Evaluation Method and Application of Ecological Sensitivity of Intercity Railway Network Planning

In the planning stage of the intercity railway network, the ecological sensitivity evaluation of the planning scheme is not only the key content to explore the ecological environmental rationality of the planning scheme but also a scientific means to promote the sustainable development of intercity railway networks. The purpose of this study is to establish an evaluation method that can quantitatively evaluate the ecological sensitivity of intercity railway network planning to put forwards targeted optimization and adjustment suggestions for the planning scheme. Taking the intercity railway network planning of Guizhou Province as an example, its ecological sensitivity is predicted and evaluated. Six types of ecologically sensitive areas were selected as ecological sensitivity evaluation factors, including protected areas, drinking water sources, geological disaster-prone areas, soil erosion areas, cultivated land resource distribution areas and coal resource distribution areas. Based on the GIS overlay method, the quantitative measurement methods of each evaluation factor are established in turn, and the single factor sensitivity evaluation index is obtained. In addition, the weighted superposition model is used to quantitatively calculate the ecological sensitivity of the planned lines of the intercity railway network in Guizhou Province. Finally, the short board factor of each planned line is obtained, and targeted optimization and adjustment suggestions are put forwards. The research content of this paper can provide a theoretical reference for the practical evaluation of the ecological sensitivity of intercity railway network planning.

Bilevel Optimization of Intercity Railway Alignment

Intercity railway transit is the primary way to transfer passengers and freight over long distances on land. The design of an intercity railway alignment is usually challenging and complex because of great topographic variations and intersections with many existing geographic objects. This paper presents a bilevel optimization model for intercity railway alignment (BRAO) following the horizontal-vertical alignment design philosophy. The upper level is the horizontal alignment optimization, while the nested lower level is the vertical alignment optimization. A multistage augmented differential evolution algorithm is adopted for the solution at both levels. BRAO could generate corridor alignment, initial alignment, and optimal alignment through different allocations of the number and boundaries of decision variables. A real-world case study of railway design is conducted to verify the effectiveness of the BRAO model based on a geographic information system.

CHANGES IN THE PARAMETERS OF FUNCTIONING OF INTERCITY PASSENGER TRANSPORTATION SYSTEM

The speed of communication on any route, directly and indirectly through the function of redistribution of traffic volumes, causes an increase in the number of movements, traffic volumes, transport work, in the network of the appropriate type, at the same time the values of the medium system coefficient of passenger capacity use and the number of vehicles may vary both in the direction of the increase and vice versa. The results of the calculations of the basic parameters of the functioning of intercity passenger route systems for various values of the speed of communication on intercity railway routes established the appropriate mathematical model for determining the parameters of this passenger communication.