Cadna/A噪声预测软件在隧道洞口噪声预测中应用

本文对cadna/A环境噪声预测软件中的隧道口噪声预测原理做了详细的介绍,将隧道洞口的噪声影响简化为与隧道洞口形状一致的简单垂直面源,利用隧道参数计算面源的声功率级,预测方便,并通过实例应用和演示,为正确使用该软件进行噪声预测和同类工程环境影响评价提供参考。     

基于Cadna/A的石化项目声环境影响研究

采用Cadna/A噪声预测软件模拟石化建设项目声环境影响,分别预测厂内和厂界噪声值。依据模拟结果,厂界处噪声超标,通过噪声优化设计,提出降噪解决措施,在不改变工艺流程设计和设备选型的情况下,依据噪声源的频谱特性、噪声强度及所处位置,可采取隔声、消声、吸声、隔振、阻尼减震等噪声治理措施。对降噪后厂区现场实测,结果满足GB 3096-2008《声环境质量标准》、GB 12348-2008《工业企业厂界环境噪声排放标准》、GB Z1-2010《工业企业设计卫生标准》、GBZ 2.2-2007《工作场所有害因素职业接触限值第2部分:物理因素》等。     

基于BP模型对城市交通噪声的数据处理和预测

城市交通噪声的预测和评价技术是城市交通可持续发展的重要研究内容,直接为城市交通规划中环境容量分析和环境影响评价服务。本文通过实测的大量数据,运用神经网络中的BP模型及其算法建立车辆数、道路宽度和交通噪声之间的关系,对城市道路交通噪声数据进行处理和预测。     

基于Cadna/A软件的110kV户外变电站噪声预测模型研究

简述了110kV变电站噪声源特性。以邻港变电站作为噪声预测研究对象,利用Cadna/A软件分别对5种主流的110kV户外变电站噪声预测模型进行仿真预测。通过预测值与实测值的对比分析表明:110kV户外变电站采用水平+垂直面声源模型能较好地反映变电站噪声衰减情况,并对声源尺寸及源强选取、噪声控制方案提出了建议。     

大连金州区城市交通噪声的监测分析与防治对策

通过对大连市金州区城市交通噪声污染状况进行调查、监测,发现城市交通噪声污染状况不容忽视,提出了扩建城市环城公路、拓展和平整路面、噪声技术治理以及加强城市交通管理等城市交通噪声综合防治的对策。     

对环境影响评价中常用的几种公路交通噪声预测模式的适用性研究

道路交通噪声预测是公路建设环境影响评价中一个重要的环节,它对我们判断、分析公路交通噪声对沿线保护目标的影响程度,以及针对影响采取何种有效措施有积极的作用;本文重点就目前环评中常用的几种公路噪声预测模型对省内已建成的不同等级公路进行噪声预测,并与其实际监测结果进行对比分析,据此,论述在相同争件下各种预测模式计算结果产生误差的原因,得出各种噪声预测模式的适用性结论。     

机场飞机噪声的预测研究

本文以机场飞机噪声为研究对象,采用国际民航组织推荐使用的计权等效连续感觉噪声级(LWECPN)为评价量,以广汉机场为例,通过定量分析,利用MATLAB拟合出机场周围各监测点飞机噪声与跑道中心线对数距离的线性方程,然后将该方程用于对未知监测点的LWECPN预测,并与实测数据对比检验其准确度。结果表明,采用该线性拟合预测方法所得到的未知监测点的噪声预测值与实测值较为接近,两者的相对误差保持在1.0%到2.0%之间,预测准确度较好。值得一提的是,该方法操作相对简便,可以达到快速预测机场周边噪声敏感点LWECPN的目的,为今后飞机噪声的预测研究提出一种新的预测方法,具有一定的实际意义。     

大连市交通噪声环境质量二级模糊综合评价

采用基于模糊数学的综合二级评判方法评价大连10条城市道路交通环境噪声污染程度。结果表明,受交通噪声冲击影响最大的是西安路大连商业城居民小区路段,影响最小的是如意街大连商业城居民小区路段,与实际调查结果基本一致,体现了该评价方法的合理性和科学性。     

洞井新城建设中的交通噪声预测与控制规划

洞井新城在建成小城镇的过程中，声环境规划不可或缺，该区目前突出的是交通噪声，因而声环境规划的重点也就落在了对交通噪声控制的规划上。通过对交通噪声调查与评价、预测并作出合理规划，我们相信，规划区的交通噪声控制一定能够达到预期目标。     

灰关联熵分析方法在城市交通环境噪声研究中的应用

灰关联分析在城市环境噪声研究中是一种非常有效的手段。作者采用基于信息熵理论的灰关联熵分析方法对广州市交通噪声进行分析,指出了影响其变化的优势因素,为噪声污染防治提供了科学依据。     

Scenario‐Based and Scenario‐Neutral Assessment of Climate Change Impacts on Operational Performance of a Multipurpose Reservoir

Scenario‐based and scenario‐neutral impacts assessment approaches provide complementary information about how climate change‐driven effects on streamflow may change the operational performance of multipurpose dams. Examining a case study of Cougar Dam in Oregon, United States, we simulated current reservoir operations under scenarios of plausible future hydrology. Streamflow projections from the CGCM3.1 general circulation model for the A1B emission scenario were used to generate stochastic reservoir inflows that were then further perturbed to simulate a potentially drier future. These were then used to drive a simple reservoir model. In the scenario‐based analysis, we found reservoir operations are vulnerable to climate change. Increases in fall and winter inflow could lead to more frequent flood storage, reducing flexibility to store incoming flood flows. Uncertainty in spring inflow volume complicates projection of future filling performance. The reservoir may fill more or less often, depending on whether springs are wetter or drier. In the summer, drawdown may occur earlier to meet conservation objectives. From the scenario‐neutral analysis, we identified thresholds of streamflow magnitude that can predict climate change impacts for a wide range of scenarios. Our results highlight projected operational challenges for Cougar Dam and provide an example of how scenario‐based and scenario‐neutral approaches may be applied concurrently to assess climate change impacts.     

A Regional‐Scale Habitat Suitability Model to Assess the Effects of Flow Reduction on Fish Assemblages in Michigan Streams1

Zorn, Troy G., Paul W. Seelbach, and Edward S. Rutherford, 2012. A Regional‐Scale Habitat Suitability Model to Assess the Effects of Flow Reduction on Fish Assemblages in Michigan Streams. Journal of the American Water Resources Association (JAWRA) 48(5): 871‐895. DOI: 10.1111/j.1752‐1688.2012.00656.x Abstract: In response to concerns over increased use and potential diversion of Michigan’s freshwater resources, and the resulting state legislative mandate, an advisory council created an integrated assessment model to determine the potential for water withdrawals to cause an adverse resource impact to fish assemblages in Michigan’s streams. As part of this effort, we developed a model to predict how fish assemblages characteristic of different stream types would change in response to decreased stream base flows. We describe model development and use in this case study. The model uses habitat suitability information (i.e., catchment size, base‐flow yield, and July mean water temperature) for over 40 fish species to predict assemblage structure in an individual river segment under a range of base‐flow reductions. By synthesizing model runs for individual fish species at representative segments for each of Michigan’s 11 ecological stream types, we developed curves describing how typical fish assemblages in each type respond to flow reduction. Each stream type‐specific, fish response curve was used to identify streamflow reduction levels resulting in adverse resource impacts to characteristic fish populations, the regulatory standard. Used together with a statewide map of stream types, our model provided a spatially comprehensive framework for evaluating impacts of flow withdrawals on biotic communities across a diverse regional landscape.