Review on the connotation and methods of emergency investigations to geological hazards in mountainous area

Emergency investigations of geological hazards are immediate surveys to sudden geological hazards or dangerous situations. Real-time information should be provided timely during the survey period of one to several days， and the emergency investigation report should be submitted as soon as possible， so as to provide scientific basis and technical support for emergency rescue and management of geological hazards. Such emergency surveys are divided into two types，single point and a mass of geological hazards survey according to the technical conditions of surveys. This paper describes the main workflow of surveys including basic data preparation， on-site coordination meetings， decision-making and coordination arrangement， satellite and UAV remote sensing surveys， field emergency surveys， data integration research and report compilation， as well as the main working methods of each link. In general a geological hazard emergency survey adopts convenient and effective methods， such as field investigations and visits， geological mapping and satellite positioning， high-resolution satellite remote sensing， and aerial photography by UAV. In addition， the basic rules， methods and technical requirements of geological hazard emergency survey in mountainous areas are analyzed and reviewed in detail in this paper.