RESEARCH ON THE RELATIONS BETWEEN LOESS-BEDROCK UNCONFORMITY SURFACE AND LANDSLIDE IN LANZHOU AREA

Landslides are commonly in loessland which has close relation to loess-bedrock unconformity surface. Furthermore, it is very necessary to conduct prevention and controlling of geological disasters by deeply analyzing the controlling effect of the unconformity surface on loess landslides. Taking Lanzhou area as the research object, this paper discusseed the spatial relationship between density and volume of landslide and the loess-bedrock unconformity surface through the analysis of landslide distribution and general characteristics. The results show that:(1) the length, width, area and volume of landslide present a concentration on certain range along with the increasing of the landslide scale; (2) the correlation between width and volume of the landslide is worse, whereas better correlation presents between length and volume of the landslide, and the fitting relationship between landslide scale indicates that the characteristic of discrete increase with the increasing of landslide scale; (3) landslides are almost symmetrically distributed on the both sides of unconformity surface, moreover a large quantity of loess-bedrock landslides in great size are relatively developed near the unconformity surface; (3) between amount and volume of landslide and the distance of loess-bedrock unconformity surface obeys piecewise power-law distribution.