The GIS-based spatial optimization model for high-speed railway location in complex topographic regions

High-speed railway location is a complex engineering challenge with major implications for transportation and economic development, where terrain slope critically impacts feasibility, cost, and operational efficiency. Geographic Information System (GIS) technology, with powerful spatial analysis and visualization capabilities, is essential for environmental monitoring, ecological protection, and commercial development, supporting sustainable development and the growing demand for dynamic geographic information. This paper leverages GIS technology for terrain analysis to quickly identify areas meeting slope requirements for high-speed railway siting, providing directional guidance while reducing terrain management costs and environmental impact during construction. In this study, a region in southeast China is selected as the research area. Through slope analysis and classification of the area into different slope intervals, the study identifies regions suitable and unsuitable for high-speed railway location. ArcGIS 10.8.1 software is employed as the topographic analysis tool, utilizing free digital elevation data from the geospatial data cloud. The results show that areas with slopes between 0% and 5% are most suitable for high-speed rail construction, those with slopes from 5% to 30% serve as alternative options requiring terrain modification, while areas with slopes over 30% are unsuitable for construction. By enabling rapid identification of suitable areas, this GIS-based study enhances the efficiency and accuracy of high-speed railway site selection, greatly reducing the workload and cost of on-site surveys. Besides, it provides preliminary regional guidance and practical support for planning decisions.