Development and Testing of a Physically Based Model of Streambank Erosion for Coupling with a Basin‐Scale Hydrologic Model SWAT

A comprehensive streambank erosion model based on excess shear stress has been developed and incorporated in the hydrological model Soil and Water Assessment Tool (SWAT). It takes into account processes such as weathering, vegetative cover, and channel meanders to adjust critical and effective stresses while estimating bank erosion. The streambank erosion model was tested for performance in the Cedar Creek watershed in north‐central Texas where streambank erosion rates are high. A Rapid Geomorphic field assessment (RAP‐M) of the Cedar Creek watershed was done adopting techniques developed by the Natural Resources Conservation Service (NRCS), and the stream segments were categorized into various severity classes. Based on the RAP‐M field assessment, erosion pin sites were established at seven locations within the severely eroding streambanks of the watershed. A Monte Carlo simulation was carried out to assess the sensitivity of different parameters that control streambank erosion such as critical shear stress, erodibility, weathering depth, and weathering duration. The sensitive parameters were adjusted and the model was calibrated based on the bank erosion severity category identified by the RAP‐M field assessment. The average observed erosion rates were in the range 25‐367 mm year^?1. The SWAT model was able to reasonably predict the bank erosion rates within the range of variability observed in the field (R² = 0.90; E = 0.78). Editor's note : This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.     

PRISM vs. CFSR Precipitation Data Effects on Calibration and Validation of SWAT Models

Precipitation is one of the most important drivers in watershed models. Our objective was to compare two sources of interpolated precipitation data in terms of their effect on calibration and validation of two Soil and Water Assessment Tool (SWAT) models. One model was a suburban watershed in metropolitan Atlanta, Georgia. The precipitation sources were Parameter‐elevation Relationships on Independent Slopes Model (PRISM) data on a 4‐km grid and climate forecast system reanalysis (CFSR) data on a 38‐km grid. The PRISM data resulted in a better fit to the calibration data (Nash Sutcliffe efficiency [NSE] = 0.64, Kling‐Gupta efficiency [KGE] = 0.74, p‐factor = 0.84, and r‐factor = 0.43) than the CFSR data (NSE = 0.47, KGE = 0.53, p‐factor = 0.67, and r‐factor = 0.39). Validation results were similar. Sensitive parameters were similar in both the PRISM and CFSR models, but fitted values indicated more rapid groundwater flow to the streams with the PRISM data. The same comparison was made in the Big Creek watershed located approximately 1,000 km away, in central Louisiana. Results were similar with a more responsive groundwater system indicating PRISM data may produce better predictions of streamflow because of a more accurate estimate of rainfall within a watershed or because of a denser grid. Our study implies PRISM is providing a better estimate than CFSR of precipitation within a watershed when rain gauge data are not available, resulting in more accurate simulations of streamflows at the watershed outlet. Editor's note: This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.     

混合振动试验在汽车电子装备中的应用和要点

环境试验方法国家标准试验Fi：振动 混合模式（GB/T2423.58-2008）已经发布。彩混合振动试验的《道路车辆电气及电子设备的环境条件和试验》国家标准（制订征求意见稿）已经公示。文内介绍了混合模式振动试验在汽车电子装备中的应用,以及混合模式振动试验的过程要素和试验的技术要点。     

混凝土结构使役环境中温度智能模拟LabVIEW软件设计

本项目结合湖北省科技计划自然科学基金项目“混凝土结构使役环境的智能模拟”,在WTST-150试验机硬件平台基础上,以LabVIEW8．5为开发平台,设计了一套混凝土结构使役环境中温度智能模拟LabVIEW软件,主要包括能初始化程序、温度采集与显示子程序、温度PID控制子程序、温度存储和查询子程序。经投入实验验证,该软件能实现实时曲线显示、温度控制、试验状态和保存试验数据、数据查询、手动加热、分配温度通道、PID控制参数整定、制冷、读入温度曲线等功能。具有实时在线循环检测、采集数据、响应快速等优点,并具有良好的故障诊断能力和可维护性以及超强的纠错能力。本软件完善了WTST-150试验机的温度控制系统,使其更加符合实际工况。     

Sexual conflict over fertilizations: female bluethroats escape male paternity guards

Extra-pair copulations create a potential for sexual conflict in pair-bonding birds. Here we report an experimental study of the bluethroat, Luscinia s. svecica, in which the throat ornament of males was blackened with Nyanzol D in order to reduce their sexual attractiveness and thus increase the sexual conflict over fertilizations. In an earlier study, we showed that males blackened before pairing had a lower success in attracting social mates than controls, whereas males blackened after pairing guarded their mates more intensely and sang less than controls. Here we add behavioural data from one more year on males blackened after pairing and corroborate our previous finding that the manipulation caused males to guard their mates more intensely and advertise less for additional mates. Blackened males did not suffer more intrusions from neighbouring males than did controls. Paternity analyses of the combined data set, using multilocus DNA fingerprinting and microsatellite typing, revealed that blackened males lost significantly more paternity than controls. There was also a tendency for blackened males to show a lower success in achieving extra-pair fertilizations. These results indicate that females have the upper hand in the sexual conflict over fertilizations, as females paired with unattractive males can achieve more extra-pair paternity despite the greater constraint posed by the intensified mate guarding. Still, within the blackened group, there were some indications that males guarding more intensely and singing less had higher paternity than males guarding less and singing more, suggesting a marginal positive effect of guarding for unattractive males. Male mate guarding must nevertheless be considered a best-of-a-bad-job strategy in this species. Received: 4 December 1997 / Accepted after revision: 14 June 1998     

Do female black-capped chickadees prefer high-ranking males as extra-pair partners?

Previous studies have shown that some female black-capped chickadees (Poecile atricapillus) solicit copulations from males that rank higher in winter flocks than their social mates, and extra-pair paternity in nests occurs commonly enough to be considered a potential female mating tactic. This study uses blood samples collected in 1992–1995 from 58 families of black-capped chickadees to test whether females with extra-pair offspring have chosen extra-pair sires higher in social rank than their mates. Paternity was assessed with multilocus DNA fingerprinting in 1992–1994 nests and with microsatellite and single-locus minisatellite DNA typing in 1995 nests. Seventeen of 58 nests (29.3%) contained young genetically mismatched with their social father. In 11 of 15 cases where the identity of the extra-pair male was known, the extra-pair male was dominant to the social father. Using data from 29 nests located in 1994 and 1995 for which we had the most data on relative ranks of males, high-ranking males had greater realized reproductive success than low-ranking males as a result of extra-pair fertilizations. There was no significant difference between the number of nests containing extra-pair young of females mated to low-ranked versus high-ranked males. Two nests in 1995 contained young either genetically mismatched with both social parents (intraspecific brood parasitism) or, in one nest, genetically mismatched with the social mother but not the social father (quasi-parasitism). The implications of female strategies acquiring genetic benefits through extra-pair copulations are discussed. Received: 7 July 1997 / Accepted after revision: 14 March 1998     

粉末涂料环境试验的重要性及方法

粉末涂料喷涂上工件后,涂层即被赋予了一定的物理化学性能,这些性能在外部自然环境中,经过一段时间会发生哪些变化,涂层最终失去效用要多长时间,哪些因素对涂层的破坏性最强等等,这些都是大家非常关注的。本文简单讨论了粉末涂料环境试验的重要性,介绍了一些实际应用中环境试验的方法及其评级标准。     

混合型防霉剂HFM-01在三防涂层中的应用研究

通过筛选试验而研配的混合型防霉剂ＨＦＭ－０１具有高效、低毒和安全的特点,在涂料中添加ＨＦＭ－０１可以有效提高涂层的三防性能。     

DEEP WELL DISPOSAL OF SECONDARY EFFLUENT IN DADE COUNTY,FLORIDA1

ABSTRACT: Data were obtained from drilling and testing of a test injection well for deep underground injection of waste water effluent from the proposed 50-million-gallon-per-day (mgd) South District Regional Wastewater Treatment Plant of the Miami-Dade Water and Sewer Authority, Dade County, Florida. The drilling operation progressed in stages, each stage coverting the strata to be sealed off by the 48-inch, 40-inch, 30-inch, and 20-inch casings, respectively. Total depth of the well is 3,200 feet. The top of the saline, cavernous, dolomitic Boulder Zone was found at 2,790 feet below the surface and is separated from the Floridan aquifer above by approximately 1,100 feet of confining limestone layers. These confining layers were determined, by packer testing, to be very effective. The transmissivity of the Boulder Zone was estimated to be 14 × 10⁶ gallons per day per foot (gpd/ft) from the data obtained from pump out tests. An 8,000-gallon-per-minute (gpm) injection test was conducted to confirm well performance under operating conditions. Based on all of the data obtained, it was concluded that underground injection into the Boulder Zone of secondary waste water effluent from the proposed treatment plant is feasible, both hydraulically and environmentally. A monitoring system was proposed to provide a record of the effects of injection on the subsurface environment.     

土壤电阻率测试常见问题的分析

土壤电阻率的测试方法目前运用较为广泛的是四极等距法(文纳四极法),该方法测试数据较准确,操作过程较为简单,但由于测试现场土壤状况非常复杂,若对测量仪器和原理不深入了解或测试场地选择不当,将无法得到准确的数据,同时在测试过程中,测试人员通常会遇到数据偏小或数据超过仪器量程而导致无法运用到具体的工程和评估计算中,为此对测试场地、仪器的选择,数据无法测出的问题,测试电极的埋设深度,测试电极"a"的选择等常见问题提出最佳解决办法。