Application of graph overlay method to environmental impact assessment of railway noise

The graph overlay method is used to evaluate the noise impact of route alignment and the results can serve as a reference for the route alignment optimal selection. The geographic information system(GIS), with its powerful function of handling attribute data and spatial analysis, is adopted to calculate the noise comprehensive impact area of each alignment. With the graph overlay method, the noise vulnerability and noise impact distribution are both taken into account in the noise impact assessment of route alignment. With GIS, the efficiency of work and the reliability of result are greatly improved. By a combination of them, the noise impact on environment is fully presented in a visual way and the assessment result has vital value in route alignment optimal selection. A detailed case study is illustrated and the efficiency of the method is verified.     

Comprehensive assessment method for environmental impact of railway based on geographic information system

By integrating the merits of the map overlay method and the geographic information system (GIS), a GIS based map overlay method was developed to analyze comprehensively the environmental vulnerability around railway and its impact on the environment, which is adapted for the comprehensive assessment of railway environmental impact and the optimization of railway alignments. The assessment process of the GIS based map overlay method was presented, which includes deciding the system structure and weights of assessment factors, making environmental vulnerability grade maps, and evaluating the alternative alignments comprehensively to obtain the best one. With the GIS functions of spatial analysis, such as overlay analysis and buffer analysis, and functions of handling attribute data, the GIS based map overlay method overcomes the shortcomings of the existing map overlay method and the conclusion is more reasonable. In the end, a detailed case study was illustrated to verify the efficiency of the method.     

公路景观环境影响评价方法研究

阐述了公路景观评价的相关概念，以及公路景观评价的目的及其评价的特点等。在此基础上，建立了公路景观环境影响评价指标体系，并运用综合指数法对公路景观进行评价，总结了促进我国公路景观评价工作的几点建议。     

基于多尺度图像融合信息的沥青路面三维成像方法

基于图像处理的沥青路面纹理三维重建技术具有快速、全面、分辨率高等优点，针对沥青路面颜色集中、特征点不明显导致三维纹理检测精度低的问题，提出一种基于多尺度图像融合的双目视觉技术。通过加权最小二乘滤波实现图像多尺度分解，利用跨尺度聚合模型融合多尺度图像信息进行沥青路面三维重建，提高了双目重建的精度。通过区域纹理参数，将所提方法与激光扫描仪进行了比较。结果表明，所提方法的区域纹理参数结果与激光扫描仪的结果比较接近。     

图像处理下的粗集料形态特征研究

数字图像处理技术能够快速准确的提取粗集料的形态特征数据，进行粗集料形态特征评价。将粗集料的图像导入计算机利用Matlab软件进行图像处理，粗集料的图像经过消除噪声、图像分割、二值化、边缘提取以及颗粒数据分析，进而得到粗集料形态特征指标参数，包括粗集料长短轴、粗集料矩形度、粗集料圆形度、粗集料棱角性以及粗集料针片状含量。对粗集料图像进行分析处理后发现图像处理技术能够快速提取粗集料的特征参数，且比人工间接测量方法更加快捷准确。研究表明：最小阈值法能够很好地提取出粗集料的轮廓图像，进而完成粗集料图像的参数采集。石灰岩粗集料矩形度随着棱角性、长轴的增大而呈减小的趋势，石灰岩粗集料圆度随着棱角性、长轴的增大而呈增大的趋势；石灰岩粗集料颗粒的棱角性随长轴变化并不明显，曲线趋于平缓，样本棱角性在1.1左右，角度变化并不大；石灰岩粗集料针片状含量为0。研究有助于提升粗集料颗粒的质量控制，控制沥青混凝土使用性能，推动集料检测技术发展。