Testing the importance of accurate meteorological input fields and parameterizations in atmospheric transport modelling using dream - validation against ETEX-1

A tracer model, the DREAM, which is based on a combination of a near-range Lagrangian model and a long-range Eulerian model, has been developed. The meteorological meso-scale model, MM5V1, is implemented as a meteorological driver for the tracer model. The model system is used for studying transport and dispersion of air pollutants caused by a single but strong source as, e.g. an accidental release from a nuclear power plant. The model system including the coupling of the Lagrangian model with the Eulerian model are described. Various simple and comprehensive parameterizations of the mixing height, the vertical dispersion, and different meterological input data have been implemented in the combined tracer model, and the model results have been validated against measurements from the ETEX-1 release. Several different statistical parameters have been used to estimate the differences between the parameterizations and meterological input data in order to find the best performing solution.     

Validation of the operational emergency response model at the Swedish Meteorological and Hydrological Institute using data from etex and the chernobyl accident

The Eulerian atmospheric tracer transport model MATCH (Multiscale Atmospheric Transport and Chemistry model) has been extended with a Lagrangian particle model treating the initial dispersion of pollutants from point sources. The model has been implemented at the Swedish Meteorological and Hydrological Institute in an emergency response system for nuclear accidents and can be activated on short notice to provide forecast concentration and deposition fields.The model has been used to simulate the transport of the inert tracer released during the ETEX experiment and the transport and deposition of ¹³⁷Cs from the Chernobyl accident. Visual inspection of the results as well as statistical analysis shows that the extent, time of arrival and duration of the tracer cloud, is in good agreement with the observations for both cases, with a tendency towards over-prediction for the first ETEX release. For the Chernobyl case the simulated deposition pattern over Scandinavia and over Europe as a whole agrees with observations when observed precipitation is used in the simulation. When model calculated precipitation is used, the quality of the simulation is reduced significantly and the model fails to predict major features of the observed deposition field.     

沈阳市某装备制造产业园地下水污染物运移模拟研究

为摸清沈阳市某装备制造产业园地下水污染运移规律,科学指导当地生态环境管理部门开展工作,以该园区为研究对象,采用有限差分法,建立了该区域地下水水流数值模型,并利用地下水数值模拟软件(GMS软件)模拟预测了连续源强和瞬态源强污染物泄漏情景下1年、5年、10年及20年后污染物在地下水中的运移情况.经计算得到结论如下:①连续源...     

Integrating channel design and assessment methods based on sediment transport capacity in gravel bed streams

Natural channel design (NCD) and analytical channel design (ACD) are two competing approaches to stable channel design that share fundamental similarities in accounting for sediment transport processes with designs based on hybrid fluvial geomorphology and hydraulic engineering methods. In this paper, we highlight the linkage between ACD's capacity/supply ratio (CSR) and NCD's sediment capacity models (FLOWSED/POWERSED), illustrating how ACD and NCD have reached a point of convergent evolution within the stream restoration toolbox. We modified an existing CSR analytical spreadsheet tool which enabled us to predict relative channel stability using both conventional bed load transport equations and regional sediment regression curves. The stable channel design solutions based on measured data most closely matched the Parker (ACD) and/or Pagosa good/fair (NCD) relationships, which also showed the greatest CSR sensitivity in response to channel alterations. We found that CSR differences among the transport relationships became more extreme the further the design width deviated from the supply reach, suggesting that a stable upstream supply reach may serve as the best design analog. With this paper, we take a step toward resolving lingering controversy in the field of stream restoration, advancing the science and practice by reconciling key differences between ACD and NCD in the context of reach scale morphodynamics.     

地下水DNAPLs污染的研究进展

地下水有机污染特别是DNAPLs污染是当前国际上地下水污染控制的热点问题。本文综述了DNAPLs的监测技术、DNAPL在含水层的迁移及DNAPb污染场地修复技术的研究进展。     

反硝化细菌、硝酸钙和锆改性沸石联用对底泥中氮磷迁移转化的影响及硝态氮释放风险评估

本文考察了基于反硝化细菌、硝酸钙和锆改性沸石的组合技术（CN+DB+ZZ）对底泥中氮磷迁移转化的影响,并探讨了该技术的硝态氮释放风险.结果发现,单一的硝酸钙处理（CN）虽然可以有效地抑制底泥中磷的释放,但是会造成上覆水体的氨氮和硝态氮污染.硝酸钙和反硝化细菌联合处理（CN+DB）尽管可以有效地抑制底泥中磷的释放,并降低上覆水体的硝态氮二次污染风险,可是却无法有效地控制底泥中氨氮的释放.硝酸钙和锆改性沸石联合处理（CN+ZZ）虽然可以有效地抑制底泥中磷和氨氮向上覆水体的释放,但却会造成上覆水体硝态氮的二次污染.CN+DB+ZZ组合处理技术不仅可以有效地控制底泥中磷的释放,而且可有效降低底泥中氨氮的释放速率,并且与CN和CN+ZZ技术相比还可降低上覆水的硝态氮二次污染风险.CN+DB+ZZ组合技术对底泥中磷与铁同步释放的抑制、对底泥中氧化还原敏感态磷的削减、以及对底泥吸附磷酸盐和氨氮能力的增强,对于其控制底泥中磷和氨氮的释放是至关重要的.以上结果说明,CN+DB+ZZ组合技术是一种非常有希望的用于控制水体底泥中磷和氨氮释放的方法.     

雌激素在地下环境中的归宿及其生态调控

综述了环境中典型的结合态与游离态类固醇雌激素的来源、危害以及环境归趋,探讨了其在地下环境（土壤和浅层地下水系统）中的吸附、微生物降解等迁移转化过程及其影响因素,总结了常见的环境雌激素处理方法与危害控制措施.最后,针对目前环境中类固醇雌激素在包气带与浅层地下水中的穿透过程及其生态效应研究工作的基础上,对未来相关方面的研究进行了展望.     

基于星地同步观测的华北平原中部背景地区冬季霾污染过程

利用地基观测结果和多源卫星遥感观测,结合气象数据及HYSPLIT4后向轨迹模式,对华北平原中部背景地区(河南省郑州市中牟县东南郊)冬季霾事件的污染物特征和形成过程进行分析.综合观测时间为2014年12月13日~2015年1月16日,共有5次霾过程,占观测总天数的82%.地面监测结果显示,不同的污染过程污染物浓度变化曲线相似,O₃浓度在清洁天浓度较高;NO_x、SO₂、PM₁₀、PM_2.5呈较强正相关性,NO_x、SO₂与 PM₁₀相关系数0.64、0.57,与PM_2.5相关系数0.56、0.45;近地面污染物以细粒子污染物为主,其中又以气态污染物二次生成的细粒子为主.AMPLE地基激光雷达和CALIPSO数据表明,华北平原霾层中上部受浮尘影响,以粗粒子污染物为主.气象探空数据表明该地区冬季大气对流层稳定利于霾的维持,假相当位温垂直差、K指数、露点差与能见度相关系数分别为0.52、0.56和 0.38.分析近地面风速风向对霾过程的影响表明,该地区冬季以南方向静小风为主,风速与能见度相关系数为0.32 ,PM₁受东北方向污染源影响,PM_1~2.5及PM_2.5~10受西北方向污染源影响;结合高空风场分析,霾过程1受西北浮尘影响,霾过程5受南来水汽影响.通过后向轨迹分析,该地区冬季的低空污染传输主要来自东北和西北方向,其中东北方向区域传输来自河北与山东,占来源比例的14%,近距离污染传输主要来自站点以西的郑州、洛阳,约占来源比例的33%.