Declines in migrant shorebird populations from a winter‐quarter perspective

Many long‐distance migrating shorebird (i.e., sandpipers, plovers, flamingos, oystercatchers) populations are declining. Although regular shorebird monitoring programs exist worldwide, most estimates of shorebird population trends and sizes are poor or nonexistent. We built a state‐space model to estimate shorebird population trends. Compared with more commonly used methods of trend estimation, state‐space models are more mechanistic, allow for the separation of observation and state process, and can easily accommodate multivariate time series and nonlinear trends. We fitted the model to count data collected from 1990 to 2013 on 18 common shorebirds at the 2 largest coastal wetlands in southern Africa, Sandwich Harbour (a relatively pristine bay) and Walvis Bay (an international harbor), Namibia. Four of the 12 long‐distance migrant species declined since 1990: Ruddy Turnstone (Arenaria interpres), Little Stint (Calidris minuta), Common Ringed Plover (Charadrius hiaticula), and Red Knot (Calidris canutus). Populations of resident species and short‐distance migrants increased or were stable. Similar patterns at a key South African wetland suggest that shorebird populations migrating to southern Africa are declining in line with the global decline, but local conditions in southern Africa's largest wetlands are not contributing to these declines. State‐space models provide estimates of population levels and trends and could be used widely to improve the current state of water bird estimates.     

我国废弃资源和废旧材料回收加工业发展探讨

近年来,作为我国工业经济的一支新军—废弃资源和废旧材料回收加工业正在持续快速发展,私营工业企业是该行业的主力军。《循环经济促进法》和相关政策法规的进一步实施,为该行业注入了新的生机活力,加快自主创新,提高资源综合利用水平,是该行业发展的主流。     

Nonstationarity: Flood Magnification and Recurrence Reduction Factors in the United States1

Vogel, Richard M., Chad Yaindl, and Meghan Walter, 2011. Nonstationarity: Flood Magnification and Recurrence Reduction Factors in the United States. Journal of the American Water Resources Association (JAWRA) 47(3):464‐474. DOI: 10.1111/j.1752‐1688.2011.00541.x Abstract: It may no longer be reasonable to model streamflow as a stationary process, yet nearly all existing water resource planning methods assume that historical streamflows will remain unchanged in the future. In the few instances when trends in extreme events have been considered, most recent work has focused on the influence of climate change, alone. This study takes a different approach by exploring trends in floods in watersheds which are subject to a very broad range of anthropogenic influences, not limited to climate change. A simple statistical model is developed which can both mimic observed flood trends as well as the frequency of floods in a nonstationary world. This model is used to explore a range of flood planning issues in a nonstationary world. A decadal flood magnification factor is defined as the ratio of the T‐year flood in a decade to the T‐year flood today. Using historical flood data across the United States we obtain flood magnification factors in excess of 2‐5 for many regions of the United States, particularly those regions with higher population densities. Similarly, we compute recurrence reduction factors which indicate that what is now considered the 100‐year flood, may become much more common in many watersheds. Nonstationarity in floods can result from a variety of anthropogenic processes including changes in land use, climate, and water use, with likely interactions among those processes making it very difficult to attribute trends to a particular cause.     

“十一五”期间新疆湖库水质变化趋势及原因分析

通过对新疆湖库“十一五”期间水质变化趋势的分析,结合五年间地方政府采取的综合污染防治措施,分析了水质变化的原因,并提出相应对策建议,以便更好地推进新疆湖库水污染防治工作。     

基于变权欧式距离模型的大气环境变化趋势分析

2008年以来德化县在城区推动陶瓷企业使用清洁能源,淘汰了污染较严重的燃料。本文通过建立变权欧式距离模型,分析德化县2005年至2009年改用清洁能源前后城区环境空气变化趋势。变权欧式距离模型评价结果表明,这5年的德化县城区大气环境质量较好,PM10是城区大气环境的主要污染物。自2008年德化县城区陶瓷企业改用清洁能源后,PM10的权重系数略有降低,大气环境质量级别R也变小,城区大气环境质量得到改善。     

老边区环境空气质量综合评价

根据“十一五”期间老边区环境空气质量监测情况,采用环境空气污染负荷系数法综合指数法,通过污染物负荷系数的计算,确定老边区环境空气主要污染物和次要污染物,并对老边区环境空气质量进行简评与分析。     

基于卫星和地面观测的2013年以来我国臭氧时空分布及变化特征

采用卫星和地面观测臭氧（O₃）浓度,分析2013年以来我国O₃的时空分布和年际变化特征.卫星观测对流层O₃总量和地面观测O₃浓度分布相互印证,我国高浓度O₃主要分布在东部人口密集、经济发达的区域,并且呈现夏季高、冬季低的季节分布趋势.4个重点关注城市（北京、上海、广州、成都）O₃日变化均呈现单峰分布,最高值在每日15：00~16：00.统计分析发现,4个城市除上海市之外,其他3个城市O₃浓度在周末和工作日没有显著差别,表明O₃的"周末效应"减弱.2013年4月~2018年6月,我国地面观测O₃浓度呈现明显上升趋势.2014~2017年,北京、上海和成都市近地面O₃浓度分别以2.36、3.3和3.6 μg·（m³·a）^-1的速度显著上升.4个城市2014~2017年O₃超标天数占比分别为17.2%（北京）、10.7%（上海）、8.8%（广州）和11.2%（成都）,北京市O₃超标天数最多、超标期间O₃浓度最高,O₃污染最为严重.     

炼油碱渣废水中硫化物去除技术的研究进展

简单介绍了炼油碱渣废水的来源及特点,综述了近年来炼油碱渣废水中硫化物的去除技术(包括沉淀技术、氧化技术、生物技术、超声波技术、电化学技术等)的研究进展。结合各技术的特点分析指出:以催化氧化为核心,以高效、经济、条件缓和为主要目标的组合工艺的优化与集成以及新型催化剂的研发,是炼油碱渣废水中硫化物去除技术的发展趋势。     

Multiscale Analysis of Hydrology in a Mountaintop Mine‐Impacted Watershed

In the Appalachian region of the eastern United States, mountaintop removal mining (MTM) is a dominant driver of land‐cover change, impacting 6.8% of the largely forested 4.86 million ha coal fields region. Recent catastrophic flooding and documented biological impairment downstream of MTM has drawn sharp criticism to this practice. Despite its extent, scale, and use since the 1970s, the impact of MTM on hydrology is poorly understood. Therefore, the goal of this study was a multiscale evaluation to establish the nature of hydrologic impacts associated with MTM. To quantify the extent of MTM, land‐cover change over the lifetime of this practice is estimated for a mesoscale watershed in southern West Virginia. To assess hydrologic impacts, we conducted long‐term trend analyses to evaluate for systematic changes in hydrology at the mesoscale, and conducted hydrometric and response time modeling to characterize storm‐scale responses of a MTM‐impacted headwater catchment. Results show a general trend in the conversion of forests to mines, and significant decreases in maximum streamflow and variability, and increases in base‐flow ratio attributed to valley fills and deep mine drainage. Decreases in variability are shown across spatial and temporal scales having important implications for water quantity and quality. However, considerable research is necessary to understand how MTM impacts hydrology. In an effort to inform future research, we identify existing knowledge gaps and limitations of our study.     

长江口南汇东滩淤涨演变分析

根据1983－1999年历年地形测图和1999年4月-2000年3月潮滩断面定位观测的相对高程记录，结合潮滩水文泥沙观测资料，对长江口南汇东滩的淤涨演变进行分析。结果表明，不断淤涨的平缓潮滩在风暴浪和常浪作用下发生相就应的突变和渐变，并且常浪对滩面起洗平作用，而风暴浪对滩面起掀掘作用。潮流携带细颗粒泥沙塑造潮滩，通过上、下滩水体含沙量之差可计算潮滩的堆积速率，从滩坡平衡原理可计算潮滩水平扩展趋势。计算结果得到南汇潮滩堆积速率为4．5cm/a，淤涨速率40－50m／a，写实测资料相符。