A classification method of building structures based on multi-feature fusion of UAV remote sensing images

In order to improve the accuracy of building structure identification using remote sensing images,a building structure classification method based on multi-feature fusion of UAV remote sensing image is proposed in this paper.Three identification approaches of remote sensing images are integrated in this method:object-oriented,texture feature,and digital elevation based on DSM and DEM.So RGB threshold classification method is used to classify the identification results.The accuracy of building structure classification based on each feature and the multi-feature fusion are compared and analyzed.The results show that the building structure classification method is feasible and can accurately identify the structures in large-area remote sensing images.

Landslides Triggered by the 2020 Qiaojia M_(w)5.1 Earthquake, Yunnan, China: Distribution, Influence Factors and Tectonic Significance

On May 18, 2020, an M_(w)5.1 earthquake occurred in Qiaojia County, Yunnan Province, China. This moderate-sized event triggered massive coseismic landslides, resulting in some damage. In this work, through visual interpretation of high-resolution(0.8–2 m) Gaofen satellite images before and after the earthquake, 167 landslides were delineated, 18 of which were inspected in the field. Using the landslide number density(LND) and landslide area percentage(LAP), we characterized the spatial distribution of these landslides, and analyzed their possible influence factors and tectonic significance. The results show that these landslides are distributed mostly in the NW-SE direction, roughly parallel to the long axis of seismic intensity zones and the strike of the Xiaohe-Baogunao fault(XBF). The LND and LAP decrease with increasing distances to the fault and from the epicenter to fault ends of the XBF. These permit to suggest that the seismogenic fault of the Qiaojia earthquake is likely a hidden branch of the XBF. All of the landslides induced by this event occurred in the region with the seismic intensity of six degrees or greater of the 2014 M_(w)6.2 Ludian earthquake. Therefore, it was inferred that the 2020 Qiaojia earthquake was probably the subsequent release of accumulated elastic strain after the 2014 Ludian earthquake in a same tectonic stress regime.