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121.
Towards Real‐Time Continental Scale Streamflow Simulation in Continuous and Discrete Space 下载免费PDF全文
Fernando R. Salas Marcelo A. Somos‐Valenzuela Aubrey Dugger David R. Maidment David J. Gochis Cédric H. David Wei Yu Deng Ding Edward P. Clark Nawajish Noman 《Journal of the American Water Resources Association》2018,54(1):7-27
The National Weather Service (NWS) forecasts floods at approximately 3,600 locations across the United States (U.S.). However, the river network, as defined by the 1:100,000 scale National Hydrography Dataset‐Plus (NHDPlus) dataset, consists of 2.7 million river segments. Through the National Flood Interoperability Experiment, a continental scale streamflow simulation and forecast system was implemented and continuously operated through the summer of 2015. This system leveraged the WRF‐Hydro framework, initialized on a 3‐km grid, the Routing Application for the Parallel Computation of Discharge river routing model, operating on the NHDPlus, and real‐time atmospheric forcing to continuously forecast streamflow. Although this system produced forecasts, this paper presents a study of the three‐month nowcast to demonstrate the capacity to seamlessly predict reach scale streamflow at the continental scale. In addition, this paper evaluates the impact of reservoirs, through a case study in Texas. Validation of the uncalibrated model using observed hourly streamflow at 5,701 U.S. Geological Survey gages shows 26% demonstrate PBias ≤ |25%|, 11% demonstrate Nash‐Sutcliffe Efficiency (NSE) ≥ 0.25, and 6% demonstrate both PBias ≤ |25%| and NSE ≥ 0.25. When evaluating the impact of reservoirs, the analysis shows when reservoirs are included, NSE ≥ 0.25 for 56% of the gages downstream while NSE ≥ 0.25 for 11% when they are not. The results presented here provide a benchmark for the evolving hydrology program within the NWS and supports their efforts to develop a reach scale flood forecasting system for the country. 相似文献
122.
Dale M. Jefferson Keith A. Hobson Brandon S. Demuth Maud C. O. Ferrari Douglas P. Chivers 《Die Naturwissenschaften》2014,101(4):291-303
Tadpoles show considerable behavioral plasticity. When population densities become high, tadpoles often become cannibalistic, likely in response to intense competition. Conspecific tissues are potentially an ideal diet by composition and should greatly improve growth and development. However, the potential release of alarm cues from the tissues of injured conspecifics may act to deter potential cannibals from feeding. We conducted multiple feeding experiments to test the relative effects that a diet of conspecifics has on tadpole growth and development. Results indicate that while conspecific tissues represent a better alternative to starvation and provide some benefits over low-protein diets, such a diet can have detrimental effects to tadpole growth and/or development relative to diets of similar protein content. Additionally, tadpoles raised individually appear to avoid consuming conspecific tissues and may continue to do so until they suffer from the effects of starvation. However, tadpoles readily fed upon conspecific tissues immediately when raised with competitors. These results suggest that cannibalism may occur as a result of competition rather than the specific quality of available diets, unless such diets lead to starvation. 相似文献
123.
Litao Wang Carey Jang Yang Zhang Kai Wang Qiang Zhang David Streets Joshua Fu Yu Lei Jeremy Schreifels Kebin He Jiming Hao Yun-Fat Lam Jerry Lin Nicholas Meskhidze Scott Voorhees Dale Evarts Sharon Phillips 《Atmospheric environment (Oxford, England : 1994)》2010,44(28):3442-3448
Under the 11th Five Year Plan (FYP, 2006–2010) for national environmental protection by the Chinese government, the overarching goal for sulfur dioxide (SO2) controls is to achieve a total national emissions level of SO2 in 2010 10% lower than the level in 2005. A similar nitrogen oxides (NOx) emissions control plan is currently under development and could be enforced during the 12th FYP (2011–2015). In this study, the U.S. Environmental Protection Agency (U.S.EPA)’s Community Multi-Scale Air Quality (Models-3/CMAQ) modeling system was applied to assess the air quality improvement that would result from the targeted SO2 and NOx emission controls in China. Four emission scenarios — the base year 2005, the 2010 Business-As-Usual (BAU) scenario, the 2010 SO2 control scenario, and the 2010 NOx control scenario—were constructed and simulated to assess the air quality change from the national control plan. The Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) was applied to generate the meteorological fields for the CMAQ simulations. In this Part I paper, the model performance for the simulated meteorology was evaluated against observations for the base case in terms of temperature, wind speed, wind direction, and precipitation. It is shown that MM5 model gives an overall good performance for these meteorological variables. The generated meteorological fields are acceptable for using in the CMAQ modeling. 相似文献
124.
Andrea Gori Sergio Rossi Elisa Berganzo Joan Lluis Pretus Mark R. T. Dale Josep-Maria Gili 《Marine Biology》2011,158(1):143-158
Most of the current knowledge on Mediterranean gorgonians is restricted to investigations of those populations found within
shallow sublittoral waters, and only limited data are available for populations located below scuba depth. To overcome this
lack of information, the occurrence and abundance of the gorgonians Eunicella singularis, Paramuricea clavata, and Leptogorgia sarmentosa were investigated in northwestern Mediterranean benthic communities over a wide geographical (60 km of coastline) and bathymetrical
(0–70 m deep) extent using a remotely operated vehicle (ROV). The greatest occurrence and abundances of E. singularis and P. clavata were concentrated in areas that are directly exposed to strong near-bottom currents. E. singularis was the most common and abundant species and displayed great plasticity and amplitude in its environmental preferences. Conversely,
P. clavata showed a very patchy distribution that was associated with vertical rocky walls. Only isolated colonies of L. sarmentosa were observed in the study area. Hot spots of abundance of E. singularis and P. clavata were identified below a depth of 40 m, which demonstrates the importance of studying the distribution of benthic species
over a wide geographical and bathymetrical extent. 相似文献
125.
The honesty of ornamental signals of quality is often argued to be enforced via costs associated with testosterone. It is
still poorly understood, however, how seasonal variation of testosterone within individuals is related to the timing and extent
of ornament development. Here, we studied inter- and intra-individual variability of plasma testosterone levels in a population
of 150 captive male house sparrows (Passer domesticus) through the course of a full year. We further analyzed the relationship between plasma testosterone levels and two sexually
dimorphic ornaments: badge size and bill coloration. Also, because of a known negative relation between molt and circulating
testosterone levels, we analyzed the relationship between ornamentation and molt status during the fall. We found that testosterone
levels increased towards the breeding season and decreased before the onset of annual molt. However, within individuals, relative
testosterone titers demonstrated low repeatability between seasons. Plasma testosterone levels were not correlated with badge
size in any season but were correlated strongly with bill coloration during all periods, except the breeding season when variation
in bill color was low. Finally, we found that bill coloration strongly correlated with molt status during fall. Our results
indicate that bill coloration, not badge size, is the best ornamental indicator of a “running average” of male testosterone
in house sparrows and therefore the best potential indicator of qualities and/or behavioral strategies associated with testosterone. 相似文献
126.
Cameron “Dale” Bass Martin Davis Mark “Steve” Rountree Robert M. Harris Ellory Sanderson 《International journal of occupational safety and ergonomics》2013,19(4):347-361
To reduce human casualties associated with explosive ordnance disposal, a wide range of protective wear has been designed to shield against the blast effects of improvised explosive devices and munitions. In this study, 4 commercially available bomb suits, representing a range of materials and armor masses, were evaluated against 0.227 and 0.567 kg of spherical C-4 explosives to determine the level of protection offered to the head, neck, and thorax.A Hybrid III dummy, an instrumented human surrogate [1], was tested with and without protection from the 4 commercially available bomb suits. 20 tests with the dummy torso mounted to simulate a kneeling position were performed to confirm repeatability and robustness of the dummies, as well as to evaluate the 4 suits. Correlations between injury risk assessments based on past human or animal injury model data and various parameters such as bomb suit mass, projected area, and dummy coverage area were drawn. 相似文献
127.
Rebecca A. Efroymson Virginia H. Dale Keith L. Kline Allen C. McBride Jeffrey M. Bielicki Raymond L. Smith Esther S. Parish Peter E. Schweizer Denice M. Shaw 《Environmental management》2013,51(2):291-306
Indicators of the environmental sustainability of biofuel production, distribution, and use should be selected, measured, and interpreted with respect to the context in which they are used. The context of a sustainability assessment includes the purpose, the particular biofuel production and distribution system, policy conditions, stakeholder values, location, temporal influences, spatial scale, baselines, and reference scenarios. We recommend that biofuel sustainability questions be formulated with respect to the context, that appropriate indicators of environmental sustainability be developed or selected from more generic suites, and that decision makers consider context in ascribing meaning to indicators. In addition, considerations such as technical objectives, varying values and perspectives of stakeholder groups, indicator cost, and availability and reliability of data need to be understood and considered. Sustainability indicators for biofuels are most useful if adequate historical data are available, information can be collected at appropriate spatial and temporal scales, organizations are committed to use indicator information in the decision-making process, and indicators can effectively guide behavior toward more sustainable practices. 相似文献
128.
129.
An Hui Razzaq Asif Nawaz Ahsan Noman Sohail M. Khan Syed Abdul Rehman 《Environmental science and pollution research international》2021,28(37):51022-51045
Environmental Science and Pollution Research - The Belt and Road initiative (BRI) mainly relies on the traditional and underdeveloped logistical trade routes including the terrestrial and oceanic... 相似文献
130.
Matthew R. House Marvin R. Pyles Dale White 《Journal of the American Water Resources Association》2005,41(1):209-217
ABSTRACT: Stream crossings designed to simulate a natural streambed inside a culvert are commonly used to meet criteria where fish passage is required. Currently, there has been little research that quantitatively examines the flow patterns within these streambed simulation culverts. A model is presented that estimates the percent of a cross section that is within the swimming ability of juvenile fish developed from velocity measurements on first‐generation stream simulation culverts — those culverts with a continuous gravel bed. The model, developed with regression techniques, uses physical and hydraulic parameters including discharge, total cross sectional area, Froude number, and relative roughness, and was tested directly against velocity distributions computed from field measurements and in a culvert design mode. Results were favorable, although larger percentage errors exist, particularly at small flow depths. The model appears to underestimate the percent of channel cross section at or below a limiting velocity, hence it is generally conservative in design mode. 相似文献