2011 Vol. 2, No. 3

Display Method:
A Cover Technique to Verify the Reliability of a Model for Calculating Fuzzy Probabilities
Chongfu Huang
2011, 2(3): 1-10. doi: 10.1007/s13753-011-0011-x
Many models have been suggested to calculate fuzzy probabilities in risk analysis. In general, the reliability of a model is demonstrated by practical effects or proved theoretically. In this article we suggest a new approach called the cover technique to verify the model's reliability. The technique is based on a hypothesis that a statistical result can approximately confirm a fuzzy probability as a fuzzy-set-valued probability. A cover is constructed by many biprobability distributions. The consistency degree of a cover and a fuzzy probability distribution is employed to verify the reliability of a model. We present a case that shows how to construct a distribution-cover and calculate the consistency degree of the cover and a possibility-probability distribution. A series of numerical experiments with random samples from a normal distribution verify the reliability of the interior-outer-set model.
Understanding Risk Governance: Introducing Sociological Neoinstitutionalism and Foucauldian Governmentality for Further Theorizing
Wee-Kiat Lim
2011, 2(3): 11-20. doi: 10.1007/s13753-011-0012-9
This article traces the career of risk across prominent theoretical approaches by highlighting their key assumptions and premises, specifically the technical approach found in the physical sciences, and economics, psychology, and sociology in the social sciences. In each discipline, the strengths and limitations of each theoretical approach are pointed out. The discussion focuses on sociology in particular because other approaches-in treating risks as dominantly technical, psychological, or economic phenomena-tend to downplay the broader historical and socio-political context that impinges on risk construction and production, and its differential impact across society. This exploration points out that institutions play an important role in creating, managing, and distributing risks in society. After highlighting the integrated risk governance framework as a nascent practice-oriented framework, the framework is examined theoretically using sociological neoinstitutionalism and Foucault's concept of governmentality. The conclusion elaborates the challenges of using these two bodies of knowledge to study risk governance of extreme events. Although Foucault's concept of governmentality corrects neoinstitutional theory's ambivalence toward power, more work needs to be done in order to reconcile their divergent intellectual commitments.
Dilemmas and Pathways to Dealing with Flood Problems in Twenty-First Century China
Guoyi Han, Roger E. Kasperson
2011, 2(3): 21-30. doi: 10.1007/s13753-011-0013-8
With more than 60 percent of China's 1.34 billion population, about 50 percent of its most productive arable land, and the world's second largest and rapidly growing national GDP exposed to flooding of various kinds, China has an intractable flood problem. Envisioning potential impacts of climate change and continued intensification of floodplain development driven by rapid industrialization and urbanization, it is very likely that China will see a continued increase of exposure to floods this century. This overview article outlines and discusses fundamental dilemmas, plausible pathways, and key options for managing future flood risks in China in the context of rapid socioeconomic transition and climate change. Fundamental dilemmas are the embedded difficult trade-off choices, from balancing economic development with flood vulnerability reduction, to coordination and cooperation among increasingly diverse actors and across scales. Among plausible pathways, this article argues that a resilience strategy for managing flood risk is desirable. It would require human adjustment to flood, not by aiming for full protection and control but by adjusting our use of floodplains, integrating and experimenting with a wide range of flood risk management options, so that a dynamic balance is maintained between exposure and coping capacity and flood risk is contained at an acceptable level. Embracing variability and uncertainty lies at the heart of such a flood resilience centered paradigm. Reducing the flood toll cannot be had without trade-offs in economic development, food production, and agricultural productivity.
A Distributed Model for Real-Time Flood Forecasting in the Godavari Basin Using Space Inputs
Korada Hari Venkata Durga Rao, Vala Venkateshwar Rao, Vinay Kumar Dadhwal, Gandarbha Behera, Jaswant Raj Sharma
2011, 2(3): 31-40. doi: 10.1007/s13753-011-0014-7
Hydrological modelling of large river catchments has become a challenging task for water resources engineers due to its complexity in collecting and handling of both spatial and non-spatial data such as rainfall, gauge-discharge data, and topographic and hydraulic parameters. In this article, a flood forecast model is developed for the Godavari Basin, India through a distributed modelling approach using space inputs. The approach includes rainfall runoff modelling, hydrodynamic flow routing, calibration, and validation of the model with field discharge data. The study basin is divided into 128 subbasins to improve the model accuracy. Topographic and hydraulic parameters of each subbasin and channel are computed using the land use/land cover grid that is derived from the Indian Remote Sensing Satellite (IRS-P6) AWiFS sensor data (56 m resolution), Shuttled Radar Topographic Mission (SRTM) Digital Elevation Model (DEM), and the soil textural grid. The model is calibrated using the field hydrometeorological data of 2000 and validated with the data of 2001. The model was tested during the 2010 floods with real-time 3-hour interval hydrometeorological and daily evapotranspiration data. Accuracy in estimating the peak flood discharge and lag time was found to be very good. Flood forecast lead time is increased by 12 hours compared to conventional methods of forecasting.