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911.
Pao‐Shan Yu Chia‐Jung Chen Shiann‐Jong Chen Shu‐Chen Lin 《Journal of the American Water Resources Association》2001,37(1):151-166
ABSTRACT: A reliable forecasting model is essential in real‐time flood forecasting for reducing natural damage. Efforts to develop a real‐time forecasting model over the past two decades have been numerous. This work applies the Grey model to forecast rainfall and runoff owing to the model's relative ability to predict the future using a small amount of historical data. Such a model significantly differs from the stochastic and deterministic models developed previously. Ten historical storm events from two catchment areas in northern Taiwan are selected to calibrate and verify the model. Results in this study demonstrate that the proposed models can reasonably forecast runoff one to four hours ahead, if the Grey error prediction method is further used to update the output of the model. 相似文献
912.
ABSTRACT: In the Green Mountain state of Vermont, droughts of one form or another and of varying intensities, seventies, and areal extent are not uncommon occurrences. The 1990s were marked by at least three drought events of which the 1998 to 1999 was the most recent. In spite of this recurrence, ongoing drought monitoring and mitigative planning efforts are not as advanced as they could be and no official drought plan exists for the state. This article is the first of two in this volume. It summarizes the cascade of drought types that impacted the state during the 1998 to 1999 episode. From a number of precipitation statistics and drought indices, fine spatial scales (county or better) were found to best capture the character of drought impacts, while the weekly time step is recommended as the temporal unit around which to base planning and monitoring efforts. The companion article outlines a possible framework for drought planning efforts and highlights key constituencies to be included in the process. 相似文献
913.
Wen‐Cheng Liu Ming‐Hsi Hsu Albert Y. Kuo Ming‐Hsu Li 《Journal of the American Water Resources Association》2001,37(5):1405-1416
ABSTRACT: A vertical (laterally integrated) two‐dimensional numerical model has been applied to study the hydrodynamic characteristics and salt water intrusion in the Tanshui River estuarine system. The cross‐sectional profiles measured in 1978 and 1994 are schematized for model simulations. Detailed model calibration and verification have been conducted with water surface elevations, tidal current, salinity distributions, and residual velocities measured. The overall performance of the model is in qualitative agreement with the available field data. The model was then used to study how hydrodynamics and salt water intrusion change in response to changes in bathymetry. The model simulations indicate that more tidal energy propagates into the estuarine system in 1994 because of the substantial increase in river cross‐sections. The limits of salt intrusion in 1994 extended farther inland than those in 1978. On the other hand, the extent of mangrove wetland in the lower estuary has increased over the past 20 years and is likely a result of the increased salinity in the estuary. 相似文献
914.
María del Mar Glvez‐Rodríguez Arturo Haro‐de‐Rosario María del Carmen Caba‐Prez 《Disasters》2019,43(3):509-533
This study, based on situational crisis communication theory and set in the context of the Syrian refugee crisis, seeks first to conduct a comparative analysis of the management of online citizen engagement by local governments and non‐governmental organisations (NGOs). Second, it aims to examine the relationship between certain factors pertaining to the types of responses submitted by citizens via the social media of the aforementioned actors. The sample is composed of several Spanish local governments and NGOs belonging to Red de Municipios de Acogida de Refugiados (Local Government Network for Refugee Allocation). The main findings are that NGOs' online engagement with citizens is more than that of local governments. Notably, NGOs are much more active on their Facebook pages than are local governments. The two actors converge, though, in terms of disseminating instructive information and paying less attention to ‘basic crisis response options’. Moreover, the factors ‘content type’, ‘reputation’, and ‘woman’ affect the type of response messages sent by citizens. 相似文献
915.
Zhi‐Jun Liu Donald E. Weller David L. Correll Thomas E. Jordan 《Journal of the American Water Resources Association》2000,36(6):1349-1365
ABSTRACT: We measured the base‐flow stream chemistry in all the major physiographic provinces of the Chesapeake Bay drainage basin. The spatial variation of stream chemistry was closely related to differences in geology and land cover among the sampled watersheds. Some stream chemistry variables were strongly affected by geological settings in the watersheds while others were more influenced by land cover. The effects of land cover differed among chemical constituents and regions. Concentrations of Ca2+, Mg2+, pH, total alkalinity, and conductivity were mainly functions of carbonate bedrock, especially in the Great Valley. Nitrate‐N and total dissolved N were closely related to cropland and increased as the percentage of cropland increased. The rate of increase varied from region to region with the highest in the Piedmont. Na+ and Cl? were mainly affected by the percentage of developed area in a watershed, especially in the Coastal Plain and Piedmont. We observed no significant effects of region or land cover on species of phosphorus because samples were collected under base flow conditions and only dissolved forms were measured. Dissolved silicate (DSi) was not related to any other water chemistry variables. DSi increased as developed area decreased and cropland increased in the Coastal Plain, but these patterns were reversed in the Piedmont. There was no consistent pattern in the spatial variation of land cover effects on the reduced forms of N, dissolved organic P, dissolved organic matter, and K+. 相似文献
916.
Ke‐Sheng Cheng Hui‐Chung Yeh Ching‐Yuan Liou 《Journal of the American Water Resources Association》2000,36(3):511-521
ABSTRACT: Predicting the likelihood of a drought markedly enhances the efficiency of reservoir operations. This study applies the kriging method and time series analysis to predict inflows to Shihmen Reservoir in northern Taiwan. A subsequent reservoir operation simulation is employed to determine the drought lead time (DLT), the time before the onset of a drought. A more efficient reservoir operational strategy can be established with the aid of DLT and the probability of successful drought prediction (P s). Simulation results of reservoir operation over a period of three decades demonstrate that, at one month DLT, the kriging approach achieves 0.86 of P s for moderate droughts and 0.94 of P s for severe droughts. The kriging approach generally outperformed the time series approach in terms of DLT, P s of drought prediction, and the number of correctly predicted drought events. 相似文献
917.
Importance of Baseline Specification in Evaluating Conservation Interventions and Achieving No Net Loss of Biodiversity 总被引:1,自引:0,他引:1
J. W. BULL A. GORDON E. A. LAW K. B. SUTTLE E. J. MILNER‐GULLAND 《Conservation biology》2014,28(3):799-809
There is an urgent need to improve the evaluation of conservation interventions. This requires specifying an objective and a frame of reference from which to measure performance. Reference frames can be baselines (i.e., known biodiversity at a fixed point in history) or counterfactuals (i.e., a scenario that would have occurred without the intervention). Biodiversity offsets are interventions with the objective of no net loss of biodiversity (NNL). We used biodiversity offsets to analyze the effects of the choice of reference frame on whether interventions met stated objectives. We developed 2 models to investigate the implications of setting different frames of reference in regions subject to various biodiversity trends and anthropogenic impacts. First, a general analytic model evaluated offsets against a range of baseline and counterfactual specifications. Second, a simulation model then replicated these results with a complex real world case study: native grassland offsets in Melbourne, Australia. Both models showed that achieving NNL depended upon the interaction between reference frame and background biodiversity trends. With a baseline, offsets were less likely to achieve NNL where biodiversity was decreasing than where biodiversity was stable or increasing. With a no‐development counterfactual, however, NNL was achievable only where biodiversity was declining. Otherwise, preventing development was better for biodiversity. Uncertainty about compliance was a stronger determinant of success than uncertainty in underlying biodiversity trends. When only development and offset locations were considered, offsets sometimes resulted in NNL, but not across an entire region. Choice of reference frame determined feasibility and effort required to attain objectives when designing and evaluating biodiversity offset schemes. We argue the choice is thus of fundamental importance for conservation policy. Our results shed light on situations in which biodiversity offsets may be an inappropriate policy instrument Importancia de la Especificación de Línea de Base en la Evaluación de Intervenciones de Conservación y la Obtención de Ninguna Pérdida Neta de la Biodiversidad 相似文献
918.
This paper develops an analytical framework to investigate the relationship between water and armed conflict, and applies it to the ‘Summer War’ of 2006 between Israel and Lebanon (Hezbollah). The framework broadens and deepens existing classifications by assessing the impact of acts of war as indiscriminate or targeted, and evaluating them in terms of international norms and law, in particular International Humanitarian Law (IHL). In the case at hand, the relationship is characterised by extensive damage in Lebanon to drinking water infrastructure and resources. This is seen as a clear violation of the letter and the spirit of IHL, while the partial destruction of more than 50 public water towers compromises water rights and national development goals. The absence of pre‐war environmental baselines makes it difficult to gauge the impact on water resources, suggesting a role for those with first‐hand knowledge of the hostilities to develop a more effective response before, during, and after armed conflict. 相似文献
919.
Pierre‐Nicolas Carron Philippe Reigner Laurent Vallotton Jean‐Gabriel Clouet Claude Danzeisen Mathias Zürcher Bertrand Yersin 《Disasters》2014,38(2):434-450
In case of a major incident or disaster, the advance medical rescue command needs to manage several essential tasks simultaneously. These include the rapid deployment of ambulance, police, fire and evacuation services, and their coordinated activity, as well as triage and emergency medical care on site. The structure of such a medical rescue command is crucial for the successful outcome of medical evacuation at major incidents. However, little data has been published on the nature and structure of the command itself. This study presents a flexible approach to command structure, with two command heads: one emergency physician and one experienced paramedic. This approach is especially suitable for Switzerland, whose federal system allows for different structures in each canton. This article examines the development of these structures and their efficiency, adaptability and limitations with respect to major incident response in the French‐speaking part of the country. 相似文献
920.
A field hospital overseas requires various types of communication equipment. This study presents the communications equipment used by three Israeli field hospital delegations to earthquake sites at Adapazari, Turkey, in 1999, Port‐au‐Prince, Haiti, in 2010 and Minamisanriku, Japan, in 2011. The delegations to Turkey and Haiti were relatively large (105–230 personnel) and were on the site early (three to four days after each event). The 55‐person delegation to Japan arrived later and was established as an outpatient community hospital. Standard military VHF radios were the only effective tool up to 5 km, until cellular coverage was regained (1–2 weeks after each event). International communication was good. While short‐wave communication (telephone and Internet) was used in Turkey, a direct satellite channel was set up in Haiti. In Japan, BGAN Inmarsat provided efficient Wi‐Fi for all needs. Motorola walkie talkies were not efficient beyond the immediate vicinity. This paper recommends continued use of military‐specification equipment alongside newer modalities, particularly in situations where infrastructure is damaged. 相似文献