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101.
Development and Operational Testing of a Super‐Ensemble Artificial Intelligence Flood‐Forecast Model for a Pacific Northwest River 下载免费PDF全文
Dominique R. Bourdin Dave Campbell Roland B. Stull Tobi Gardner 《Journal of the American Water Resources Association》2015,51(2):502-512
Coastal catchments in British Columbia, Canada, experience a complex mixture of rainfall‐ and snowmelt‐driven contributions to flood events. Few operational flood‐forecast models are available in the region. Here, we integrated a number of proven technologies in a novel way to produce a super‐ensemble forecast system for the Englishman River, a flood‐prone stream on Vancouver Island. This three‐day‐ahead modeling system utilizes up to 42 numerical weather prediction model outputs from the North American Ensemble Forecast System, combined with six artificial neural network‐based streamflow models representing various slightly different system conceptualizations, all of which were trained exclusively on historical high‐flow data. As such, the system combines relatively low model development times and costs with the generation of fully probabilistic forecasts reflecting uncertainty in the simulation of both atmospheric and terrestrial hydrologic dynamics. Results from operational testing by British Columbia's flood forecasting agency during the 2013‐2014 storm season suggest that the prediction system is operationally useful and robust. 相似文献
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We study the role of intertemporal preference representations in a model of economic growth, stock pollutant and endogenous risk of catastrophic collapse. We contrast two polar instances of risk-sensitive preferences: the traditional “discounted utility” model, which imposes a positive rate of pure time preference and risk neutrality with respect to intertemporal utility, and multiplicatively separable preferences, which display risk aversion in that dimension but no pure time preferences. We show that both representations of preferences can rationalize the same economy when there is no collapse risk associated with pollution. Once we introduce a collapse risk whose hazard rate depends on the pollution stock, multiplicatively separable preferences are associated with a much higher value of catastrophic risk reduction, and a more stringent policy response. A relatively high discount rate may thus be compatible with large emissions abatement in the face of a low probability large impact event, reflecting preferences for catastrophic risk reduction. 相似文献
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Since the United Nations Conference on Environment and Development (UNCED) [1992, Agenda 21: programme of action for sustainable development. United Nations Conference on Environment and Development (UNCED), 3-14 June 1992. Rio de Janeiro, Brazil, 294pp.], the management of information has become central to the management of forest resources. In the cases of North America and Europe, similar issues have been challenging policy makers as they determine the information suitable for monitoring progress towards sustainable forest management (SFM). Using an 'online' survey, this research explored multiple stakeholder perspectives on monitoring and information reporting for SFM in different jurisdictions. The research was based on the premise that an analysis of the variation in stakeholder observations across a range of SFM 'issue areas' could provide valuable insight into the perceived need for SFM-related monitoring and information reporting in the regions of Europe, Canada and the USA. Despite the traditional limitations associated with exploratory survey research, the results indicate a demand for more information on SFM-related issues. The results also highlight the degree to which the perceptions of a sample of stakeholders can differ between Europe, USA and Canada. While these results cannot be generalized beyond the present study, they do suggest that further studies are needed to understand stakeholder perspectives on forestry-related monitoring and information reporting in different jurisdictions. 相似文献
108.
An integrated fuzzy-stochastic modeling approach for risk assessment of groundwater contamination 总被引:7,自引:0,他引:7
An integrated fuzzy-stochastic risk assessment (IFSRA) approach was developed in this study to systematically quantify both probabilistic and fuzzy uncertainties associated with site conditions, environmental guidelines, and health impact criteria. The contaminant concentrations in groundwater predicted from a numerical model were associated with probabilistic uncertainties due to the randomness in modeling input parameters, while the consequences of contaminant concentrations violating relevant environmental quality guidelines and health evaluation criteria were linked with fuzzy uncertainties. The contaminant of interest in this study was xylene. The environmental quality guideline was divided into three different strictness categories: "loose", "medium" and "strict". The environmental-guideline-based risk (ER) and health risk (HR) due to xylene ingestion were systematically examined to obtain the general risk levels through a fuzzy rule base. The ER and HR risk levels were divided into five categories of "low", "low-to-medium", "medium", "medium-to-high" and "high", respectively. The general risk levels included six categories ranging from "low" to "very high". The fuzzy membership functions of the related fuzzy events and the fuzzy rule base were established based on a questionnaire survey. Thus the IFSRA integrated fuzzy logic, expert involvement, and stochastic simulation within a general framework. The robustness of the modeling processes was enhanced through the effective reflection of the two types of uncertainties as compared with the conventional risk assessment approaches. The developed IFSRA was applied to a petroleum-contaminated groundwater system in western Canada. Three scenarios with different environmental quality guidelines were analyzed, and reasonable results were obtained. The risk assessment approach developed in this study offers a unique tool for systematically quantifying various uncertainties in contaminated site management, and it also provides more realistic support for remediation-related decisions. 相似文献
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M. Shafiqul Islam Rehan Sadiq Manuel J. Rodriguez Homayoun Najjaran Alex Francisque Mina Hoorfar 《The Environmentalist》2014,34(1):168-179
The main purpose of a water distribution system (WDS) is to deliver safe water of desirable quality, quantity and continuity to consumers. However, in many cases, a WDS fails to fulfill its goal owing to structural and associated hydraulic failures and/or water quality failures. The impact of these failures can be reduced significantly if preventive actions are taken based on their potential of occurrences or if a failure occurs and is detected within a minimum period of time after its occurrence. The aim of this research was to develop a forensic system for WDS failures. As part of the proposed forensic analysis, a framework has been developed, which investigates structural and associated hydraulic failures as well as water quality failures and integrates all failure investigation under a single platform. Under this framework, four different models have been developed to evaluate and identify structural and associated hydraulic failures and water quality failures. If a failure is detected in the system, the framework is capable of identifying the most probable location of the failure. To investigate the effectiveness of the proposed framework, the developed models have been tested and implemented in different WDSs. 相似文献
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Kristin McIlhenney 《Local Environment》2014,19(6):605-625
This paper addresses claims that the value-added wood industries contribute towards an economically and environmentally sustainable forest economy in British Columbia, Canada. The small firms that comprise the value-added industries have grown in number, are relatively labour intensive, draw upon diverse, small volume timber supplies, and serve a wide variety of niche markets. Conceptually, the study is informed by an integration of the flexible specialisation model with green entrepreneurship. Empirically, the study adopts an extended case study approach and is based on in-depth semi-structured interviews with respondents of 41 small firms that represent various value-added wood processing activities in Metro Vancouver and with industry associations. The study found that these firms are modestly flexibly specialised and locally embedded but inter-firm networking is weak. As green entrepreneurs, they reveal variation in environmental awareness and performance but are adopters rather than leaders. 相似文献