城市废物流自然循环消纳及实现途径探讨

通过对城市的人工物流循环过程与环境的自然物流循环过程关系的讨论，提出环境问题是产生于两者之间的矛盾，环境治理应致力于协调两者关系，并体现在自然物流循环过程的恢复，以此思路为基础评述了不同类型城市环境治理措施对城市环境质量改善的可持续化效益，并提出了几种典型的城市废物流的自然循环消纳的实现途径，及其对自然物流循环恢复的意义。     

A Computational Fluid Dynamics Approach for Urban Area Transport and Dispersion Modeling

A simulation tool has been developed to model the wind fields, turbulence fields, and the dispersion of Chemical, Biological, Radiological and Nuclear (CBRN) substances in urban areas on the building to city blocks scale. A Computational Fluid Dynamics (CFD) approach has been taken that naturally accounts for critical flow and dispersion processes in urban areas, such as channeling, lofting, vertical mixing and turbulence, by solving the steady-state, Reynolds-Averaged Navier–Stokes (RANS) equations. Rapid generation of high quality cityscape volume meshes is attained by a unique voxel-based model generator that directly interfaces with common Geographic Information Systems (GIS) file formats. The flow and turbulence fields are obtained by solving the steady-state RANS equations using a collocated, pressure-based approach formulated for unstructured and polyhedral mesh elements. Turbulence modeling is based upon the Renormalization Group variant of the k–ε model (k–ε RNG). Neutrally buoyant simulations are made by prescribing velocity boundary condition profiles found by a power–law relationship, while turbulence quantities boundary conditions are defined by a prescribed mixing length in conjunction with the assumption of turbulence equilibrium. Dispersion fields are computed by solving an unsteady transport equation of a dilute gas, formulated in a Eulerian framework, using the velocity and turbulence fields found from the steady-state RANS solution. In this paper the model is explained and detailed comparisons of predicted to experimentally obtained velocity, turbulence and dispersion fields are made to neutrally stable wind tunnel and hydraulic flume experiments.     

Estimation of the amount of dry deposition in an urban area (Kobe city, Japan) by the inferential method

The amount of dry deposition of SO₂(g) and HNO₃(g) in an urban area in Japan has been estimated by the inferential method. The mean annual dry deposition of SO₂(g) (2.91 kgS/ha/year) was close to or less than that in the Clean Air Status and Trends Network (CASTNet) of the U.S. (3.59 kgS/ha/year). The mean annual dry deposition of HNO₃(g) (10.8 kgN/ha/year) was approximately six times larger than that in CASTNet (1.85 kgN/ha/year). The proportions of dry/(dry+wet) deposition for sulfur and nitrogen were 0.301 and 0.785, respectively.     

三峡工程对重庆城市排水管渠设施的影响及对策探讨

长江三峡水库建成后，因水位提高给库区内沿江城市现有城市排水设施带来了一定的影响。本文就三峡工程对重庆城市排水管渠设施的影响作了一些剖析，并对重庆城市排水管渠的建设提出了对策及设想。     

上海城市绿地系统建设与规划的原则和对策

针对上海城市绿化现状，强调生态位、生态效益、生物多样性、空间布局和景观割裂等原理在绿地中的重要性，并在此基础上分析探讨了２１世纪的上海在绿地系统建设中应如何提高绿化数量、改善绿地质量、提高生物的多样性和空间异质性、发挥生态效益、丰富绿化形式等诸多问题，尝试为今后的规划提供一些对策。     

长江,嘉陵江重庆段水污染控制规划

根据水质预测结果用组合规划的方法对长江，嘉陵江重庆干流段和城区段的水污染控制提出了多个不同的方案，并对各方案进行了比较，从水质，经费和施工的可行性３个方面综合评定，筛选出优先考虑方案，同时对方案实施后的效益作出了简要的叙述。     

苏州河的主要支流污染源及防治对策

采用现场察看和查阅资料的方法，对苏州河四支流彭越浦、木渎港、新泾港和真如港的部份市区污染严重段的污染源进行了调查研究，并根据等标污染负荷确定污染大户。在此基础上，结合支流底质及非点污染源的实况，提出了相应的防治对策。     

城市园林植物生态功能及其评价与优化研究进展

城市当前面临着越来越严重的环境问题.园林植物因其碳氧平衡、蒸腾吸热、吸污滞尘、减菌减噪、涵养水源、土壤活化和养分循环、维持生物多样性、景观功能、防灾减灾等生态功能在缓解城市环境压力方面起着至关重要的作用.为了使城市园林植物生态功能最大限度地发挥和城市生态环境得到较大改观,综述了国内外在城市园林植物生态功能及其评价与优化等方面的最新研究成果,分析研究中存在的不足之处.     

Multiscale Plume Transport from the Collapse of the World Trade Center on September 11, 2001

The collapse of the world trade center (WTC) produced enhanced levels of airborne contaminants in New York City and nearby areas on September 11, 2001 through December, 2001. This catastrophic event revealed the vulnerability of the urban environment, and the inability of many existing air monitoring systems to operate efficiently in a crisis. The contaminants released circulated within the street canyons, but were also lifted above the urban canopy and transported over large distances, reflecting the fact that pollutant transport affects multiple scales, from single buildings through city blocks to mesoscales. In this study, ground-and space-based observations were combined with numerical weather forecast fields to initialize fine-scale numerical simulations. The effort is aimed at reconstructing pollutant dispersion from the WTC in New York City to surrounding areas, to provide means for eventually evaluating its effect on population and environment. Atmospheric dynamics were calculated with the multi-grid Regional Atmospheric Modeling System (RAMS), covering scales from 250 m to 300 km and contaminant transport was studied using the Hybrid Particle and Concentration Transport (HYPACT) model that accepts RAMS meteorological output. The RAMS/HYPACT results were tested against PM2.5 observations from the roofs of public schools in New York City (NYC), Landsat images, and Multi-angle Imaging SpectroRadiometer (MISR) retrievals. Calculations accurately reproduced locations and timing of PM2.5 peak aerosol concentrations, as well as plume directionality. By comparing calculated and observed concentrations, the effective magnitude of the aerosol source was estimated. The simulated pollutant distributions are being used to characterize levels of human exposure and associated environmental health impacts.     

遥感图像上城市震害信息的获取及其应用

从震害分析和研究的目的出发，讨论了遥感图像资料在城市地震灾害评价中采用的震害信息分类、获取方式、表示方法及应用问题。