Rae Zimmerman

Optimal Resource Allocation for Defense of Targets Based on Differing Measures of Attractiveness

This article describes the results of applying a rigorous computational model to the problem of the optimal defensive resource allocation among potential terrorist targets. In particular, our study explores how the optimal budget allocation depends on the cost effectiveness of security investments, the defenders valuations of the various targets, and the extent of the defenders uncertainty about the attackers target valuations. We use expected property damage, expected fatalities, and two metrics of critical infrastructure (airports and bridges) as our measures of target attractiveness. Our results show that the cost effectiveness of security investment has a large impact on the optimal budget allocation. Also, different measures of target attractiveness yield different optimal budget allocations, emphasizing the importance of developing more realistic terrorist objective functions for use in budget allocation decisions for homeland security.

A Survey of Approaches for Assessing and Managing the Risk of Extremes

In this paper, we review methods for assessing and managing the risk of extreme events, where “extreme events” are defined to be rare, severe, and outside the normal range of experience of the system in question. First, we discuss several systematic approaches for identifying possible extreme events. We then discuss some issues related to risk assessment of extreme events, including what type of output is needed (e.g., a single probability vs. a probability distribution), and alternatives to the probabilistic approach. Next, we present a number of probabilistic methods. These include: guidelines for eliciting informative probability distributions from experts; maximum entropy distributions; extreme value theory; other approaches for constructing prior distributions (such as reference or noninformative priors); the use of modeling and decomposition to estimate the probability (or distribution) of interest; and bounding methods. Finally, we briefly discuss several approaches for managing the risk of extreme events, and conclude with recommendations and directions for future research.

Social implications of infrastructure network interactions

resources and services for transportation, energy, communications, water supply, and wastewater collection and treatment. In large part, the increasing spread of population settlements at the periphery of cities and the increasing density and vertical integration of urban cores have increased reliance upon the connectivity that these networks provide. These infrastructure networks are, in turn, dependent upon one another, both functionally and spatially, in very complex ways, and that interdependence is increased as new capacity-enhancing infrastructure technologies are developed. The extent of these dependencies appears to be escalating, and that results in interactions among the systems and produces effects upon environments that are difficult to predict. Integrating these services can improve the performance of the infrastructures, lower investment costs, and improve urban lifestyles. However, although some spatial and functional coordination of these networks has occurred, the rapid growth in their deployment, advances in network technology, and changes in the distribution of the populations the networks serve, continue to create disruptions in the infrastructure systems. These disruptions occur, for example, in the

Decision-making and the vulnerability of interdependent critical infrastructure

Interdependencies among critical infrastructure systems are well recognized as key points of vulnerability that can compromise system performance especially during extreme events. At the heart of these vulnerabilities are decisions, often unnoticed and indirect, which occur anywhere from infrastructure planning, siting and design through operation and maintenance. The key contributions of the paper are (i) the presentation of a method for constructing a catalog of infrastructure interdependences, (ii) the construction of a set of indicators transferable to other databases, and (iii) preliminary analytical results of the application of the indicators to a sample database of catalogued events with inter dependencies. This paper addresses how case analysis findings can be used in decision making to promote non-adverse interdependency-related outcomes from extreme events. Critical infrastructure analyzed includes facilities and services for transportation, telecommunications, water supply, wastewater, electric power and other energy infrastructure. Event databases for this research include government, industry, academic and media reports

Information and farmers’ attitudes about pesticides, water quality, and related environmental effects

Abstract This paper investigates the effects of information from different sources on farmers’ attitudes regarding the effects of pesticides and other agricultural chemicals on environmental quality using a survey of 2700 farmers in three mid-Atlantic states. Farmers’ beliefs are similar to those of the general public on average, but are distributed more uniformly, suggesting that the farm community may be more polarized on environmental issues than the general public. Farmers regard first-hand sources of information such as direct field observation and pesticide labels as being the most important. Chemical dealers and extension rank next in importance. Farmers who attached greater importance to information from news media and extension expressed greater environmental concern. Farmers who found information from chemical dealers more important expressed greater concern about injury to wildlife and pesticides in drinking water but less concern about general environmental quality problems associated with agricultural chemicals.

Adverse Health Experiences, Environmental Attitudes, and Pesticide Usage Behavior of Farm Operators

Water pollution from agricultural pesticides continues to be a public concern. Given that the use of such pesticides on the farm is largely governed by voluntary behavior, it is important to understand what drives farmer behavior. Health belief models in public health and social psychology argue that persons who have adverse health experiences are likely to undertake preventive behavior. An analogous hypothesis set was tested here: farmers who believe they have had adverse health experiences from pesticides are likely to have heightened concerns about pesticides and are more likely to take greater precautions in dealing with pesticides. This work is based on an original survey of a population of 2700 corn and soybean growers in Maryland, New York, and Pennsylvania using the U.S. Department of Agriculture data base. It was designed as a mail survey with telephone follow-up, and resulted in a 60 percent response rate. Farm operators report experiencing adverse health problems they believe are associated with pesticides that is equivalent to an incidence rate that is higher than the reported incidence of occupational pesticide poisonings, but similar to the reported incidence of all pesticide poisonings. Farmers who report experiencing such problems have more heightened concerns about water pollution from fertilizers and pesticides, and illness and injury from mixing, loading, and applying pesticides than farmers who have not experienced such problems. Farmers who report experiencing such problems also are more likely to report using alternative pest management practices than farmers who do not report having such problems. This implies that farmers who have had such experiences do care about the effects of application and do engage in alternative means of pest management, which at least involve the reduction in pesticide use.

Causes, cost consequences, and risk implications of accidents in US hazardous liquid pipeline infrastructure

Abstract In this paper the causes and consequences of accidents in US hazardous liquid pipelines that result in the unplanned release of hazardous liquids are examined. Understanding how different causes of accidents are associated with consequence measures can provide important inputs into risk management for this (and other) critical infrastructure systems. Data on 1582 accidents related to hazardous liquid pipelines for the period 2002–2005 are analyzed. The data were obtained from the US Department of Transportation’s Office of Pipeline Safety (OPS). Of the 25 different causes of accidents included in the data the most common ones are equipment malfunction, corrosion, material and weld failures, and incorrect operation. This paper focuses on one type of consequence–various costs associated with these pipeline accidents–and causes associated with them. The following economic consequence measures related to accident cost are examined: the value of the product lost; public, private, and operator property damage; and cleanup, recovery, and other costs. Logistic regression modeling is used to determine what factors are associated with nonzero product loss cost, nonzero property damage cost and nonzero cleanup and recovery costs. The factors examined include the system part involved in the accident, location characteristics (offshore versus onshore location, occurrence in a high consequence area), and whether there was liquid ignition, an explosion, and/or a liquid spill. For the accidents associated with nonzero values for these consequence measures (weighted) least squares regression is used to understand the factors related to them, as well as how the different initiating causes of the accidents are associated with the consequence measures. The results of these models are then used to construct illustrative scenarios for hazardous liquid pipeline accidents. These scenarios suggest that the magnitude of consequence measures such as value of product lost, property damage and cleanup and recovery costs are highly dependent on accident cause and other accident characteristics. The regression models used to construct these scenarios constitute an analytical tool that industry decision-makers can use to estimate the possible consequences of accidents in these pipeline systems by cause (and other characteristics) and to allocate resources for maintenance and to reduce risk factors in these systems.

Chapter 4: infrastructure impacts and adaptation challenges.

Creating an overall climate change adaptation strategy for urban infrastructure poses considerable conceptual and operational challenges. An understanding of the characteristics of a city’s infrastructure that make it particularly vulnerable to the impacts of climate change is a critical foundation for understanding the severity of the impacts and the means for adaptation. Historical events that have compromised a city’s infrastructure under conditions similar to those associated with climate change also provide information about what a city might expect in the way of consequences from a future of increased temperatures, precipitation, and sea level rise. This chapter explores the challenges to climate change adaptation in major urban infrastructure sectors with a focus on New York City, draws lessons from adaptation efforts under way in other large metropolitan regions, and discusses the role of the private sector in urban adaptation.

Mass Transit Infrastructure and Urban Health

Mass transit is a critical infrastructure of urban environments worldwide. The public uses it extensively, with roughly 9 billion mass transit trips occurring annually in the United States alone according to the U.S. Department of Transportation data. Its benefits per traveler include lower emissions of air pollutants and energy usage and high speeds and safety records relative to many other common modes of transportation that contribute to human health and safety. However, mass transit is vulnerable to intrusions that compromise its use and the realization of the important benefits it brings. These intrusions pertain to physical conditions, security, external evironmental conditions, and equity. The state of the physical condition of transit facilities overall has been summarized in the low ratings the American Society of Civil Engineers gives to mass transit, and the large dollar estimates to maintain existing conditions as well as to bring on new improvements, which are, however, many times lower than investments estimated for roadways. Security has become a growing issue, and numerous incidents point to the potential for threats to security in the US. External environmental conditions, such as unexpected inundations of water and electric power outages also make transit vulnerable. Equity issues pose constraints on the use of transit by those who cannot access it. Transit has shown a remarkable ability to rebound after crises, most notably after the September 11, 2001 attacks on the World Trade Center, due to a combination of design and operational features of the system. These experiences provide important lessons that must be captured to provide proactive approaches to managing and reducing the consequences of external factors that impinge negatively on transit.

Analyzing cascading effects within infrastructure sectors for consequence reduction

Cascading effects of infrastructure failures from terrorist attacks or natural hazards can greatly increase the magnitude of impacts from a failure of any given infrastructure. Interdependencies among infrastructure sectors in part drive these effects. Capturing how interdependencies operate and heighten impacts to develop procedures and policies to improve recovery is less well understood. This paper first presents an accounting system to identify where interdependencies are likely to occur. Second, given interdependencies, ways to portray vulnerabilities from interdependencies and estimate magnitude with qualitative or integer scales are presented from prior research and event databases. The methodology to quantify interdependencies and associated cascades builds on work on electric power outages and impacts they had on other infrastructure, such as oil and natural gas, electricity, transportation, and water. The method can be used to analyze connections between restoration times and types of interconnections failed and alternative technologies to reduce impacts of cascades.