Wei-Ning Xiang

The Use of Scenarios in Land-Use Planning

Land-development scenarios as a means of representing the future have been in the planners toolkit for several decades. In this paper we provide a systematic view of four basic issues that concern scenarists and scenario users—the concepts, functions, credentials, and efficacy of land-development scenarios. Drawing upon the wealthy and expanding pool of knowledge and experience as reported in the literature, we put forward the notion that a land-development scenario set is both a bridge that connects the process of modeling with that of planning and a cognitive apparatus that stretches peoples thinking and broadens their views in planning. The dual function entitles a scenario set to be a favored member of a family of innate instruments that humans operate in making decisions. Under this overarching framework, we propose three credentials that are by no means exhaustive yet are claimed to be essential for a scenario set to perform best the dual function. These are plausible unexpectedness, informational vividness, and cognitively ergonomic design. After exploring the efficacy issue of a scenario set with respect to its impacts on communities at large, we suggest that basic research efforts be underway that aim at the development of unified theories of land-development scenarios, or even scenarios in general, under a possible name of scenariology—the study of scenarios.

Planning for multi-purpose greenways in Concord, North Carolina

Abstract Small towns across the southern Piedmont of North Carolina are experiencing rapid growth and encroachment from larger neighboring municipalities. Many of these communities are confronted with the tough issue of preserving the quality of the environment, while at the same time allowing development to occur. Greenways are an excellent mechanism that balances needs for both conservation and growth. Once considered to be just a vegetated linear area for preventative purposes, greenways have evolved into a resource that can meet the public’s needs for recreation, environmental protection, and alternative transportation. There has also been a shift of focus in greenway planning: from a single-objective paradigm of environmental protection or natural conservation to a multi-objective process that allocates greenways as a resource to satisfy the public’s demands for all three benefits. However, these exciting developments bring a serious challenge to greenway planners: how to delineate future greenway corridors so that all the many functions are properly incorporated and the potential benefits are maximized? In this paper we demonstrate, through a project for the City of Concord, North Carolina, that such a challenge can be met by using a systematic approach to greenway planning. With this approach, we identified future greenway corridors within the City of Concord that best serve the multiple objectives of environmental protection, recreation, and alternate transportation. These alternative greenway scenarios will later be used by the local communities, public officials, and planners as an information basis in their pursuit of a well-connected and balanced land development in the city. It is hoped that the results will be integrated into the city’s comprehensive land use plan.

Critical Infrastructure Integration Modeling and Simulation

The protection of critical infrastructures, such as electrical power grids, has become a primary concern of many nation states in recent years. Critical infrastructures involve multi-dimensional, highly complex collections of technologies, processes, and people, and as such, are vulnerable to potentially catastrophic failures on many levels. Moreover, cross-infrastructure dependencies can give rise to cascading and escalating failures across multiple infrastructures. In order to address the problem of critical infrastructure protection, our research is developing innovative approaches to modeling critical infrastructures, with emphasis on analyzing the ramifications of cross-infrastructure dependencies. This paper presents an initial overview of the research and of the modeling environment under development.

A GIS based method for trail alignment planning

Abstract Presented in this article is a new method for park trail alignment planning. With the assistance of a computerized geographic information system (GIS), it searches, through extensive survey and analysis of areas physical, ecological, and land use conditions, for a connecting path (i.e. trail alignment) that links a future trails origin and destination by land parcel cells of the greatest trail potential. Trail alignments that are delineated and selected by the model provide a basis for quality site design. Tested in a North Carolina state park, the method proves to be effective, efficient, and practical.

Learning the Critical Infrastructure Interdependencies through an Ontology-Based Information System:

A critical infrastructure (CI) is an array of assets and systems that, if disrupted, would threaten national security, economy, public health and safety, and way of life. Essential to the practice of critical infrastructure planning and drills are two pieces of knowledge. One concerns the interactions within a CI system (intradomain interdependencies), and the other concerns the interactions among the CI systems (cross-domain interdependencies). A thorough understanding of these two interwoven CI interdependencies is crucial to such tasks as vulnerability assessment, scenario composition, and homeland security drills. In this paper we present a new approach that facilitates the learning of the interdependencies. Employing a loosely coupled system of GIS and an ontology-based object modeling system developed in this study, it represents and visualizes the intradomain and cross-domain CI interdependencies both diagrammatically and geographically. The system and its knowledge representation methodology were tested through a case study in the Southeastern United States.

Meeting critical challenges and striving for urban sustainability in China

Abstract China has experienced outstanding economic growth during the last three decades through urbanization. But at the same time, many ecological and social issues have been marginalized, leading to problems in public safety, health, and social equity. Such a pattern of development is unlikely to be sustainable. In this article, we examine these issues and the challenges that come with resolving them, and advocate a holistic and pragmatic approach to the research and practice of urban sustainability in China.

Enabling System of Systems Analysis of Critical Infrastructure Behaviors

Critical infrastructures are highly complex collections of people, processes, technologies, and information; they are also highly interdependent where disruptions to one infrastructure commonly cascade in scope and escalate in impact across other infrastructures. While it is unlikely that disruptions can be prevented with certainty, an effective practice of critical infrastructure analysis can reduce their frequency and/or lessen their impact. We contend that proper critical infrastructure analysis necessitates a system of systems approach. In this paper, we identify requirements for integrated modeling and simulation of critical infrastructures. We also present our integrated modeling and simulation framework based on a service-oriented architecture that enables system of systems analysis of such infrastructures.

Surface Heat Island in Shanghai and Its Relationship with Urban Development from 1989 to 2013

The continuous expansion of impervious artificial surfaces in cities has significantly influenced the urban thermal environment. This paper examines the spatiotemporal variation of the diurnal surface urban heat island (SUHI) in Shanghai from 1989 to 2013, a period during which the city has experienced drastic development changes. A remote sensing approach was taken to derive the spatial patterns of Shanghai’s land surface temperature (LST) from Landsat Thematic Mapper (TM) images and Operational Land Imager (OLI) data. The LST pattern was further classified into five LST classes to look at the relative SUHI intensity level across the whole city. Spatial analyses, namely, spatial association and centroid movement analysis, were conducted to reveal the trends of LST changes at both local and holistic scales. To understand the potential drivers for the present spatiotemporal variation of SUHI, different indicators including land use change, population density, night light data, and vegetation were analyzed and compared with LST changes. Based on the quantitative analysis and the socioeconomic context of Shanghai, “heating up” regions were identified, possible reasons for such SUHI variation were summarized, and districts that are most vulnerable to extreme heat conditions were projected. In terms of implication for urban development, planning and design recommendations were suggested to improve the urban thermal environment in Shanghai.

Isolation and characterization of diesel degrading bacteria, Sphingomonas sp. and Acinetobacter junii from petroleum contaminated soil

Two indigenous bacteria of petroleum contaminated soil were characterized to utilize diesel fuel as the sole carbon and energy sources in this work. 16S rRNA gene sequence analysis identified these bacteria as Sphingomonas sp. and Acinetobacter junii. The ability to degrade diesel fuel has been demonstrated for the first time by these isolates. The results of IR analyses showed that Sphingomonas sp. VA1 and A. junii VA2 degraded up to 82.6% and 75.8% of applied diesel over 15 days, respectively. In addition, Sphingomonas sp. VA1 possessed the higher cellular hydrophobicities of 94% for diesel compared to 81% by A. junii VA2. The isolates Sphingomonas sp. VA1 and A. junii VA2 exhibited 24% and 18%, respectively emulsification activity. This study reports two new diesel degrading bacterial species, which can be effectively used for bioremediation of petroleum contaminated sites.

An Integrated Methodology For Critical Infrastructure Modeling And Simulation

Integral to effective critical infrastructure analysis is the assessment of infrastructure vulnerabilities, which provides insights into potential disruptions that can enhance protection plans and response and recovery operations. Effective critical infrastructures analysis, however, must account for the complex, multi-dimensional characteristics of infrastructures and the dependencies between infrastructures. This paper presents a new methodology for integrated modeling and simulation that supports such analysis. An integrated analysis environment that embodies this new methodology is presented as a proof of concept.