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

Assessment of the Impact of Climate Variability and Change on the Reliability, Resiliency and Vulnerability of Complex Flood Protection Systems

An original modeling framework (DYHAM) for assessment of climate variation and change impacts on the performance of complex flood protection system has been developed and tested using the Red River basin (Manitoba) as a case study. Modeling framework allows for evaluation of different climate change scenarios generated by the global climate models. Temperature and precipitation are used as the main factors affecting flood flow generation. System dynamics modeling approach proved to be of great value in the development of system performance assessment model.The most important impact of climate variability and change on hydrologic processes is reflected in the change of flood patterns: flood starting time, peak value and timing. Floods in the Red River basin generally occur in spring when the increase in temperature initiates snowmelt that usually coincides with heavy rain. In this study more than 90% of floods (at Shellmouth reservoir on the Assiniboine River and at Ste. Agathe on the Red River) generated using three different climate models started earlier in March and April. We conclude that the increase in temperature from climate variation and change results in an earlier flood starting time in the Red River basin. The DYHAM assessment of the performance of Red River flood protection system is based on the flood flows, the capacity of flood control structures and failure flow levels at different locations in the basin. In the Assiniboine River basin, higher reliabilities at downstream locations are obtained indicating that Shellmouth reservoir plays an important role in reducing downstream flooding. However, a different trend was identified in the Red River basin. The study results show that flood protection capacity of the Red River infrastructure is sufficient under low reliability criteria but may not be sufficient under high reliability criteria.https://ir.lib.uwo.ca/wrrr/1000/thumbnail.jp

Fighting Floods Requires Better Long Term Planning

It is time for a new approach in flood emergency management. Rather than focusing on just the crises, planners need to look at the issue of vulnerability and its management.York's Knowledge Mobilization Unit provides services and funding for faculty, graduate students, and community organizations seeking to maximize the impact of academic research and expertise on public policy, social programming, and professional practice. It is supported by SSHRC and CIHR grants, and by the Office of the Vice-President Research & Innovation. [email protected] www.researchimpact.c

Role of Remote Sensing in Disaster Management

The objective of this report is to review the existing satellites monitoring Earth’s resources and natural disasters. Each satellite has different repeat pass frequency and spatial resolution (unless it belongs to the same series of satellites for the purpose of continuation of data flow with same specifications). Similarly, different satellites have different types of sensors on-board, such as, panchromatic, multispectral, infrared and thermal. All these sensors have applications in disaster mitigation, though depending on the electromagnetic characteristics of the objects on Earth and the nature of disaster itself. With a review of the satellites in orbit and their sensors the present work provides an insight to suitability of satellites and sensors to different natural disasters. For example, thermal sensors capture fire hazards, infrared sensors are more suitable for floods and microwave sensors can record soil moisture. Several kinds of disasters, such as, earthquake, volcano, tsunami, forest fire, hurricane and floods are considered for the purpose of disaster mitigation studies in this report. However, flood phenomenon has been emphasized upon in this study with more detailed account of remote sensing and GIS (Geographic Information Systems) applicability. Examples of flood forecasting and flood mapping presented in this report illustrate the capability of remote sensing and GIS technology in delineating flood risk areas and assessing the damages after the flood recedes. With the help of a case study of the Upper Thames River watershed the use of remote sensing and GIS has been illustrated for better understanding. The case study enables the professionals and planning authorities to realize the impact of urbanization on river flows. As the urban sprawl increases with the increase of population, the rainfall and snow melt reaches the river channels at a faster rate with higher intensity. In other words it can be inferred that through careful land use planning flood disasters can be mitigated.https://ir.lib.uwo.ca/wrrr/1002/thumbnail.jp

A Spatial Fuzzy Compromise Approach for Flood Disaster Management

Natural disasters affect regions with different intensity and produce damages that vary in space. Topographical features of the region; location of properties that may be exposed to the peril; level of exposure; impact of different mitigation measures; are all variables with considerable spatial variability. A new method for evaluation of disaster impacts has been presented in this report that takes into consideration spatial variability of variables involved and associated uncertainty. Flood management has been used to illustrate the utility of proposed approach. Floodplain management is a spatial problem. Representation of flood damage mitigation alternatives and objectives in space provides a better insight into the management problem and its characteristics. Protection of a region from floods can be achieved through various structural and non-structural measures. Comparison of different measures and evaluation of their impacts is based on the multiple criteria. If they are described spatially, decision-making problem can be conceptualized as spatial multi criteria decision-making (MCDM). Tkach and Simonovic (1997) introduced spatial Compromise Programming (SPC) technique to account for spatial variability in flood management. Some of the criteria and preferences of the stakeholders involved with flood management are subject to uncertainty that may originate in the data, knowledge of the domain or our ability to adequately describe the decision problem. The main characteristic of flood management is the existence of objective and subjective uncertainty. Fuzzy set theory has been successfully used to address both, objective and subjective uncertainty. Bender and Simonovic (2000) incorporated vagueness and imprecision as sources of uncertainty into multi criteria decision-making in water resources. In this report a new technique named Spatial Fuzzy Compromise Programming (SFCP) has been developed to enhance our ability to address the issues related to uncertainties in spatial environment. A general fuzzy compromise programming technique, when made 2 spatially distributed, proved to be a powerful and flexible addition to the list of techniques available for decision making where multiple criteria are used to judge multiple alternatives. All uncertain variables (subjective and objective) are modeled by way of fuzzy sets. In the present study, fuzzy measures have been introduced to spatial multi criteria decision-making in the GIS environment in order to account for uncertainties. Through a case study of the Red River floodplain near the City of St. Adolphe in Manitoba, Canada, it has been illustrated that the new technique provides measurable improvement in flood management. Final results in the form of maps that shown spatial distribution of the impacts of mitigation measures on the region can be of great value to insurance industry.https://ir.lib.uwo.ca/wrrr/1004/thumbnail.jp

Inverse Drought Risk Modelling of the Upper Thames River Basin

This report aims to present an alternate approach to climate change impact mod- elling of water resources. The focus of the project is on the analysis of existing water resources management guidelines specifically targeting critical hydrologic events (ex- treme droughts in this case). The critical hydrologic events are converted to their corresponding meteorologic conditions via use of an appropriate hydrologic model (continuous based hydrologic model for drought analysis). The local climatic signal is generated by use of a non-parametric weather generator linked to outputs from a global circulation model for three climate scenarios, and their corresponding fre- quency curves generated. Then, a critical hydrologic event of interest is selected, its corresponding meteorological condition obtained, and its frequency of occurrence for each climate scenario determined. It is noted that all climate change scenarios showed less frequent occurrence of extreme droughts. However, potentially severe droughts are still possible (with a chance of 1 in 10 any given year, sometime less) in the basin; this coupled with the fact that drought damage assessments are non existent in the basin suggests that new or improved drought management guidelines should be investigated. Based on the analysis presented, recommendations are made for future work to in- clude: (i) drought impact studies (where impacts to agriculture, recreation, wetlands, reservoir operation, ground water withdrawal and streamflow quality are assessed); (ii) definition of local drought triggers (including guidelines on subwatershed scale, as well as monitoring how drought triggers change over time); (iii) water quality man- agement (setting in place practises that enhance water quality over short and long term); (iv) education programs (to bring up to date knowledge in science to all who stand to be adversely impacted by drought).https://ir.lib.uwo.ca/wrrr/1015/thumbnail.jp

NDM-515: AN ORIGINAL MODEL OF INFRASTRUCTURE SYSTEM RESILIENCE

Infrastructure systems of transportation, water supply, telecommunications, power supply, etc. are not isolated but highly interconnected and mutually coupled. Infrastructure interdependences can increase system vulnerability and produce cascading failures at the regional or national scales. Taking the advantage of network theory structure analysis, this paper models street, water supply network, power grid and information infrastructure as network layers that are integrated into a multilayer network. The infrastructure interdependences are detailed using five basic dependence patterns of network fundamental elements. Definitions of dynamic cascading failures and recovery mechanisms of infrastructure systems are also established. The main focus of the paper is introduction of a new infrastructure network resilience measure capable of addressing infrastructure system as well as network component (layer) interdependences. The new measure is based on infrastructure network performance, proactive infrastructure network resistance capacity and reactive infrastructure network recovery capacity. With three resilience features and corresponding network properties develops paper, this the of dynamic space new quantitative measure -time resilience and a resilience simulation model resilience and network properties three dimensions of use for infrastructure network assessments. The resilience model is applicable to any type of infrastructure and its application can improve the infrastructure planning, design and maintenance decision making

Comparison of One-Dimensional and Two-Dimensional Hydrodynamic Modeling Approaches For Red River Basin

EXECUTIVE SUMMARY A devastating flood in Red River valley in 1997 emphasized the need to study the flood control measures in the Red River basin using state of the art modeling tools. The Red River and its floodplains can be modeled using one-dimensional, quasi two-dimensional or fully two-dimensional hydrodynamic models. Each modeling approach has its own advantages and limitations. The main purpose of this report is a comparison between one-dimensional (or quasi two dimensional) and fully two-dimensional hydrodynamic modeling approaches for modeling floods in the Red River basin. A two-dimensional hydrodynamic model, MIKE 21, coupled with Geographic Information System (GIS) has been used in this study to capture the hydraulic response of the Red River and its floodplains in extreme flooding conditions. The focus area for modeling is a section of the Red River basin from south of Winnipeg floodway to the town of Ste. Agathe in Manitoba, Canada. For comparison purposes, results produced by Klohn-Crippen (1999), using one-dimensional unsteady flow model, MIKE 11, have been used. MIKE 21, two-dimensional unsteady-flow model, is based on the finite-difference solution scheme and uses rectangular grids to resolve bathymetry. Simulations are made, using MIKE 21, to study the impact on flooding by modifying the operation of floodway. Problems associated with the application of a 2-D model are discussed especially with respect to the representation of terrain. Based on comparison of results, produced in this study using two-dimensional model MIKE 21 and reported by Klohn-Crippen (1999) using one-dimensional model MIKE 11, it is recommended that: The whole Red River basin should be modeled using a combination of quasi two dimensional and fully two-dimensional models. Fully two-dimensional model should be used only for areas of interest where detailed description of flow field is required, for example in the vicinity of major structures, communities and sensitive areas with high flood damage potential. Using combined modeling approach boundary conditions for two-dimensional model can be derived from results produced by one-dimensional model