山区铁路的长、特长隧道多在高大的分水岭地区,那里不仅自然条件十分恶劣而且工程地质条件常常十分复杂,研究程度也很差,这使隧道工程地质勘测工作很困难,因此遥感地质工作就显得很必要了。西安—××线的秦岭越岭隧道就是一条特长隧道,三个方案的长度 Mountain railway long and extra long tunnel in the tall watershed area, where not only the natural conditions are very poor and the engineering geological conditions are often very complicated, the study is also very poor, making the tunnel engineering geological survey is very difficult, so remote sensing geology work appears Very necessary. Xi’an - × × Qinling Ridge Tunnel line is a long tunnel, the length of the three programs