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。     

Reducing Streamflow Forecast Uncertainty: Application and Qualitative Assessment of the Upper Klamath River Basin,Oregon1

Abstract: The accuracy of streamflow forecasts depends on the uncertainty associated with future weather and the accuracy of the hydrologic model that is used to produce the forecasts. We present a method for streamflow forecasting where hydrologic model parameters are selected based on the climate state. Parameter sets for a hydrologic model are conditioned on an atmospheric pressure index defined using mean November through February (NDJF) 700‐hectoPascal geopotential heights over northwestern North America [Pressure Index from Geopotential heights (PIG)]. The hydrologic model is applied in the Sprague River basin (SRB), a snowmelt‐dominated basin located in the Upper Klamath basin in Oregon. In the SRB, the majority of streamflow occurs during March through May (MAM). Water years (WYs) 1980‐2004 were divided into three groups based on their respective PIG values (high, medium, and low PIG). Low (high) PIG years tend to have higher (lower) than average MAM streamflow. Four parameter sets were calibrated for the SRB, each using a different set of WYs. The initial set used WYs 1995‐2004 and the remaining three used WYs defined as high‐, medium‐, and low‐PIG years. Two sets of March, April, and May streamflow volume forecasts were made using Ensemble Streamflow Prediction (ESP). The first set of ESP simulations used the initial parameter set. Because the PIG is defined using NDJF pressure heights, forecasts starting in March can be made using the PIG parameter set that corresponds with the year being forecasted. The second set of ESP simulations used the parameter set associated with the given PIG year. Comparison of the ESP sets indicates that more accuracy and less variability in volume forecasts may be possible when the ESP is conditioned using the PIG. This is especially true during the high‐PIG years (low‐flow years).     

原油储罐火灾扬沸形成时间预测模型研究

扬沸火灾是一种突变性火害现象,其发生能导致巨大的人员伤亡和财产损失,其形成时间预测问题一直备受关注。根据能量守恒定律,把原油层内的热量传递看作无内热源、常物性的非稳态传热问题,建晓热量传递模型,通过预测油层内的温度分布,结合小尺度油罐扬沸火灾实验结果,推导出扬沸形成时间预测模型。并对其可靠性进行了案例验证,结果表明模型准确,误筹较小。实验发现随着罐径的增大,水层厚度对扬沸形成时间的影响逐渐减小。通过预测模型计算得到：扬沸形成时间与初始油层厚度和罐径的比值存在正比例关系。     

改进的灰色马尔科夫模型在飞行事故率预测中的应用

基于灰色理论和马尔科夫理论,建立传统的灰色预测模型和灰色马尔科夫预测模型;对传统灰色预测模型的背景值和初值的构造存在一定的误差进行改进,并用改进后的新模型对飞行事故率预测的结果与传统的灰色马尔科夫模型进行对比;仿真结果表明:改进后的灰色马尔科夫模型预测精度有了进一步的提高并验证了算法的有效性。     

Forest ecosystems of the volga basin under conditions of global climate warming: Local ecological prediction

Prediction based on one of the latest extreme prognostic models, the Hadley Centre Model HadCM3 (version A2) has been performed using an original method of discrete empirical statistical modeling of ecosystems. Probabilistic scenarios of the expected changes in summer soil moisture content until the mid-22nd century and corresponding structural and functional changes in forest ecosystems for different zonal/regional conditions of the Volga basin are described.     

空气中PM_(10)浓度的BP神经网络预报研究

建立了某市PM10浓度预报的分段BP神经网络模型,经验证,所建立的BP预报模型,预测精度比较高,PM10日平均浓度误差大多在-0．010～0．010mg／m^3范围内,相对误差在-20％～20％,表明BP神经网络对PM10的浓度预报是一种有效的工具。     

A High‐Resolution National‐Scale Hydrologic Forecast System from a Global Ensemble Land Surface Model

Warning systems with the ability to predict floods several days in advance have the potential to benefit tens of millions of people. Accordingly, large‐scale streamflow prediction systems such as the Advanced Hydrologic Prediction Service or the Global Flood Awareness System are limited to coarse resolutions. This article presents a method for routing global runoff ensemble forecasts and global historical runoff generated by the European Centre for Medium‐Range Weather Forecasts model using the Routing Application for Parallel computatIon of Discharge to produce high spatial resolution 15‐day stream forecasts, approximate recurrence intervals, and warning points at locations where streamflow is predicted to exceed the recurrence interval thresholds. The processing method involves distributing the computations using computer clusters to facilitate processing of large watersheds with high‐density stream networks. In addition, the Streamflow Prediction Tool web application was developed for visualizing analyzed results at both the regional level and at the reach level of high‐density stream networks. The application formed part of the base hydrologic forecasting service available to the National Flood Interoperability Experiment and can potentially transform the nation's forecast ability by incorporating ensemble predictions at the nearly 2.7 million reaches of the National Hydrography Plus Version 2 Dataset into the national forecasting system.     

年度地震重点监视防御区地震保险净费率的计算

根据我国年度地震重点监视区13年的预报结果和实际发生地震的结果,研究了这些地区地震保险净费率的计算方法。作为例子,给出了Ⅱ类地区基本烈度为Ⅵ度地区多层混凝土楼板砖结构Ⅶ度设防的建筑物的地震保险净损失率的计算结果。结果表明,我国年度地震重点监视区的地震保险净费率明显高于同类研究中不考虑其特殊地震危险性的结果。这一结果表明,中国的年度地震重点监视区是地震保险研究中应当给予特别关注的地区。     

道路交通噪声预测的研究进展

为评价道路交通噪声影响情况,以美国联邦公路管理局(FHWA)噪声预测模型为主,各国相继开发了基于当地实际情况的道路交通噪声预测模型,中国也以导则和规范等形式相继发布了各种交通噪声预测模型。中国进行噪声环境影响评价中,用得较多的主要有《环境影响评价技术导则声环境》(HJ 2.4—2009)、《公路建设项目环境影响评价规范》(JTG B03—2006)推荐的噪声预测模型,此外也有部分评价工作采用了德国的Cadna A软件。通过对比分析,HJ 2.4—2009的衰减及修正因素在综合考虑FH-WA噪声预测模型及JTG B03—2006基础上更加全面,而JTG B03—2006和Cadna A软件在源强和车速确定方面则均较成熟。有必要根据区域道路特点,选择适合特征区域的道路交通噪声预测模型,并结合实际情况对模型参数进行合理修正,最终形成一些可供区域参考的统一的模型修正参数,积极推动中国的声环境评价工作的发展。     

光源对光催化降解甲醛效果的影响及预测模型

利用环境测试舱模拟不同光源种类和光照强度下的室内环境,以甲醛溶液的光催化降解为探针反应,分析Ce-TiO2光催化降解甲醛溶液效果与光源的关系。并且采用指数平滑法中的3次指数平滑模型,建立Ce—TiO2光催化降解甲醛溶液效果的预测模型,预测结果表明实测值与预测值误差小,预测值精确度高,这为光催化降解甲醛溶液的研究,提供了一个新的思路。