulation results indicate that rainfall magnitude will increase under climate change for all durations and return periods. The outputs of the study indicate that: (i) the rainfall magnitude will be different in the future, (ii) the wet climate scenario reveals significant increase in rainfall intensity for a range of durations and return periods, and (iii) the increase in rainfall intensity and magnitude may have major implications on ways in which current (and future) municipal water management infrastructure is designed, operated, and maintained. Our recommendation is that the current IDF curves should be revised to reflect the potential impact of climate change. Results of comparison between the updated IDF curves for modified data set indicate small difference between the historic and wet climate change scenarios. This difference ranges between 0.1% and 12.2% with average value of approximately 4.5%. Therefore the recommendation is to proceed with potential revisions of the standards using the historic climate change scenario. Comparison between the updated IDF curves for modified data set (historic climate change scenario) and the EC IDF curves shows a difference that ranges between 10.7 % and 34.9% with average value of approximately 21%. Based on this comparison our recommendation to the City of London is to proceed with change of IDF curves in the range of 20%. Detailed economic analyses should be performed to justify the necessary investment that this change will require.https://ir.lib.uwo.ca/wrrr/1027/thumbnail.jp

City of London: Vulnerability of Infrastructure to Climate Change Final Report

The Earth\u27s climate is changing and these changes are documented to have a serious impact on municipal infrastructure. Current infrastructure is designed and constructed based on standards and codes developed decades ago. These standards and codes include historic climate and design storms which are no longer representative of the current climate. With the changes in climate patterns, infrastructure may no longer have the capacity to handle new climate loads. Thus, a region must adapt its policies and procedures to consider climate change and mitigate risks to municipal infrastructure. Climate modeling suggests that the City of London can expect to experience more frequent severe precipitation events in the future as a consequence of climate change. Flooding is therefore a natural hazard event of significance to this region and as such the City commissioned this study to assess the vulnerability of London’s public infrastructure to changing climate conditions. From a hazards perspective, vulnerability assessments provide insights into responses necessary to prevent loss of life, damages, or in worst cases disasters. From a climate change perspective, capturing the differential elements of vulnerability is a prerequisite for developing adaptation policies that will promote equitable and sustainable development. Risk is defined in this study as the intersection of a hazard (flooding) with vulnerability. The risk measure enables conclusions and recommendations to be made regarding the reliability of the infrastructure network within the city to adapt to the changing climate conditions. The study results are meant to identify and prioritize areas of high risk or interest within the city which are recommended for further investigation. These recommendations are meant to aid in policy development as it relates to municipal infrastructure and the future.https://ir.lib.uwo.ca/wrrr/1036/thumbnail.jp

Physical, Economical, Infrastructural and Social Flood Risk -- Vulnerability Analyses in GIS

An exhaustive knowledge of flood risk, vulnerability and exposure in different spatial locations is essential for developing an effective flood mitigation strategy for a watershed. In the present study, a flood risk-vulnerability analysis is performed. All four components of flood vulnerability: (a) physical; (b) economic; (c) infrastructure and (d) social, are evaluated individually using a Geographic Information System (GIS) environment. The proposed methodology estimates the impact on infrastructure vulnerability due to inundation of critical facilities, emergency service stations, and road bridges. The components of vulnerability are combined to determine the overall vulnerability. The patterns of land use and soil type are considered as two major components of flood exposure. Flood hazard maps, overall vulnerability and exposure are used to finally compute the flood risk at different locations in the watershed. The proposed methodology is implemented to six major damage centers in the Upper Thames River watershed, located in south-western Ontario of Canada to assess the flood risk. A web-based information system is developed for systematic presentation of the flood risk, vulnerability and exposures by postal code regions or Forward Sortation Areas (FSAs). The system is designed to provide support for different users, i.e., general public, decision-makers and water management professionals. An interactive analysis tool is developed within the web-based information system to assist in evaluation of the flood risk in response to a change in land use pattern.https://ir.lib.uwo.ca/wrrr/1019/thumbnail.jp

Developmental Stages and Work Capacities of Community Coalitions: How Extension Educators Address and Evaluate Changing Coalition Needs

Extension educators provide resources to community coalitions. The study reported here adds to what is known about community coalitions and applies an assessment framework to a state-level coalition-based Extension program on healthy relationships and marriages. The study combines the Internal Coalition Outcome Hierarchy (ICOH) framework with four coalition capacity categories: general, internal, external, and prevention. The findings from two focus groups, one with formation coalition leaders and one with midlevel coalition leaders, are presented. Recommendations are made for designing educational, service, and evaluation interventions to meet the needs of community coalitions at specific developmental stages

Immune or genetic-mediated disruption of CASPR2 causes pain hypersensitivity due to enhanced primary afferent excitability

Human autoantibodies to contactin-associated protein-like 2 (CASPR2) are often associated with neuropathic pain, and CASPR2 mutations have been linked to autism spectrum disorders, in which sensory dysfunction is increasingly recognized. Human CASPR2 autoantibodies, when injected into mice, were peripherally restricted and resulted in mechanical pain-related hypersensitivity in the absence of neural injury. We therefore investigated the mechanism by which CASPR2 modulates nociceptive function. Mice lacking CASPR2 (Cntnap2 ) demonstrated enhanced pain-related hypersensitivity to noxious mechanical stimuli, heat, and algogens. Both primary afferent excitability and subsequent nociceptive transmission within the dorsal horn were increased in Cntnap2 mice. Either immune or genetic-mediated ablation of CASPR2 enhanced the excitability of DRG neurons in a cell-autonomous fashion through regulation of Kv1 channel expression at the soma membrane. This is the first example of passive transfer of an autoimmune peripheral neuropathic pain disorder and demonstrates that CASPR2 has a key role in regulating cell-intrinsic dorsal root ganglion (DRG) neuron excitability

Lack of SARS Transmission among Healthcare Workers, United States

Healthcare workers accounted for a large proportion of persons with severe acute respiratory syndrome (SARS) during the worldwide epidemic of early 2003. We conducted an investigation of healthcare workers exposed to laboratory-confirmed SARS patients in the United States to evaluate infection-control practices and possible SARS-associated coronavirus (SARS-CoV) transmission. We identified 110 healthcare workers with exposure within droplet range (i.e., 3 feet) to six SARS-CoV–positive patients. Forty-five healthcare workers had exposure without any mask use, 72 had exposure without eye protection, and 40 reported direct skin-to-skin contact. Potential droplet- and aerosol-generating procedures were infrequent: 5% of healthcare workers manipulated a patient’s airway, and 4% administered aerosolized medication. Despite numerous unprotected exposures, there was no serologic evidence of healthcare-related SARS-CoV transmission. Lack of transmission in the United States may be related to the relative absence of high-risk procedures or patients, factors that may place healthcare workers at higher risk for infection

SARS-associated Coronavirus Transmission, United States

To better assess the risk for transmission of the severe acute respiratory syndrome–associated coronavirus (SARS-CoV), we obtained serial specimens and clinical and exposure data from seven confirmed U.S. SARS patients and their 10 household contacts. SARS-CoV was detected in a day-14 sputum specimen from one case-patient and in five stool specimens from two case-patients. In one case-patient, SARS-CoV persisted in stool for at least 26 days after symptom onset. The highest amounts of virus were in the day-14 sputum sample and a day-14 stool sample. Residual respiratory symptoms were still present in recovered SARS case-patients 2 months after illness onset. Possible transmission of SARS-CoV occurred in one household contact, but this person had also traveled to a SARS-affected area. The data suggest that SARS-CoV is not always transmitted efficiently. Laboratory diagnosis of SARS-CoV infection is difficult; thus, sputum and stool specimens should be included in the diagnostic work-up for SARS-CoV infection