基于R语言的非点源颗粒态磷指数构建及应用——以丘陵红壤区小流域为例

以南方丘陵红壤区典型小流域为例,构建了基于R语言的流域非点源颗粒态磷污染指数并进行应用.结果表明,（1）流域土壤侵蚀模数在0.7~15244.2t/（km²·a）之间,超出南方丘陵红壤区容许土壤侵蚀量的区域占流域面积59%;平均非点源颗粒态磷产生强度为0.86kg/hm²,超出非点源磷流失阈值的区域占流域面积14%.流域侵蚀等级以微、轻度为主,但中度及以上强度区域以较小的面积（7.2%）贡献了较大比例的流域侵蚀产生量（35%）和输出量（43%）、以及非点源颗粒态磷输出量（31%）.（2）识别的关键源区占流域面积14%,贡献了65%和58%的侵蚀土壤和颗粒态磷输出负荷;主要分布在近河道的坡地（<25°,水文距离≤800m）,林地、耕地、园地是主要土地利用类型组成.（3）过量施肥导致的土壤磷素富集、强降雨条件下低丘缓坡地带的高易蚀性是关键源区形成的主因.研究进一步对关键源区进行分类分区,提出了以水土保持、配方施肥、工程治理为核心的非点源颗粒态磷污染治理组合措施.研究为丘陵红壤区流域非点源颗粒态磷污染的防治提供了较为系统完善的思路.     

村镇水土环境中抗生素的污染特征及来源解析

采用固相萃取-高效液相色谱-串联质谱法（SPE-HPLC-MS/MS）测定并分析了辽宁省岫岩县3个典型村镇水土环境中6类34种抗生素的污染水平和分布特征.结果表明,6类抗生素在3个村镇水土环境中部分或全部检出.地表水中34种抗生素总体残留浓度为（0.287~40.675） ng/L,人类活动和村镇畜禽养殖会导致水体中抗生素残留浓度偏高;土壤环境中34种抗生素总体残留浓度为（0.630~115.363） ng/g,不同土地使用类型下抗生素残留浓度规律为：畜禽养殖区>农业种植区>居民居住区>矿业开发区,畜禽粪便是土壤中抗生素污染的主要来源.此外,水土环境中抗生素的残留浓度与多种环境因子相关性明显.     

传统农区粮食生产转型机制及其安全效应——基于乡村空间治理视角

转型期乡村空间利用问题成为影响粮食安全的重要因素,开展乡村空间综合治理成为推动粮食生产有序转型的重要动力。系统分析乡村空间治理导向的粮食生产转型机制及其安全效应,有益于完善粮食安全的理论和实践分析。本文以乡村空间治理导向的粮食生产转型内在机制分析为突破,结合平原农区典型案例进行实证研究,并探讨了乡村空间治理与粮食安全的内在关系。主要结论如下：（1）乡村空间的不合理利用是限制粮食生产高效运转的重要因素。（2）乡村空间“物质—权属—组织”治理,通过改变粮食生产所需的基础条件达到优化粮食生产的目的,推动粮食生产朝着规模化、高效化、绿色化和公正化转型。（3）香埠村空间治理显著改善了该村粮食生产条件,有效协调粮食安全保障与乡村转型发展的交互作用关系。（4）乡村空间治理能力现代化是提升粮食安全保障能力的重要手段和途径。传统农区开展乡村空间“物质—权属—组织”的综合治理,有利于保障转型期粮食安全,落实“藏粮于地”战略,具有现实意义。     

基于生态网络—人类干扰的国土空间生态修复优先区诊断——以长株潭城市群为例

基于整体保护与系统治理思维诊断生态修复优先区,是科学有序推进国土空间生态修复的重要抓手。以长株潭城市群为例,利用人类足迹定量评估人类活动对生态系统的干扰强度,在此基础上通过最小累积阻力模型、电路理论、移动窗口搜索法等,识别生态网络并诊断人类干扰致其结构与功能受损的关键区域为生态修复优先区。研究表明：（1）城市群人类干扰整体呈核心—边缘递减的圈层式分布,且西高东低,北高南低;（2）识别区域生态网络,其中包含140个生态源地斑块以及307条源间潜在生态廊道;（3）诊断得到生态源地修复优先区共计867.17 km²,生态廊道修复优先区共计97.83 km,生态夹点修复优先区共计40处,从面线点相结合角度提出消除或弱化人类干扰的修复策略。研究能为新时代区域国土空间生态修复的规划编制与实施工作提供空间指引。     

京津冀及周边MAIAC AOD和PM2.5质量浓度特征及相关性分析

基于2014~2018年京津冀及周边地区MAIAC AOD和PM_2.5质量浓度数据,探讨AOD和PM_2.5质量浓度的时空差异,并利用线性回归探讨两者之间的相关性.结果表明,PM_2.5日均浓度超标天数分别占33%和57%（执行世界卫生组织IT.1和IT.2日均标准值）,污染较为严重.Terra、Aqua MAIAC AOD和PM_2.5年均浓度均呈下降趋势,PM_2.5浓度呈现出冬春季高、夏秋季低的特点,而Terra、Aqua AOD则表现为春夏季高、秋冬季低.PM_2.5及AOD的季均和年均浓度均呈现"北低南高"的区域分布特征,高值区主要位于河北南部、山西南部、山东西部以及河南北部,低值区主要位于山西北部、河北北部以及山东东部.PM_2.5年均浓度介于27~99μg·m^-3,AOD年均值介于0.20~0.69.Aqua AOD与PM_2.5浓度的相关性更高,且不同季节Terra、Aqua AOD与PM_2.5相关性差异显著,总体均表现为春冬季良好,夏秋季相对较差.对卫星AOD进行垂直和湿度订正后,其与PM_2.5的相关性显著提高.     

生态功能区建设中政府行为的价值取向和评判标准

生态功能区建设中的政府行为,不仅涉及发展困境与生态环境保护间矛盾的协调问题,更涉及维护经济社会和资源的可持续发展等问题。因此,生态功能区建设中政府行为需要确立以发展生态经济为核心、以强化生态服务为根本、以塑造生态文化为基础、以构建生态制度为保障和以维护生态安全为目标的价值取向,并从合法性、合理性、效益性和发展性等四个方面的标准,对政府行为的优劣进行全方位、多层次、全面而系统的评判。     

农村环境监测存在的问题及建议——以敖其村为例

通过对敖其村地表水、饮用水源地、环境空气、土壤进行调查,发现作物种类改变、监测点位变化、专业人员匮乏、经费来源紧张等问题制约了农村环境质量监测工作的开展,建立固定监测点位、加强人员培训、加大经费投入等措施可以有效解决农村环境质量监测中存在的问题,保证监测工作的顺利开展和进行。     

Mitigating the Effects of Landscape Development on Streams in Urbanizing Watersheds

This collaborative study examined urbanization and impacts on area streams while using the best available sediment and erosion control (S&EC) practices in developing watersheds in Maryland, United States. During conversion of the agricultural and forested watersheds to urban land use, land surface topography was graded and vegetation was removed creating a high potential for sediment generation and release during storm events. The currently best available S&EC facilities were used during the development process to mitigate storm runoff water quality, quantity, and timing before entering area streams. Detailed Geographic Information System (GIS) maps were created to visualize changing land use and S&EC practices, five temporal collections of LiDAR (light detection and ranging) imagery were used to map the changing landscape topography, and streamflow, physical geomorphology, and habitat data were used to assess the ability of the S&EC facilities to protect receiving streams during development. Despite the use of the best available S&EC facilities, receiving streams experienced altered flow, geomorphology, and decreased biotic community health. These impacts on small streams during watershed development affect sediment and nutrient loads to larger downstream aquatic ecosystems such as the Chesapeake Bay.     

On‐Site Exposure to Treated Wastewater Effluent Has Subtle Effects on Male Fathead Minnows and Pronounced Effects on Carp

This study tested the hypotheses that (1) exposure to treated Water Reclamation Plant (WRP) effluent will induce biological effects in exposed fish that are consistent with environmental estrogen (EE) exposure; and (2) seasonal differences in effluent composition will moderate biological effects. We conducted seven on‐site exposures using a mobile laboratory. Total estrogenicity of effluents was 10‐ to 20‐fold higher during spring than in fall. Common EEs including steroid estrogens, alkylphenols, and bisphenol‐A were ubiquitous. An unusual spike in total estrogenicity identified a combined sewer overflow event. Fathead minnows (Pimephales promelas) responded to exposure with subtle changes in vitellogenin concentrations and secondary sex characteristics. An opportunity to assess a common carp (Cyprinus carpio) population permanently sustained inside the Stickney WRP revealed pronounced exposure effects, but also the resilience of biological organisms even under long‐term exposure. In contrast to other studies, no histopathological changes were found. The mobile exposure laboratory proved capable of maintaining U.S. Environmental Protection Agency‐recommended exposure conditions while providing flexibility for rapid deployment at multiple sites with minimal operational disruption. Further studies using this platform hold promise to resolve the convoluted interactions between complex effluents and inherent biological complexity.     

Inspiring England's urban fringes: multi-functionality and planning

The urban fringe has been described as 'planning's last frontier'; a zone of transition and interface between town and country where a broad variety of land uses and activities come together, and where development pressure is often intense. In this paper, we argue that the urban fringe possesses special characteristics, making it more than simply a transitional landscape. These characteristics centre on patterns of land use, biodiversity and leisure/development opportunity which are unique to the urban edge and to land extending away from built-up areas. The uniqueness, diversity and particular dynamics of the urban fringe demands a special brand of planning and management response. Therefore we suggest that the principle of 'multi-functionality' provides a framework for action, showing how diversity can be managed and supported. Through brief case studies, we demonstrate how functional interactions at the urban fringe might be promoted in the future.