Accurate volume calculation of each individual landslide triggered by strong historical earthquakes can help understand the characteristics of the typical earthquake-induced landslides,thus providing significant information for the modification of the focal parameters of historical earthquakes.In this study,we select one rock fall and three loess landslides triggered by the 1556 AD Huaxian M8（1/2） earthquake,compute their volumes using the low-altitude high-precision Unmanned Aerial Vehicle（ UAV）photogrammetry and landslide profile restoration methods.The results show that:（1） the whole influencing area of the Huangjiagou Rock Fall is approximately 3.03 ×10～5 m2 and the area of the collapsed rock accumulated at the slope foot is 3.33 × 10～4 m2,accounting for approximately 10% of the entire influencing range.However,the estimated volume of the collapsed rock is only 0.699 × 106 m3,indicating a rock fall with large influencing range but limited collapsed rock;（2） the geological form of thethree loess landslides are preserved intactly,with volumes of 0.283 × 10～8 m3,0.074× 10～8 m3,and 0.377 × 10～8 m3.These important geological hazard relics reflect the strong vibrations and severe casualties in the meizoseismal area;（3） loess landslides are the key reason of the serious death toll in the hilly-gully loess area.Our new method can be used to estimate the influencing area and the actual volume of each individual landslide,and rationally evaluate the role of earthquake landslides in the disaster.In addition,quantitative research on secondary disasters triggered by strong historical earthquakes is beneficial for understanding the surface process and focal parameters of the earthquakes.
