Temporal trends in agricultural water use and the relationships to hydroclimatic factors in the High Plains aquifer region

The High Plains aquifer (HPA) is the primary water source for agricultural irrigation in the US Great Plains. The water levels in many locations of the aquifer have declined steadily over the past several decades because the rate of water withdrawals exceeds recharge, which has been a serious concern to the water resources management in the region. We evaluated temporal trends and variations in agricultural water use and hydroclimatic variables including precipitation, air temperature, reference evapotranspiration, runoff, groundwater level, and terrestrial water storage across the HPA region for different periods from 1985 to 2020 at the grid, county, or region scale. The results showed that water withdrawals decreased from 21.3 km³/year in 1985 to 18.2 km³/year in 2015, while irrigated croplands increased from 71,928 km² in 1985 to 78,464 km² in 2015 in the entire HPA. The hydroclimatic time-series showed wetting trends in most of the northern HPA, but drying and warming trends in the southern region from 1985 to 2020. The groundwater level time-series indicated flat trends in the north, but significant declining in the central and southern HPA. Trends in irrigation water withdrawals and irrigation area across the HPA were controlled by the advancement of irrigation systems and technologies and the management of sustainable water use, but also were affected by dynamical changes in the hydroclimatic conditions.     

Determination of 27 pharmaceuticals and personal care products (PPCPs) in water: The benefit of isotope dilution

• Isotope dilution method was developed for the determination of 27 PPCPs in water. • The established method was successfully applied to different types of water samples. • The correction effect of corresponding 27 ILSs over 70 d was investigated. • Benefit of isotopic dilution method was illustrated for three examples. Pharmaceuticals and personal care products (PPCPs) are a unique group of emerging and non-persistent contaminants. In this study, 27 PPCPs in various water samples were extracted by solid phase extraction (SPE), and determined by isotope dilution method using liquid chromatography coupled to tandem triple quadruple mass spectrometer (LC-MS/MS). A total of 27 isotopically labeled standards (ILSs) were applied to correct the concentration of PPCPs in spiked ultrapure water, drinking water, river, effluent and influent sewage. The corrected recoveries were 73%–122% with the relative standard deviation (RSD)<16%, except for acetaminophen. The matrix effect for all kinds of water samples was<22% and the method quantitation limits (MQLs) were 0.45–8.6 ng/L. The developed method was successfully applied on environmental water samples. The SPE extracts of spiked ultrapure water, drinking water, river and wastewater effluent were stored for 70 days, and the ILSs-corrected recoveries of 27 PPCPs were obtained to evaluate the correction ability of ILSs in the presence of variety interferences. The recoveries of 27 PPCPs over 70 days were within the scope of 72%–140% with the recovery variation<37% in all cases. The isotope dilution method seems to be of benefit when the extract has to be stored for long time before the instrument analysis.     

宁波月湖的水质改善与生态修复

随着浙江"五水共治"工作的深化,宁波作为浙江"五水共治"的中坚力量,始终把"五水共治"作为全市工作的首要任务和突破重点。自1999年进行清淤后,月湖水质得到短期改善,然而治标不治本的治理措施,并没有让月湖水质得到根本改善。因此,对月湖进行科学有效的生态修复,针对性地处理水污染问题,使之重新焕发活力具有十分重要的意义。     

江苏省太湖流域水生态健康评估的初步实践及展望

阐述了水生态健康的内涵与意义,从江苏省率先在太湖流域开展水生态环境功能分区管理的顶层设计,构建以水生态健康指标为核心的水生态健康评估技术体系,地方对照水生态环境功能区划的水生态分级管控目标开展的应用与实践结果等3个方面,回顾了江苏省太湖流域水生态健康评估工作的主要进展,提出了完善水生态健康评估技术体系和推进流域水生态健康评估工作的建议。     

瑞典的水环境保护经验及对我国的启示

介绍了瑞典的水环境保护法规政策、水环境保护机构、污水处理体系及其在水环境保护方面的特色做法。结合目前我国水环境管理所处的阶段,从顶层设计、宣传教育、项目管理、污染防治等方面,总结了瑞典经验对我国水环境保护工作的启示。     

A framework for allocating conservation resources among multiple threats and actions

Land managers decide how to allocate resources among multiple threats that can be addressed through multiple possible actions. Additionally, these actions vary in feasibility, effectiveness, and cost. We sought to provide a way to optimize resource allocation to address multiple threats when multiple management options are available, including mutually exclusive options. Formulating the decision as a combinatorial optimization problem, our framework takes as inputs the expected impact and cost of each threat for each action (including do nothing) and for each overall budget identifies the optimal action to take for each threat. We compared the optimal solution to an easy to calculate greedy algorithm approximation and a variety of plausible ranking schemes. We applied the framework to management of multiple introduced plant species in Australian alpine areas. We developed a model of invasion to predict the expected impact in 50 years for each species-action combination that accounted for each species’ current invasion state (absent, localized, widespread); arrival probability; spread rate; impact, if present, of each species; and management effectiveness of each species-action combination. We found that the recommended action for a threat changed with budget; there was no single optimal management action for each species; and considering more than one candidate action can substantially increase the management plan's overall efficiency. The approximate solution (solution ranked by marginal cost-effectiveness) performed well when the budget matched the cost of the prioritized actions, indicating that this approach would be effective if the budget was set as part of the prioritization process. The ranking schemes varied in performance, and achieving a close to optimal solution was not guaranteed. Global sensitivity analysis revealed a threat's expected impact and, to a lesser extent, management effectiveness were the most influential parameters, emphasizing the need to focus research and monitoring efforts on their quantification.     

HUD状态下飞行员视觉注意资源分配机制研究

为了解决平视显示器（Head Up Display,HUD）飞行中的注意资源分配问题，基于飞行模拟器，设计双作业飞行任务开展相关研究。基于事件相关电位（Event Related Potential，ERP）技术，选取行为绩效和P300成分为评价指标，采用oddball模式，在双作业飞行任务条件下开展实验研究。结果表明:随主任务难度的增加，主、辅任务的作业绩效均显著下降，被试者对HUD上异常信息的正确操作率降低，且反应时间延长；随主任务难度的增加，由辅任务所诱发的P300的波幅显著降低。在实验结果的基础上，最终提出了HUD状态下飞行员视觉注意资源分配机制。     

气相色谱法测定水质中的内吸磷

优化了气相色谱法测定水质中的内吸磷,当取样量为100 m L时,内吸磷-O方法检出限为0. 30μg/L,测定下限为1. 20μg/L;内吸磷-S方法检出限为0. 80μg/L,测定下限为3. 20μg/L。内吸磷-O和内吸磷-S标准曲线线性良好,相关系数分别为0. 999 2和0. 999 8。不同水质中内吸磷-O的加标回收率为90. 3%～104%,相对标准偏差为3. 6%～9. 2%;内吸磷-S的加标回收率为92. 1%～94. 9%,相对标准偏差为4. 6%～8. 7%。该方法灵敏度高,能有效分离内吸磷-O和内吸磷-S,同时能将内吸磷-O、内吸磷-S与其他有机磷农药类干扰物分离。     

便携式GC-MS仪快速测定水中硝基苯及其在应急监测中的应用

采用便携式GC-MS仪快速测定水中硝基苯,通过优化水中离子强度和顶空加热时间,使方法在0μg/L^300μg/L范围内线性良好,方法检出限为2.5μg/L。标准溶液6次测定结果的RSD为7.8%~10.9%,实际水样的加标回收率为80.7%~103%。同步测定试验表明,硝基苯与7种苯系物分离良好。与国标方法对比,该方法单个样品测定时间由2 h缩短为15 min。将该方法用于应急监测工作中,及时有效的数据可为污水处理及事故调查提供分析和研判依据。     

关于城市河流水污染防治技术应用和研究

随着我国经济的不断发展,各种工厂也大量的成立,而这也使得很多废弃物及废水被过度排放到湖泊与河流之中,进而导致其出现了严重的污染问题。污染不仅对人们的生活质量产生了影响,同时也对生态的平衡发展产生了很大的阻碍,业已经成为社会各界高度关注和重视的问题。基于此,本文围绕城市河流水污染的现状进行了分析,对于污染产生的原因也进行了阐述,针对城市河流水污染防治技术的应用也进行了探讨和研究,以期可以有效解决我国出现的河流水污染问题,进而为人们及社会营造一个全新、绿色的河流环境。