Creation of Large-Scale Maps for Engineering and Geodetic Works in the Mountainous Areas of Kyrgyzstan (on the Example of the Too-Ashuu Pass)

When constructing an alternative tunnel on the "Too-Ashuu" pass or reconstructing capital construction objects of the highway on the "Too-Ashuu" pass, the results of engineering and geodetic surveys should be topographic maps at scales of 1:5000–1:200. The scale of topographic surveying and terrain cross-section heights is selected considering the surveying conditions and final objectives. Therefore, in mountainous regions, a problem arises with large-scale maps for engineering and geodetic works due to distortions in the horizontal alignment and elevation points. To address this issue, the authors propose the use of a local transverse cylindrical projection and the stereographic Gauss projection without accounting for high mountainous conditions, which can be employed at scales of 1:5000 and larger. The Lambert conic projection at scales of 1:10,000 and larger. Considering the secant plane, the Lambert projection can be used to create maps at scales of 1:5000 and larger. Materials and methods: the evaluation of the results of the computational experiments was further performed according to existing requirements for the accuracy of topographic maps and plans. These are typically assessed using mean errors or root mean square errors (m). According to the theory of mathematical processing, the relationship between them is as follows: m = 1.25. When constructing an alternative tunnel on the "Too-Ashuu" pass or reconstructing highway capital construction objects in the "Too-Ashuu" area, the engineering and geodetic survey results should be topographic maps at scales of 1:5000–1:200. Considering the secant plane, the results with equal accuracy are obtained using both the local transverse cylindrical projection and the stereographic Gauss projection.