城市轨道交通站台噪声测量研究

为研究城市轨道交通高架和地下站台噪声的规律和特点,选取某条线路中的3个高架站台以及3条线路中的7个地下站台进行实地测量,并对测量结果进行分析。研究结果表明:地下站台LAeq值都低于标准限值80 dB(A);站台的中心测点列车进站LAeq值和列车出站LAeq值都非常接近,使用T检验结果得出各站台中心测点列车进站LAeq值和列车出站LAeq值不存在显著差异（P>0.05）;站台测量时要考虑大客流带来的喧闹声;站台最大噪声值是列车出站时,位于站台列车车头停止位置。     

盐分和淹水增加对河口潮汐淡水沼泽湿地土壤磷形态和磷酸酶活性的影响

选取中国东南沿海闽江河口潮汐淡水沼泽湿地土壤作为研究对象,研究不同盐分(淡水对照、低盐处理、高盐处理)和不同淹水(CK、CK+15 cm、CK+30 cm)交互处理对土壤磷形态和磷酸酶活性的影响.结果表明,在闽江河口潮汐淡水沼泽湿地土壤中,无机磷是土壤总磷的主要赋存形态,约占总磷含量的68%~82%,有机磷含量约占总磷的18%~32%.无机磷以铁铝结合态磷为主(60%~66%),其次为钙结合态磷和闭蓄态磷.淹水处理对磷的总量和形态的影响有限,盐分变化对磷的总量和形态影响显著.低盐处理可增加铁铝结合态磷、闭蓄态磷含量及碱性磷酸酶活性,而高盐处理则对它们表现出抑制作用.随着盐分的增加,土壤总磷含量逐渐降低,土壤中钙结合态磷含量和磷酸盐含量将逐渐升高.相关分析表明,有机磷含量与土壤碱性磷酸酶活性呈负相关,无机磷含量与土壤碱性磷酸酶活性呈正相关.当盐分由淡水变化至低盐时,土壤磷的形态主要由有机磷向无机磷转化;而当盐分由低盐变化至高盐时,无机磷占比降低,有机磷占比增加.研究结果表明,碱性磷酸酶活性在磷形态对盐分和淹水的响应中发挥着重要作用.     

Evolution of urban black and odorous water: The characteristics of microbial community and driving-factors

Urban black blooms that are primarily caused by organic carbon are deleterious environmental problems. However, detailed studies on the microbial characteristics that form urban black blooms are lacking. In this study, we observed the composition, diversity, and function of bacterial community in the overlying water and sediments during the occurrence and remediation of urban black blooms using high-throughput 16S rRNA gene amplicon sequencing analysis. First, we found that pivotal consortia in ...     

长江荆江分蓄洪区历史演变、前景和风险管理

依据社会经济统计数据、水文资料、遥感影像信息和实地调查资料，分析了荆江分蓄洪区在历史演变过程中形成的分洪与发展的矛盾及其在未来长江流域防洪体系中的重要作用，指出其风险管理的必要性。运用基于GIS栅格数据的二维水动力洪水动态演进模型，对荆江分蓄洪区1954年的分洪过程进行了模拟和验证，模拟了不同分洪规划方案下的洪水淹没范围，水深和水位，并结合现阶段社会经济发展情况，定量估算了农户和农业的分洪可能损失。在分洪损失评估基础上提出了荆江分蓄洪区引导人口合理发展、促进土地有效利用、开展防洪教育、实施洪水保险和确保安全运用预案等减轻洪水损失提高运用机率的洪水风险管理初步方案。     

Mitigating flood risk and enhancing community resilience to natural disasters: plan quality matters

In response to increasingly frequent and severe flooding events, tracking the explanatory elements of integrative planning effort can provide useful assessment of initiatives that foster improved community disaster resiliency. In this research, we address the effect of local hazard mitigation plan quality on mitigating disaster risk with an emphasis on the relationship between plan quality and community resilience. Using content analysis and principles of plan quality metrics, we evaluate local hazard mitigation plans to determine how well they support disaster risk reduction. Analytically, these metrics and relevant controls were incorporated into both a log-linear two-stage least squares model and a quantile regression model to explain flood loss at the county level for the US Mississippi River Basin. Findings suggest that better plan quality and high levels of community resilience result in reducing disaster losses.     

A Simple Stream Monitoring Technique Based on Measurements of Semiconservative Propertiesof Water

Correlative relationships exist among conductivity, alkalinity, and hardness in streams due to natural geological and climatological controls, but the relationships among these three water-quality factors can be altered strongly by inputs of ion-rich wastewaters. The degree of alteration can be monitored conveniently by use of a simple chemical perturbation index, computed by subtracting the sum of rank pairwise correlations among the conductivity, alkalinity, and hardness (for observations on each of these variables, measured through time) from 3.0. The chemical perturbation index can be used to document or characterize spatiotemporal changes in stream water quality. This study explains the development of the index's concept and provides examples of its application in an extensive stream monitoring program used to assess ecological conditions in streams on the Department of Energy's Oak Ridge Reservation in east Tennessee, USA. The chemical perturbation index technique may be particularly useful in community-based stream monitoring programs because to its simplicity and low cost.     

Modeling Energy Savings from Urban Shade Trees: An Assessment of the CITYgreen® Energy Conservation Module

CITYgreen® software has become a commonly used tool to quantify the benefits of urban shade trees. Despite its frequent use, little research has been conducted to validate results of the CITYgreen energy conservation module. The first objective of this study is to perform a familiar application of CITYgreen software to predict the potential energy savings contribution of existing tree canopies in residential neighborhoods during peak cooling summer months. Unlike previous studies utilizing CITYgreen, this study also seeks to assess the software’s performance by comparing model results (i.e., predicted energy savings) with actual savings (i.e., savings derived directly from energy consumption data provided by the electric utility provider). Homeowners in an older neighborhood with established trees were found to use less energy for air-conditioning than homeowners in a recently developed site. Results from the assessment of model performance indicated that CITYgreen more accurately estimated the energy savings in the highly vegetated, older neighborhood.     

库尔勒市绿地系统综合效益分析

城市绿地系统是城市中一种特殊的生态系统。随着社会的发展，城市绿地系统的生态效益、社会效益和经济效益，对于改善和恢复城市地区的生态环境质量，美化社会环境，进而促进整个城市经济发展，起着越来越重要的作用。以库尔勒市为例，阐述了城市绿地的生态、经济、社会效益，针对库尔勒市绿地建设提出了几点方案。     

论城市环境基础设施市场化运营中的政府规制

本文分别从市场准入、价格、服务质量以及风险等方面，对城市环境基础设施市场化运营中的政府规制进行了具体分析。     

Dynamics of household energy consumption in a traditional African city, Ibadan

In the last three decades the Nigerian environment has experienced rapid degradation. A major contributory factor of this phenomenon is the pattern of socioeconomic development in the country that gives little or no consideration to environmental outcomes. An aspect of this development is the economic policy of removal of subsidies on petroleum products initiated in 1986 as a result of the worsening economic situation in the country which begun in the early 1980s. The result of this is that prices of commercial fuels inclusive of kerosene and LPG (cooking gas) have continued to rise beyond the reach of majority of the Nigerian population. The paper examines the effect of increasing prices of petroleum-derived energy sources on the pattern of energy use for cooking in low and middle-income households and the environmental implication in Ibadan, the largest truly indigenous urban centre in sub-Saharan Africa. Results show that prior to the further subsidy removal of 1993, majority of households sampled used kerosene for cooking. Thereafter, a complete or partial switch in the pattern of domestic energy consumption ensued with more households using fuel wood and other more polluting and less efficient energy sources for cooking. The paper recommends a transition towards more environmental friendly energy sources for household use.