Abstract. A magnitude 7.0 earthquake struck Jiuzhaigou County, Sichuan Province at 21:00 on August 8, 2017, and the epicentre was located in the major tourist spot of Jiuzhaigou. This paper describes the surveying and mapping project of post-earthquake hazards regions for the restoration and reconstruction purposes. The earthquake triggered thousands of collapses and landslide disasters, causing severe damage to tourist land scapes and scenic roads such as Jiuzhaigou Panda Sea. The geological hazards of steep mountains and steep slopes and dense vegetation in the scenic area are highly concealed. Traditional susceptibility mapping methods for geological hazard using only airborne images have encountered great difficulties. Aiming to solve this issue, airborne LiDAR and high-resolution images were used jointly to interpret geological disasters in this area. The three-dimensional interpretation signs of disasters are established comprehensively by using optical images and digital elevation models to obtain the distribution characteristics of existing geological hazards, coseismic geological hazards and hidden dangers, which support the restoration and reconstruction of the tourist spots.

Abstract. The metro cabin provides an effective way for the spread of the pneumonia virus when provides convenience to human beings. The cabin undergoes a series of motions of acceleration speed, uniform speed, and deceleration speed during the one-station travelling process. The induced flow of the accelerated moving cabin is the determinant of the air drag force on the cough droplets, and effect on the time-frequency characteristics and motion trajectories of droplets of different sizes. In this study, we established a momentum equation on droplets, affected by the inertial force correction term in the non-inertial frame. Then added the drag force from the velocity difference between the cough droplets and the background airflow, and simulated configurations as: 1) droplet spreading aerodynamic process from different face orientations of infected dummy, 2) six groups of size particles, and 3) variable speed motion phases. The numerical simulation provides a physical analysis idea for studying the relationship between the two-phase flow under the action of inertial force. This design of a ventilation environment in public transportation helps to reach a more profound understanding of the inertial precipitation mechanism of droplet jets.