Longitudinal analysis of bioaccumulative contaminants in freshwater fishes

The National Contaminant Biomonitoring Program (NCBP) was initiated in 1967 as a component of the National Pesticide Monitoring program. It consists of periodic collection of freshwater fish and other samples and the analysis of the concentrations of persistent environmental contaminants in these samples. For the analysis, the common approach has been to apply the mixed two-way ANOVA model to combined data. A main disadvantage of this method is that it cannot give a detailed temporal trend of the concentrations since the data are grouped. In this paper, we present an alternative approach that performs a longitudinal analysis of the information using random effects models. In the new approach, no grouping is needed and the data are treated as samples from continuous stochastic processes, which seems more appropriate than ANOVA for the problem.     

地下水脱砷技术的研究现状及发展趋势

为明确地下水脱砷技术研究现状及未来发展趋势,采用文献计量学方法统计分析了Web of Science（WoS）数据库中2008—2020年发表的关于地下水脱砷技术的文献资料,并从年度发文量、发文机构、发文期刊、发文作者以及论文关键词等方面进行分析。结果表明：WoS数据库中地下水脱砷技术方面的研究型论文共1 501篇,年度发文量总体呈上升趋势;中国、美国和印度为发文量排名前3的国家;共计1 503家研究机构、4 875名作者参与地下水脱砷技术研究,其中高等院校为主要研究机构,而高校教师与硕士、博士研究生则为研究的主力军;关键词分析表明,吸附和电絮凝技术是地下水脱砷的主流方法,其中零价铁材料作为吸附剂是贯穿2008—2020年的研究热点;通过突现分析得出,二元甚至多元氧化物和纳米复合材料的制备将成为未来地下水脱砷技术研究的热点方向。

     

长荡湖近61a降水量演化特征

基于王母观站和溧阳站1953~2013a系列年降水量资料,采用Spearman和Mann-Kendall非参数统计检验、连续小波变换等技术手段,分析了61a来长荡湖年降水量的演变特征。结果表明,长荡湖多年平均降水量为1 115.1 mm,年内降水量呈明显的季节性变化;年降水量总体呈减少趋势,但仍以正常年份居多,偏多与偏少年份相当;长荡湖湖区年降水量变化周期为9.5a;年降水量变化不存在突变。研究成果可为长荡湖湖区的洪水控制、水资源利用、水调度方案制订、应对气候变化提供科学依据。     

基于文献计量学的中国湿地碳循环研究进展

为探明中国湿地碳循环的研究现状及发展趋势,基于Web of Science（WoS）和CNKI数据库中2000—2020年发表的中国湿地碳循环研究的相关文献信息,运用文献计量学方法对年度发文量、引用频次、作者、国家、机构、期刊、关键词等进行分析,解析了国内外该领域的研究进展并对未来发展提出了建议。结果表明：2000—2020年共发表有关中国湿地碳循环领域文献2 998篇,WoS和CNKI数据库分别为1 120和1 878篇,年发文量呈现波动上升的趋势;WoS数据库中的文献涉及全球51个国家,其中中国发文量为1 075篇,占总发文量的95.98%;“湿地”“土壤有机碳”“甲烷释放”是中介中心性较高的关键词,是湿地碳循环研究的核心内容;Ecological Engineering和《生态学报》分别是该领域外文和中文文献的主要期刊载体;温室气体交换机制和通量、微生物对碳循环的影响、湿地土壤的碳生态化学计量特征、湿地碳循环与全球变化等是近5年来中国湿地碳循环研究的热点问题。计量分析结果有助于全面了解中国湿地碳循环研究现状及进展,为国内外的湿地碳研究提供参考。

     

ANALYSIS OF STREAMFLOW TRENDS AND THE EFFECTS OF CLIMATE IN PENNSYLVANIA, 1971 TO 20011

An understanding of temporal trends in total stream‐flow (TSF), base flow (BF), and storm runoff (RO) can help in the development of water management plans for watersheds and local communities. In this study, 47 streams across Pennsylvania that were unregulated and unaffected by karst environments or coal mining were studied for flow trends and their relationships to selected climate parameters for the period 1971 to 2001. LOWESS curves for annual flow showed that almost all of the selected streams in Pennsylvania had downward trends in total TSF, BF, and RO. Using a seasonal Mann‐Kendall analysis, downward trends were significant at an α= 0.05 level for 68, percent 70 percent, and 62 percent of the streams and at an α= 0.10 level for another 19, 17, and 13 percent of the streams for TSF, BF, and RO, respectively. The ratio of BF to TSF (RBS) had significant upward trends for 34 percent of the streams at an α= 0.05 level and for another 9 percent of the streams at an α= 0.10 level, indicating that TSF decreased relative to BF for more than 40 percent of the streams during the previous 30 years. Downward trends in TSF, BF, and RO were most common for the months of June, July, and December. Trend analyses using monthly and annual total precipitation and mean temperature showed some association between climate and the streamflow trends, but Spearman's correlation and partial Mann‐Kendall analyses revealed that the trends in TSF, BF, and RO could not be explained by trends in precipitation and temperature alone, and thus urbanization and development may have played a role.     

遥感监测沙尘暴的研究进展及趋势

沙尘暴是一种气象灾害,也是严重的生态环境问题.它对自然环境和经济社会的危害已越来越引起人类的重视.随着环境遥感的发展,运用遥感技术对沙尘暴进行监测是最有效的方法之一.文章通过对中国沙尘暴遥感监测研究的现状的概述以及对当前遥感应用的技术水平的分析,展望了未来遥感监测沙尘暴的发展趋势.     

战略环境评价的国际研究动向

战略环境评价是国际上近年来的研究热点,但就目前来看还没有对其形成统一的认识和理解。以近年来相关研究的文章和案例为基础,总结并阐述了国际上战略环境评价研究的3个明显的动向:以决策为目标的战略环境评价,以传统环境影响评价为基础的战略环境评价和与可持续发展战略结合的战略环境评价。     

中国地震灾害防御对策的进展及今后的发展趋势

本文详细的论述了地震灾害效应,并给出了地震灾害防御对策的准确概念。在总结中国近二十年地震灾害防御对策的基础上,给出了今后我国地震灾害防御对策的发展趋势,对于我国今后开展震害防御工作具有一定意义。     

“十一五”期间盖州市大气环境质量变化趋势分析

对盖州市＂十一五＂期间大气环境质量进行研究,采用Daniel趋势检验法定量分析该地区大气环境质量的变化规律与发展趋势,探讨污染成因与特征,并提出综合防治措施。     

Predictors of specialist avifaunal decline in coastal marshes

Coastal marshes are one of the world's most productive ecosystems. Consequently, they have been heavily used by humans for centuries, resulting in ecosystem loss. Direct human modifications such as road crossings and ditches and climatic stressors such as sea‐level rise and extreme storm events have the potential to further degrade the quantity and quality of marsh along coastlines. We used an 18‐year marsh‐bird database to generate population trends for 5 avian species (Rallus crepitans, Tringa semipalmata semipalmata, Ammodramus nelsonii subvirgatus, Ammodramus caudacutus, and Ammodramus maritimus) that breed almost exclusively in tidal marshes, and are potentially vulnerable to marsh degradation and loss as a result of anthropogenic change. We generated community and species trends across 3 spatial scales and explored possible drivers of the changes we observed, including marsh ditching, tidal restriction through road crossings, local rates of sea‐level rise, and potential for extreme flooding events. The specialist community showed negative trends in tidally restricted marshes (?2.4% annually from 1998 to 2012) but was stable in unrestricted marshes across the same period. At the species level, we found negative population trends in 3 of the 5 specialist species, ranging from ?4.2% to 9.0% annually. We suggest that tidal restriction may accelerate degradation of tidal marsh resilience to sea‐level rise by limiting sediment supply necessary for marsh accretion, resulting in specialist habitat loss in tidally restricted marshes. Based on our findings, we predict a collapse of the global population of Saltmarsh Sparrows (A. caudacutus) within the next 50 years and suggest that immediate conservation action is needed to prevent extinction of this species. We also suggest mitigation actions to restore sediment supply to coastal marshes to help sustain this ecosystem into the future.