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61.
62.
Anantharaman Chandrasekar C. Russell Philbrick Bruce Doddridge Richard Clark Panos G. Georgopoulos 《Environmental Fluid Mechanics》2005,4(4):339-365
This study presents a comparative evaluation of the prognostic meteorological Fifth Generation NCAR Pennsylvania State University Mesoscale Model (MM5) using data from the Northeast Oxidant and Particle Study (NE-OPS) research program collected over Philadelphia, PA during a summer episode in 1999. A set of model simulations utilizing a nested grid of 36 km, 12 km and 4 km horizontal resolutions with 21 layers in the vertical direction was performed for a period of 101 h from July 15, 1999; 12 UTC to July 19, 1999; 17 UTC. The model predictions obtained with 4 km horizontal grid resolution were compared with the NE-OPS observations. Comparisons of model temperature with aircraft data revealed that the model exhibited slight underestimation as noted by previous investigators. Comparisons of model temperature with aircraft and tethered balloon data indicate that the mean absolute error varied up to 1.5 °C. The comparisons of model relative humidity with aircraft and tethered balloon indicate that the mean relative error varied from –11% to –22% for the tethered balloon and from –5% to –30% for the aircraft data. The mean relative error for water vapor mixing ratio with respect to the lidar data exhibited a negative bias consistent with the humidity bias corresponding to aircraft and tethered balloon data. The tendency of MM5 to produce estimates of very low wind speeds, especially in the early-mid afternoon hours, as noted by earlier investigators, is seen in this study also. It is indeed true that the initial fields as well as the fields utilized in the data assimilation also contribute to some of the differences between the model and observations. Studies such as these which compare the grid averaged mean state variables with observations have inherent difficulties. Despite the above limitations, the results of the present study broadly conform to the general traits of MM5 as noted by earlier investigators. 相似文献
63.
64.
Dana Rathfon Rachel Davidson John Bevington Alessandro Vicini Arleen Hill 《Disasters》2013,37(2):333-355
Quantitative assessment of post‐disaster housing recovery is critical to enhancing understanding of the process and improving the decisions that shape it. Nevertheless, few comprehensive empirical evaluations of post‐disaster housing recovery have been conducted, and no standard measurement methods exist. This paper presents a quantitative assessment of housing recovery in Punta Gorda, Florida, United States, following Hurricane Charley of August 2004, including an overview of the phases of housing recovery, progression of recovery over time, alternative trajectories of recovery, differential recovery, incorporation of mitigation, and effect on property sales. The assessment is grounded in a conceptual framework that considers the recovery of both people and place, and that emphasises recovery as a process, not as an endpoint. Several data sources are integrated into the assessment—including building permits, remotely sensed imagery, and property appraiser data—and their strengths and limitations are discussed with a view to developing a standardised method for measuring and monitoring housing recovery. 相似文献
65.
Random walks are used to model movement in a wide variety of contexts: from the movement of cells undergoing chemotaxis to the migration of animals. In a two-dimensional biased random walk, the diffusion about the mean drift position is entirely dependent on the moments of the angular distribution used to determine the movement direction at each step. Here we consider biased random walks using several different angular distributions and derive expressions for the diffusion coefficients in each direction based on either a fixed or variable movement speed, and we use these to generate a probability density function for the long-time spatial distribution. We demonstrate how diffusion is typically anisotropic around the mean drift position and illustrate these theoretical results using computer simulations. We relate these results to earlier studies of swimming microorganisms and explain how the results can be generalized to other types of animal movement. 相似文献
66.
Differential movement patterns and site fidelity among trophic groups of reef fishes in a Hawaiian marine protected area 总被引:1,自引:1,他引:0
We tracked the long-term movements of 70 parrotfishes, surgeonfishes and goatfishes captured inside a small (1.3 km2) marine protected area (MPA: Kealakekua Bay Marine Life Conservation District, Hawaii) by implanting them with small transmitters
and deploying underwater monitoring devices inside the bay and along 100 km of the adjacent west Hawaii coastline. Individual
fish were detected inside Kealakekua Bay for up to 612 days but many were detected for much shorter periods (median = 52 days).
There were species-specific differences in the scale of movements and habitats used, but most fish utilized between 0.2 and
1.6 km of coastline, and individuals of each species showed some degree of diel habitat shift. A wide variety of reef fishes
captured inside the MPA swam back and forth across an MPA boundary intersecting continuous reef (i.e., this boundary was porous
to reef fish movements), but only 1 of 11 species tagged crossed a wide sandy channel inside Kealakekua Bay suggesting that
this feature may function as a natural barrier to movements. Results indicate relatively small MPAs (<2 km of coastline) could
provide effective, long-term protection for multi-species assemblages of reef fishes provided that boundaries are situated
along major habitat breaks (e.g., large sand channels between reefs) that may serve as natural barriers to reef fish movements.
It is crucial that a multi-species approach be used when assessing MPA effectiveness. 相似文献
67.
Magnago Rachel Faverzani de Alcântara Braglia Thiago de Aguiar Ana Carolina Baungarten Polyana Mendonça Bruno Afonso Büchele Silva Heloisa Regina Turatti Egert Paola Girotto Edivandro Júnior Américo Cruz Parma Gabriel Oscar Cremona 《Journal of Material Cycles and Waste Management》2021,23(3):1126-1140
Journal of Material Cycles and Waste Management - This article aims to study the mechanical strength and fire resistance of polyurethane/cement (PuCem) composites containing glass sludge and sludge... 相似文献
68.
Rachel L. McDaniel Michelle L. Soupir Ross B. Tuttle Amy E. Cervantes 《Journal of the American Water Resources Association》2013,49(2):319-327
Abstract: Water‐quality standards have been placed on fecal indicator organisms such as Escherichia coli in an attempt to limit the concentrations in water bodies. Cattle can be a significant source of bacteria to water systems, particularly when they are allowed direct access to streams. A flume study was conducted to quantify the effect and understand the transport of E. coli from directly deposited cattle manure. Five steady‐state flows, ranging from 0.00683 to 0.0176 m3/s, were studied and loads from a single cowpie exceeded the U.S. Environmental Protection Agency’s recommended water‐quality standards (235 CFU/100 ml) at each flow over the hour study period. Average E. coli concentrations ranged from 102 to 105 CFU/100 ml over the hour sampling period for all flows. High spatial variations in E. coli concentrations were often seen at each sampling time, with higher concentrations typically at the bottom of the flume. E. coli resuspension was initially greater at 0.5 min after deposition, for the lowest flow (105 CFU/m2/s); however, resuspension rates became similar over time, on the order of 103 CFU/m2/s. This study demonstrates that the concentrations of E. coli can vary over the water column, and therefore grab samples may inaccurately measure bacteria concentrations and loads in streams. In addition, resuspension rates were often high, so the incorporation of this process into water‐quality models is important for bacteria prediction. 相似文献
69.
The open space conservation sub-division offers an alternative to large-lot residential sub-divisions often seen as the culprit when urban sprawl transforms rural landscapes. Homes are sited on somewhat smaller lots, preserving natural areas for the local residents who share ownership of these communal areas and assume responsibility for their management. The article focuses on the experiences of residents of 13 relatively new open space communities. The interviews revealed that most of the communities have already confronted conflicting values with respect to natural areas, low resident participation and challenges in accessing appropriate information. While the open space conservation design holds great promise as a tool for innovative approaches to managing residential growth, it also calls for ways to anticipate and assist communities in caring for their local environment. Recommendations are offered for planning professionals based upon the experience of these open space community residents. 相似文献
70.
Adaptive governance is advanced as a potent means of addressing institutional fit of natural resource systems with prevailing modes of political–administrative management. Its advocates also argue that it enhances participatory and learning opportunities for stakeholders over time. Yet an increasing number of studies demonstrate real difficulties in implementing adaptive governance ‘solutions’. This paper builds on these debates by examining the introduction of adaptive governance to water management in Chiang Mai province, north-west Thailand. The paper considers, first, the limitations of current water governance modes at the provincial scale, and the rationale for implementation of an adaptive approach. The new approach is then critically examined, with its initial performance and likely future success evaluated by (i) analysis of water stakeholders’ opinions of its first year of operation; and (ii) comparison of its governance attributes against recent empirical accounts of implementation difficulty and failure of adaptive governance of natural resource management more generally. The analysis confirms the potentially significant role that the new approach can play in brokering and resolving the underlying differences in stakeholder representation and knowledge construction at the heart of the prevailing water governance modes in north-west Thailand. 相似文献