Response of the topography of Laixihe drainage to the structural deformation induced by M_S6.0 Luxian earthquake and its indication

Based on 12.5 m DEM data, the elevation profile and hypsometric integral （HI） of Laixihe drainage are extracted by digital geomorphological analysis method, and the response relationship between geomorphology and tectonic activity in the areas near the epicenter of Luxian M_S6.0 earthquake is analyzed. The results show that the Luoguanshan and Tiziya anticlines have obvious shortening differences between the north and south ends of the epicenter. The low HI value zone is consistent with the direction of the structure in the basin. The high HI value zone is located between the valleys clamped by the two faults of Huayingshan, but there is a low value zone in WNW direction near the epicenter. The comprehensive analysis shows that there should be a WNW-trending buried structure near the epicenter, which not only regulates the shortening difference between the north and south ends of the epicenter for the Luoguanshan and Tiziya anticlines, but also makes the HI value being a low value characteristic affected by it. The WNW direction of the buried structure is consistent with the results of the focal mechanism solution, major axis strike of isoseismal line, and the dominant predirection of spatial distribution of aftershocks.